Shedding kinetics of soluble tumor necrosis factor (TNF) receptors after systemic TNF leaking during isolated limb perfusion. Relevance to the pathophysiology of septic shock

We examined the kinetics of shedding of the soluble TNF receptors (TNF-Rs) in response to TNF leakage during isolated limb perfusion procedures and correlated them to the resulting hemodynamic effects. Shedding of the TNF-Rs started 7 min after TNF leakage into the systemic circulation. Three waves of shedding were observed peaking at 1, 8-12, and 48-72 h both in vivo and in cell cultures. The soluble receptors prolonged the half-life of TNF in the systemic circulation to 2.5-6 h. Excess shedding of the p75 compared with p55 TNF-Rs was noted during the first wave. The amount and speed of shedding of the p75 TNF-Rs were proportional to the serum TNF levels (P < 0.001). A maximal shedding capacity was attained only during the first wave of shedding, at TNF concentrations of approximately 1.5 ng/ml. Above this level, the linearity between TNF and its soluble receptors was lost. TNF-induced hypotension coincided with the initial imbalance between the concentrations of TNF and its soluble receptors. Despite the spontaneous correction of this imbalance at 8-12 h, the hemodynamic and biochemical alterations persisted and were further aggravated at 18 h, suggesting that other factors induced earlier by TNF are responsible for the perpetuation of the hemodynamic instability. This study may provide the basis for a more physiological therapeutic approach to TNF neutralization in septic shock patients.     

Systemic leakage during isolated limb perfusion for melanoma

A hazard of regional perfusion for melanoma is incomplete isolation, resulting in leakage of the cytostatic drug into the systemic circulation. Data were analysed retrospectively on 438 melphalan perfusions performed for melanoma of the extremities during the period 1978-1990; continuous isotopic measurement of systemic leakage was carried out. The cumulative systemic leakage after 60 min perfusion was 0.9 per cent (95 per cent confidence interval 0.7-1.1 per cent). Systemic leakage of > or = 1 per cent was detected in 12.6 per cent of perfusions, > or = 5 per cent in 6.2 per cent and > or = 10 per cent in 1.4 per cent. In 2.3 per cent of patients, systemic side-effects in the form of mild transient bone marrow depression occurred. Six variables related to the perfusion technique were assessed by multivariate analysis for their influence on systemic leakage. The level of isolation and diameter of the venous cannula emerged as significant factors. In addition, ligation of the internal iliac vein provided optimal isolation during iliac perfusion.     

Frequency and duration of remission after isolated limb perfusion for melanoma

OBJECTIVE: To determine changes of blood pressure and heart rate during apnoea testing for brain death without (A) and with (B) artificial CO2 augmentation. DESIGN: Prospective, consecutive study. SETTING: 12 intensive care units in six towns in Northern Bavaria. PATIENTS AND PARTICIPANTS: A total of 55 apnoea tests were performed on 55 consecutive patients as part of the determination of brain death, 27 without and 28 with CO2 augmentation. INTERVENTIONS: Apnoea tests following oxygenation with 100% O2 either after reduction of ventilatory volume (A) or after insufflation of CO2 during normoventilation (B). In each case, an arterial partial CO2 pressure of at least 8 kPa was documented. RESULTS: All apnoea tests were without serious adverse effects (hypoxia, newly induced cardiac arrhythmia, cardiac asystole). An increased dopamine infusion rate was deemed necessary in only one case of group (A) because of marked systolic hypotension (< 8 kPa). Individual variation of systolic and diastolic blood pressure (BP) did not exceed + 62 to -46% and + 49 to -52% respectively, in group (A) and + 35 to -57% and + 40 to -48% respectively, in group (B). Variation of heart rate (HR) remained within the range + 24 to -31% in group (A) and + 37 to -22% in group (B). CONCLUSIONS: HR varied less than BP. The possibility of a marked relative rise of fall of BP in group (A) was equal; in group (B) there was a lower change of rising BP. The chances for a rise or fall in HR were equal for the two groups. There was a tendency for less variation of cardiovascular parameters in group (B).     

Increased concentrations of tumour necrosis factor (TNF) and soluble TNF receptors in biliary obstruction in mice; soluble TNF receptors as prognostic factors for mortality

Erythema nodosum leprosum (ENL) is a serious complication of lepromatous (L) disease in leprosy. We have previously shown that of the four IgG subclasses, IgG1 and IgG3 Mycobacterium leprae-specific antibodies are significantly lower in leprosy patients during ENL reaction compared with untreated L patients. To see if this decrease results from a down-regulation of antibody synthesis during ENL, the frequency of antibody-secreting B cells (ABSC) in the blood compartment was determined by ELISPOT and related to serum immunoglobulin concentrations (microgram/ABSC). Control groups consisted of 16 patients with stable L disease and 32 healthy endemic controls (EC). Paired samples were analysed during acute ENLS (n = 13) and after the reaction had subsided to identify changes associated with ENL. Polyclonal (PC) IgG1 was elevated in L patients compared with EC (325 micrograms versus 180 micrograms). Interestingly, patients during acute ENL showed concentrations higher than L patients (419 micrograms), which decreased after the reaction had subsided (260 micrograms), indicating the transient nature of the antibody response. IgG2 antibodies showed the reverse trend and were lower during ENL and increased after the reaction had subsided. The mean concentrations for PC IgG3 and IgG4 antibodies were similar during ENL and after the reaction had subsided. Thus, decrease in M. leprae-specific IgG1 and IgG3 antibodies is not related to down-regulation of B cell responses. Identification of factors which regulate PC IgG1 antibody synthesis may provide additional insights into determinants of ENL reactions.     

Hyperthermic isolated limb perfusion with cis-diamminedichloro-platinum. II. An experimental study in dogs with a balloon-occlusion technique for repeated high-dose treatment

Isolated organ perfusion is attractive for regional high-dose chemotherapy because of its advantage to reduce whole body toxicity. Intraoperative hyperthermic isolated perfusion procedures involving a heart-lung machine have been developed, but repeated treatments carry a high risk of vessel and tissue damage. Therefore, a study of isolated hyperthermic limb perfusion in four dogs was conducted using a balloon-occlusion technique including a hyperthermia unit, two low-flow rotary pumps, a bubble oxygenator, and two polyurethane balloon catheters. After 15 min infusion of cisplatinum the concentrations of serum platinum (Pt) in the isolated limb and in the whole body were measured by atomic absorption spectroscopy. Regional exposure to Pt was more than 10-fold higher than systemic exposure. After 60 min isolated limb perfusion, the area under the curve (AUC) of Pt concentrations in the isolated limb showed values between 767.4 and 1055.6 micrograms/l x 60 min, whereas in the whole body values between 59.8 and 75.9 micrograms/l x 60 min were obtained. Repeated isolated limb perfusions with the balloon-occlusion technique were performed in three dogs without systemic side effects. This model of regional chemotherapy may be useful for preoperative chemotherapy in malignant tumors of the limbs.     

Isolated limb reperfusion with tumor necrosis factor and melphalan in patients with extremity melanoma after failure of isolated limb perfusion with chemotherapeutics

BACKGROUND: This retrospective study evaluated the benefit of using tumor necrosis factor (TNF) and melphalan administered via an isolated limb perfusion (ILP) in a series of patients with metastatic melanoma who failed initial ILP with chemotherapeutics. METHODS: Seventeen patients with extremity melanoma who underwent prior ILP with conventional chemotherapeutics (10 with melphalan; 4 with platinum; 2 with platinum, dacarbazine, thiotepa, actinomycin D, and nitrogen mustard; and 1 with thiotepa, actinomycin D, and nitrogen mustard) and had local recurrences were treated with a 90-minute isolated hyperthermic limb reperfusion with melphalan (10 mg/L limb volume) plus TNF (2-6 mg). Five prior ILPs were adjuvant and 12 were therapeutic. RESULTS: Reperfusion was associated with an overall 94% response rate and a 65% complete response (CR) rate. Of the patients who failed an initial ILP with melphalan alone the overall response rate was 90% after the reperfusion with TNF and melphalan. In patients who failed an initial ILP with agents other than melphalan the CR rate was 100% after ILP with TNF and melphalan. TNF/melphalan isolated limb reperfusion was found to be more effective in terms of CR after initial ILP regimens that did not utilize melphalan (100% CR after nonmelphalan ILP vs. 50% CR after melphalan ILP [P = 0.04]). Regional toxicity was comprised of mild skin blistering and peeling in 47% of patients. One patient developed Grade 3 (based on National Cancer Institute Common Toxicity Criteria) skin necrosis, and one developed Grade 5 muscle and nerve toxicity, requiring an amputation. CONCLUSIONS: Isolated limb reperfusion with TNF and melphalan can be performed safely with response rates similar to those of other trials of single perfusions. Repeat ILP using TNF and melphalan in patients with melanoma who have failed prior ILP with chemotherapeutics is justified. The utility of TNF (vs. melphalan alone) will be defined in ongoing Phase III trials.     

Isolated limb infusion with cytotoxic agents: a simple alternative to isolated limb perfusion

We use population genetics theory and computer simulations to demonstrate that population bottlenecks cause a characteristic mode-shift distortion in the distribution of allele frequencies at selectively neutral loci. Bottlenecks cause alleles at low frequency (< 0.1) to become less abundant than alleles in one or more intermediate allele frequency class (e.g., 0.1-0.2). This distortion is transient and likely to be detectable for only a few dozen generations. Consequently only recent bottlenecks are likely to be detected by tests for distortions in distributions of allele frequencies. We illustrate and evaluate a qualitative graphical method for detecting a bottleneck-induced distortion of allele frequency distributions. The simple novel method requires no information on historical population sizes or levels of genetic variation; it requires only samples of 5 to 20 polymorphic loci and approximately 30 individuals. The graphical method often differentiates between empirical datasets from bottlenecked and nonbottlenecked natural populations. Computer simulations show that the graphical method is likely (P > .80) to detect an allele frequency distortion after a bottleneck of < or = 20 breeding individuals when 8 to 10 polymorphic microsatellite loci are analyzed.     

Kinetics of circulating TNF-alpha and TNF soluble receptors following surgery in a clinical model of sepsis

The interrelationship between cytokines and their natural antagonists in patients with systemic sepsis are incompletely understood. We have followed the changes in serum levels of TNF-alpha and the two soluble receptors (TNF-sr) in a clinical model of post-operative sepsis. Serial blood samples were taken in patients undergoing percutaneous nephrolithotomy (PCNL) starting pre-operatively and continuing for 24 h thereafter. The levels of TNF-alpha and TNF-sr were raised in patients who became clinically septic and correlated well with the severity of sepsis (using the APACHE III score). In septic patients there was no difference in the pattern of changes in the two types of receptor (TNF-sr55 and TNF-sr75). However, in non-septic patients TNF-sr75 was higher in those with endotoxaemia than those without. This difference was not observed with TNF-sr55 which suggests a different mechanism of release or degree of sensitivity for the two soluble receptors. Regardless of severity of illness, the levels of all three molecules (TNF-alpha and the two receptors) appeared to start rising at about the same time point. The peak TNF-alpha level was reached earlier (2-4 h) than that of the two TNF-sr (4-8 h). The relative rise in TNF-alpha was greater than that of the soluble receptors and this difference was even more marked in those with more severe sepsis. The relationship between peak TNF-alpha and peak TNF-sr was non-linear and the concentration of each TNF-sr appeared to plateau at the higher levels of TNF-alpha. This suggests the exhaustion of a limited pool or saturation of the rate of release. Taken together, these results suggest sepsis develops because of delayed and insufficient secretion of TNF-sr compared with TNF-alpha.     

Plasma patterns of tumor necrosis factor-alpha (TNF) and TNF soluble receptors during acute meningococcal infections and the effect of plasma exchange

In 39 patients with acute meningococcal infections, the plasma concentrations of tumor necrosis factor-alpha (TNF) and its soluble receptors (sRs) TNFsR-p55 and TNFsR-p75 were measured from admission till recovery. At admission, patients with shock had significantly higher TNF, TNFsR-p55, and TNFsR-p75 values than patients without shock. In addition, during the first 24 hours, patients with shock had higher TNFsR-p75 to TNFsR-p55 ratios, indicating that in shock the increase of TNFsR-p75 exceeds that of TNFsR-p55. TNF measured more than 12 hours after admission failed to differentiate between shock and nonshock because TNF concentrations normalized within 12-24 hours. However, because concentrations of TNFsRs remained elevated for 5-6 days, at that time plasma TNFsRs still differentiated between shock and nonshock. Plasma exchange or whole blood exchange (PEBE), performed in 20 patients with shock, accelerated the decrease of plasma TNFsRs. However, because of a rebound after each PEBE session, the overall half-lives of both TNFsRs were not affected by PEBE.     

Gene transfer into nerve and muscle by isolated limb perfusion or during replantation

In this study, the authors tested the feasibility of adenovirus vectors transferring functional genetic material into relevent soft-tissue structures during replantation of mouse hindlimbs. An adenovirus vector was constructed encoding the marker gene LacZ and CMV promoter and titered by plaque forming assay to 5 x 10(9) particles/ml. C3H mouse hindlimbs were divided into three groups. In Group 1 (n = 9), the femoral neurovascular bundle was divided and re-anastomosed . Group 2 (n = 9) hindlimbs were transected at mid-femur, perfused with adenovirus, and replanted. Group 3 limbs (n = 4) were perfused with saline only, followed by replantation. After 48 hr, morbidity and mortality were assessed, and the replanted limbs were assayed for gene transfer by histochemistry and polymerase chain reaction. 12/18 limbs were viable after 48 hr. Histochemical staining for adenovirus-mediated LacZ expression was positive within skeletal muscle, femoral nerve, and capillaries adjacent to the anastomoses. Distal muscle was also gene transfer positive. PCR analysis confirmed adenovirus-mediated gene transfer within the femoral nerve and skeletal muscle. This study confirms that viral-mediated gene transfer can be accomplished into the soft tissues of a replanted extremity.     

Expression of TNF and the necessity of TNF receptors in bleomycin-induced lung injury in mice

Bleomycin (BLM) induction of lung fibrosis in mice is an established model to study the mechanism of pulmonary fibrosis. Cytokine secretion has been implicated as a fundamental component of the lung fibrotic process observed in response to BLM. Among the cytokines implicated in lung fibrosis, Tumor necrosis factor (TNF) alpha has been considered to play a fundamental role. In the present study, we characterized the cellular sources of TNF during BLM-induced lung injury and examined the importance of TNF receptors in this process. To characterize the expression of TNF, we utilized two strains of mice, one sensitive (C57BL/6) and one resistant (BALB/c) to BLM-induced lung injury. Mice received BLM (120 mg/kg total) or saline, as control, by multiple subcutaneous injections. BLM induced the development of inflammation in subpleural areas only in the lungs of BLM-sensitive mice. These subpleural areas were characterized by infiltration of CD68-positive macrophages and increased collagen deposition. BLM enhanced the expression of TNF mRNA in BLM-sensitive, but not in BLM-resistant, mice. In situ hybridization studies localized the expression of TNF in the areas of BLM-induced inflammation in 6% and 27% of macrophages at 14 and 21 days post BLM treatment. In addition to TNF, BLM exposure resulted in the upregulated expression of transforming growth factor (TGF)-beta 1, but not interleukin (IL)-1, mRNA in the lungs of both murine strains at 14 and 21 days. This upregulated expression of TGF-beta 1 mRNA was greater in the lungs of BLM-sensitive mice. In separate experiments, double TNF receptor knockout mice were exposed to BLM. These animals demonstrated an increased expression of TNF, but not TGF-beta 1, mRNA in response to BLM and did not exhibit histologic evidence of lung injury following BLM exposure. In summary, the upregulation of TNF mRNA in macrophages correlated with the appearance of inflammation following BLM exposure and was limited to the BLM-sensitive strain. Furthermore, in addition to the release of the TNF ligand, it appears that the presence of TNF receptors is necessary for the development of BLM-induced lung injury, and signaling through these receptors may contribute to the regulation of the TGF-beta 1 mRNA expression observed in response to bleomycin. These results provide further support for a role of macrophages and TNF in the induction of lung inflammation.     

Differences in the shedding of soluble TNF receptors between endotoxin-sensitive and endotoxin-resistant mice in response to lipopolysaccharide or live bacterial challenge

TNF-alpha plays a pivotal role in the pathogenesis of septic shock. It exerts its effects by binding two cell surface receptors, designated TNF-R I and II, also referred to as the p55 and p75 receptors, respectively. TNF-Rs are transmembrane proteins, which on cleavage of their extracellular domains, result in the release of soluble fragments (sTNF-R). sTNF-R levels increase markedly during infection, and may serve to modulate TNF-alpha bioactivity. The mechanisms regulating this process are uncertain. To investigate this, we measured sTNF-R release in endotoxin-sensitive C3H/HeN and endotoxin-resistant C3H/HeJ mice given LPS or live Gram-negative bacteria. In C3H/HeN mice, there was a rapid early response during the first 4 h, and a second peak at 8 h, particularly noticeable in the case of the p75 receptor. Prior administration of neutralizing Abs to TNF-alpha or IFN-gamma had no effect on receptor shedding. Surprisingly, C3H/HeJ mice also responded to both bacterial challenge and to LPS by shedding sTNF-R; the magnitude and duration of the early response was not substantially different from C3H/HeN mice, although the second peak was absent. Peritoneal macrophages from C3H/HeN mice responded promptly (5 h) when stimulated with LPS in vitro, and by 22 h levels had increased five- to 10-fold. In contrast, cells from C3H/HeJ mice demonstrated only a very modest response at 22 h following maximal stimulation. The data suggest that there may be at least two separately regulated pathways that control sTNF-R shedding in these mice.     

Synergistic antitumour effect of recombinant human tumour necrosis factor alpha with melphalan in isolated limb perfusion in the rat

The efficacy of isolated limb perfusion (ILP) for 'intransit' metastases from malignant melanoma and irresectable soft tissue sarcoma has been improved considerably by the addition of tumour necrosis factor (TNF) alpha. A rat sarcoma tumour model was, therefore, developed to evaluate the effects of TNF-alpha, melphalan and the combination of these drugs in the treatment of sarcoma. In BN rats bearing the non-immunogenic BN 175 sarcoma ILPs were performed with perfusate only, TNF-alpha, melphalan alone, or in combination when tumours had grown to approximately 1.5 cm in diameter. All rats treated with sham perfusion or perfusion with 50 micrograms TNF-alpha showed progressive disease. After perfusion with 40 micrograms melphalan no change in tumour diameter was observed in any rats at 4 days. After a combined perfusion with 40 micrograms melphalan and 50 micrograms TNF-alpha complete remission was noted in 12 of 16 rats. This synergistic effect in vivo between relatively ineffective doses of TNF-alpha and melphalan was not observed in vitro.     

Neuroleptic treatment increases soluble IL-2 receptors and decreases soluble IL-6 receptors in schizophrenia

The cytokines interleukin-2 (IL-2) and interleukin-6 (IL-6) increase during immune activation, they are released from activated astrocytes and microglial cells in the central nervous system (CNS), and they are able to enhance the catecholaminergic neurotransmission. This study focused on the soluble receptors of IL-2 and IL-6 (sIL-2R, sIL-6R) as a part of the regulation system of IL-2 and IL-6. We studied serum levels of sIL-2R in 30 schizophrenic patients not under neuroleptic medication during an acute exacerbation of the disease and reexamined these patients under neuroleptic treatment after clinical improvement. The sIL-6R levels of 39 schizophrenic patients were estimated under the same conditions. The results were compared with the levels of sIL-2R and sIL-6R in 42 healthy controls. No difference was found between the schizophrenic patients before neuroleptic treatment and the healthy controls. During neuroleptic treatment, however, there was a significant increase of sIL-2R levels and a significant decrease of the sIL-6R levels between the pre- and post-conditions. In comparison with healthy controls, the treatment group also showed increased sIL-2R levels and decreased sIL-6R levels. These results suggest that treatment with neuroleptics is associated with increased sIL-2R and decreased sIL-6R. Since sIL-2R bind and inactivate IL-2, whereas sIL-6R form an active complex with IL-6, the increase of sIL-2R and the decrease of sIL-6R together may reflect a functional down regulation of these activating cytokines. This suggests that neuroleptic therapy has a differentiated immunomodulatory effect.     

Thrombolytic therapy in an isolated limb

Intraoperative thrombolytic therapy is a useful adjunct to balloon catheter thromboembolectomy for treatment of acute embolism or thrombosis, but the technique is frequently limited by incomplete thrombolysis and systemic hemorrhage. In an attempt to improve results and reduce complications of conventional thrombolytic therapy, urokinase was infused into a limb that was isolated with a tourniquet. This isolated limb perfusion technique was initially developed in an animal model and subsequently used for limb salvage in patients who failed thromboembolectomy. The animal model demonstrated that a fibrinolytic state could be achieved and isolated to the extremity, even when using extremely high dose (20,000 to 50,000 IU/kg) of thrombolytic agents. The fibrinogen level was unmeasurable and the prothrombin, partial thromboplastin, and thrombin times were significantly prolonged in the isolated limb (p < 0.001), whereas no changes occurred in these parameters in the systemic circulation. In seven patients, streptokinase (27,000 to 200,000 IU) and urokinase (150,000 to 300,000 IU) were infused into isolated extremities after thrombectomy alone had failed to restore blood flow. All extremities showed improved perfusion after thrombolytic therapy and five remained viable 6 months after treatment. There were no systemic bleeding complications despite two patients having undergone major operations within 6 days. Tourniquet isolation of the limb can achieve extremely high concentrations of thrombolytic drugs while reducing the potential for systemic fibrinolysis and allows lysis of previously inaccessible thrombus.     

Neutrophil Fc gamma and complement receptors involved in binding soluble IgG immune complexes and in specific granule release induced by soluble IgG immune complexes

We examined the effect of soluble IgG immune complex (IC) characteristics on the binding of IC to human neutrophils and IC-induced specific granule release of neutrophils via Fc gamma receptors (CD16 and CD32) and complement receptors (CR1 and CR3). A set of soluble IgG IC varying in size, IgG subclass, antigen epitope density and complement (C) incorporation were formed between 5-iodo-4-hydroxy-3-nitrophenacetyl (NIP) coupled to bovine serum albumin (BSA) and chimeric mouse-human anti-NIP monoclonal antibodies (mAb) of all four IgG subclasses. High and low epitope density IC of all four IgG subclasses induced specific granule release with C, but in the absence of C only IgG1 and IgG3 IC were functionally active. The Fc gamma and C receptors responsible for IgG IC-induced specific granule release and IC binding were determined using mAb specific for the ligand binding sites of CD16, CD32 and CR3, and recombinant soluble CR1. Each defined IC displayed a unique pattern of receptor preference, dependent upon subclass and antigenic epitope density. IC binding and IC-induced specific granule release was not mediated by the same receptor, or combination of receptors. High and low epitope density IgG3 IC binding and induction of specific granule release was mediated predominantly via CD16. Other IC subclasses bound differently, i.e. IgG1 IC used CD16 and CR3; IgG2 and IgG4 predominantly used complement receptors; but all three induced specific granule release via CD32. In vivo these results may translate into differential activation of neutrophils by soluble IC dependent upon their characteristics, leading to subtle nuances in the etiology, pathology and control of the immune response in IC-related diseases.     

Control of Leishmania major infection in mice lacking TNF receptors

TNF participates in the induction of nitric oxide (NO) production and macrophage activation, leading to the elimination of intracellular pathogens. We previously found that TNF receptor p55-deficient mice (TNFRp55-/-) control replication of Leishmania major in vivo but fail to resolve their lesions. Here we report that mice lacking the p75 receptor (TNFRp75-/-) or both receptors (TNFRp55p75-/-), also control parasite replication, albeit mice lacking the p55 receptor (either TNFRp55-/- or TNFRp55p75-/-) are delayed in their elimination of L. major compared with controls. All TNF receptor-deficient mice developed a Thl-type immune response and up-regulated inducible NO synthase (iNOS) mRNA gene expression in lesions during infection. Thus, neither TNF receptor appears to be absolutely required for NO production or elimination of L. major in vivo. In vitro, however, while macrophages from naive TNFRp75-/- mice could be activated to produce NO and kill L. major, we observed a defect in NO production and parasite killing by resident peritoneal macrophages from naive TNFRp55-/- or TNFRp55p75-/- mice. However, when macrophages were elicited with leishmanial Ag from 4-wk-infected TNFRp55-/- or TNFRp55p75-/- mice, they produced NO and were leishmanicidal. These data suggest that the TNFRp75 plays no essential role in L. major infection in mice and that the p55 receptor may be required for optimal macrophage activation. However, the results also show that a mechanism exists by which macrophages can be primed in vivo during L. major infection to produce NO and kill L. major in the absence of signaling through either of the TNF receptors.     

PET evaluation of therapeutic limb perfusion in Merkel's cell carcinoma

An 87-yr-old woman diagnosed with recurrent Merkel's cell carcinoma was treated with therapeutic limb perfusion and underwent PET scanning with 18F-fluorodeoxyglucose (FDG). PET studies were obtained before and after treatment to determine the response to the intervention. A baseline whole-body study was obtained to assess the extent and degree of disease activity. This was followed by a repeat PET scan 2 mo. later after treatment with isolated limb chemotherapy with high-dose melphalan and tumor necrosis factor-alpha. The initial scan demonstrated multiple foci of high FDG uptake in the left calf, a left supraclavicular lesion and also detected concurrent keratinizing squamous cell metastasis in the right axilla. A repeat PET study showed complete metabolic resolution of the lesions in the left calf after treatment. FDG PET may be a useful technique for staging Merkel cell carcinoma and for assessing the tumor response after therapy of this rare tumor.     

Effects of isolated limb perfusion with tumour necrosis factor-alpha on the function of monocytes and T lymphocytes in patients with cancer

The objective of the present study was to investigate the effects of isolated limb perfusion (ILP) with tumour necrosis factor alpha (TNF-alpha) and melphalan in patients with cancer on, first, plasma levels of cytokines, second, systemic monocyte and T-lymphocyte distribution and, third, the ability of mononuclear cells to produce cytokines upon stimulation in vitro. Six patients undergoing an ILP were entered into the study (group 1). In addition, patients undergoing a major surgical operation (group 2) minor operation (group 3) as well as healthy volunteers (group 4) were included as control groups. Sensitive enzyme-linked immunosorbent assays (ELISAs) were used to measure TNF-alpha and interleukin-6 (IL-6) plasma levels at various time points during and after operation. Furthermore, the percentage of monocytes and T lymphocytes was determined in all studied groups using a FACScan. In addition, cytokine production upon stimulation with lipopolysaccharide (LPS) and a combination of anti-CD3/anti-CD28 monoclonal antibodies in whole-blood cultures was investigated. Increased plasma levels of TNF-alpha and IL-6 in patients undergoing ILP was observed, but only IL-6 appeared to be increased in patients treated with a major operation. No significant fluctuations were found in the other groups studied. Concerning the number of monocytes, a significant decrease was observed only in patients treated with ILP. Furthermore, a decreased production of TNF-alpha, IL-6 and IL-8 upon various types of stimulation in vitro was found in those patients, but also after a major operation. In conclusion, the results of the present study show increased plasma levels of cytokines in patients treated with ILP and major operation. Furthermore, a decrease in numbers of monocytes in the circulation and the ability of mononuclear cells to produce cytokines in vitro may be induced by administration of TNF-alpha in ILP. Although similar results were found in patients treated with major operation, the underlying mechanisms of this phenomenon remain to be elucidated.