Case of crural ulcer during polycythemia vera

A case of polycythaemia vera, in which a crural ulcer appeared numerous years after the onset of the disease, is reported. The absence of important angioneurological lesions and the signs at cutaneous lesion level of capillary dilatation, suggest that crural ulcer is a complication of polycythaemia. Aetiopathogenetic aspects are also discussed.     

Prophylactic perioperative treatment in a patient with colon carcinoma complicated by polycythemia vera

A patient with colon carcinoma complicated by polycythemia vera (PV) who underwent a partial colectomy concomitant with prophylactic perioperative treatment resulting in successful outcome is herein described. Seven weeks after the cessation of the latest exacerbation of PV, a partial colectomy was performed. In order to prevent the development of disseminated intravascular coagulation and thrombotic complications, the following perioperative treatment was performed: administration of gabexate mesilate (2,000 mg/day), fresh frozen plasma (300 ml/day), heparin (5,000 IU/day) for 7 days and anti-thrombin-III for 4 days, and a potent antibiotic therapy for 12 days and graded elastic bandages around the bilateral lower extremities for 14 days. As a result, an uneventful postoperative course was achieved. The present case suggests that these treatments are useful in the perioperative management of PV patients.     

Hemorheologic considerations in the pathogenesis of vascular occlusive events in polycythemia vera

Polycythemia vera (PV) commonly presents with vascular occlusion. Untreated patients have a poor prognosis due to the occurrence of thromboses. Treatment outcomes in PV and thrombotic events in other forms of polycythemia and in primary thrombocythemia lead to the conclusion that both raised packed cell volume (PCV) values and quantitative/qualitative platelet changes play a role in the pathogenesis of these vascular occlusive events. In vitro blood viscosity values are predominantly affected by the PCV, particularly at low shear rates and are thus high in untreated PV. Generally, under physiologic conditions blood flow is not governed by blood viscosity due to a number of factors, such as prevailing high shear rates, red cell axial migration, and adaptive vessel diameter changes. Peripheral blood flow is low in untreated PV. Whereas some untreated patients maintain adequate oxygen transport to the tissues, this may not apply in those with cardiac or local vessel disease. There is evidence that low flow rates predispose to occlusive events. Under pathologic low blood flow or static conditions, the rheologic blood changes of untreated PV, demonstrated in vitro, play a role in producing a more deleterious outcome of an occlusive event. Under blood flow conditions, red cell axial migration occurs. This leaves a plasmatic zone at the vessel wall into which platelets are dispersed and where shearing forces are maximal. These forces lead to platelet activation. Increased PCV values reduce the width of the plasmatic zone and lead to an increased possibility of platelet activation, platelet-platelet contact and platelet-vessel wall interaction, particularly when the platelet count is raised as well. These effects increase the likelihood of the initiation of thrombus formation in PV.     

Risk factors and prevention of vascular complications in polycythemia vera

Two experiments investigated long-term verbal memory performance in groups of 20-year-old heavy (HSDs) and light social drinkers (LSDs), in the presence and absence of a pharmacological challenge (lorazepam 2 mg). In Experiment 1 (n = 13), a verbal learning task was presented visually and it was found that lorazepam significantly impaired delayed verbal recall performance in both groups. Experiment 2 (n = 14) assessed the effect of presenting the verbal learning task in the auditory compared to the visual modality. Both groups' performance on the delayed trials of the visually presented task was reduced in the lorazepam treatment. However, in the auditory presented task, lorazepam reduced 30-min delayed recall performance in the HSDs but not in the LSDs. The differential effect of lorazepam on HSDs compared to LSDs on delayed recall performance when material is presented in the auditory modality may suggest that frequent heavy social drinking results in changes in CNS functioning.     

Retinopathy secondary to anemia from myeloid metaplasia in polycythemia vera

The cutaneous vasculature is a dynamic network that responds to its environment depending upon specific demands in time and space. Changes in its functional role can be observed as changes in gross structure, or by alterations in specific gene expression or function. The improved understanding in mechanisms by which EC participate in inflammatory, neoplastic, and reparative processes will likely reap great benefits in our understanding and treatment of cutaneous disease.     

The present state of pathophysiology and therapeutic trials in polycythemia vera

Polycythemia vera shares basic features of pathogenesis with other subtypes of the group of chronic myeloproliferative disorders. All myelopoietic cells are derived from one transformed hemopoietic stem cell. Genetic instability of mitotic clonal cells explains the risk of leukemic transformation, which may be enhanced by cytoreductive treatment. Recent data show that erythroid hyperplasia is not due to erythropoietin hypersensitivity, but rather to abnormal stimulation by other cytokine growth factors. Treatment as established by clinical trials has almost normalized life expectancy in older patients, but the optimal strategy for subgroups of patients is still unknown. For younger patients, new and potentially curative approaches should be investigated.     

Essential thrombocythemia following polycythemia vera: an unusual sequence

Myeloproliferative disorders (MPD) are prone to modification and evolution during the progression of the disease. While post-polycythemia myeloid metaplasia and chronic myelogenous leukemia following polycythemia vera have been frequently described, no report is available about the evolution of polycythemia vera into essential thrombocythemia. Our case is probably the first report on this occurrence. In the course of a fortuitous observation of electrocardiographic alterations, a diagnosis of polycythemia vera was ruled out in accordance with polycythemia vera study group criteria. At the time of diagnosis, RBC was 6 x 10(12)/L, WBC 15 x 10(9)/L, Ht 59% and platelets 1000 x 10(9)/L. The patient was treated with phlebotomies and radioactive phosphorus achieving a good remission or the disease. Five years later, platelets rose to over 3300 x 10(9)/L without significant modification or RBC, WBC and Ht. The restaging or the disease was consistent for an essential thrombocythemia. In particular, RBC mass was within normal levels. During the last ten years, the patient has been followed recurrently and the blood picture remained stationary, without an increase in the hematocrit but with a platelet count between 658 and 800 x 10(9)/L. We conclude that this report may complete data concerning the evolution of MPD in others.     

Spinal cord compression by spontaneous spinal subdural haematoma in polycythemia vera

A woman with an eight-year history of polycythemia vera presented with numbness and weakness of both legs. A large spinal haematoma was revealed on magnetic resonance imaging which was treated clinically and which subsequently resolved.     

A case of dilated cardiomyopathy caused by myocardial microinfarcts in the course of polycythemia vera

This article presents a case of 45-year-old man with polycythemia vera non diagnosed before. The first symptom of polycythemia vera was acute congestive heart failure which suggested diagnosis of myocarditis. Polycythemia vera was confirmed by raised hematocrit, significantly increased platelet count, normal oxygen saturation, score for leukocyte alkaline phosphatase (LAP)-130 and splemomegaly. Echocardiography revealed left ventricular histological. Coronary arteriography showed normal coronary arteries. Finding of histological examination of the endomyocardial biopsy were described as necrosis of myocytes and abnormal blood flow in very small coronary vessels. It was the main reason of dilated cardiomyopathy caused by microinfarcts in polycythemia vera. Hematological parameters were reduced to normal levels after hydroxyurea treatment. Digitalis and ACE-inhibitor therapy quickly improved cardiovascular status from III to II NYHA class.     

Interleukin-10 inhibits erythropoietin-independent growth of erythroid bursts in patients with polycythemia vera

In polycythemia vera (PV) erythroid colonies that grow in vitro in the absence of exogenous erythropoietin (EPO) arise from the abnormal clone that is responsible for overproduction of red blood cells. Although the mechanism of autonomous formation of burst-forming units-erythroid (BFU-E) is not fully understood, a spontaneous release of growth regulatory molecules by PV cells and/or by accessory cells is likely to be involved. Because of its cytokine synthesis inhibiting action, interleukin-10 (IL-10) could be a potentially useful molecule to modulate abnormal erythropoiesis in PV. We studied the effect of recombinant human IL-10 on the EPO-independent growth of erythroid bursts derived from peripheral blood mononuclear cells (PBMNCs) of patients with PV. IL-10 showed a profound, dose-dependent, and specific inhibitory effect on autonomous BFU-E formation. Ten nanograms per milliliter of IL-10 significantly suppressed spontaneous growth of erythroid colonies in methylcellulose in five of five PV patients tested with a mean inhibition by 81% (range, 72-94). To elucidate the possible mechanism of the inhibitory action of IL-10 we further studied the effect of anticytokine antibodies on autonomous BFU-E growth and the ability of exogenous cytokines to restore IL-10-induced suppression of erythroid colony growth. Among a panel of growth regulatory factors tested (granulocyte-macrophage colony-stimulating factor [GM-CSF], IL-3, granulocyte colony-stimulating factor, stem cell factor, and insulin-like growth factor-1) GM-CSF was the only molecule for which both an inhibition of spontaneous BFU-E formation by its respective antibody as well as a significant restimulation of erythroid colonies in IL-10-treated cultures by exogenous addition was found. Moreover, inhibition of GM-CSF production by IL-10 was shown in PV PBMNCs at the mRNA level. Our data indicate that autonomous BFU-E growth in PV can be profoundly inhibited by IL-10 and that this inhibitory effect seems to be at least in part secondary to suppression of endogenous GM-CSF production.     

A case of myelofibrosis that developed polycythemia vera following treatment with ranimustine and then acute myelogenous leukemia (M0)

Short latency somatosensory evoked potentials (SSEP) to median nerve stimulation recorded from post-Rolandic area and the surface of processus spinosus of Cvs at the same record time. To assess electrophysiologically functional status of central nervous system (CNS), SSEP were studied in 43 patients with ischemic heart disease (IHD); 18 cases of angina pectoris (AP group), 25 cases of old myocardial infarction (MI group), and 14 non-IHD controls (NC group). The N13, N20, P25 peak latencies (PLs) and the central conduction time (CCT, the peak latency between N13 and N20) in AP group or MI group were prolonged remarkably compared with NC group. Likewise, MI group showed significant prolongation of N20, P25 PLs and CCT compared to the AP group. Furthermore, in MI group, the N20 peak amplitude was significantly lowered; the subjects percentages of the N20 or P25 amplitude detraction more than 40 percent in one side and the P25 interextremital latency difference over 1 ms were significantly increased than those of the NC group. These results suggested the pathological changes of the somatosensory pathway from superior spinal cord or medulla oblongata to cerebral cortex primary sensory area in CNS in the IHD patients.     

Impaired platelet binding of fibrinogen due to a lower number of GPIIB/IIIA receptors in polycythemia vera

We have previously described a stimulus-specific defect in platelet aggregation in polycythaemia vera (PV) after stimulation with surface receptor dependent agonists such as platelet activating factor (PAF). In contrast, responses to phorbol myristate acetate (PMA) were normal. We now report that after PAF stimulation, using flow cytometry, the amount of fibrinogen bound to its receptor was significantly lower in PV platelets with a median MFI of 6.0 (range 4.1-17.3) compared to controls, 12.8 (range 8-21.3; n=11; p<0.01). We found no evidence of preactivation of PV platelets. Quantitative analysis of GPIIIa gave a significantly lower number of GPIIIa on resting PV platelets, 14300 subunits of GPIIIa (range 8500-15500) vs. 19800 for controls (range 13400-26800; n=12; p<0.01). Both patients and controls increased their number of receptors on the cell surface after stimulation with PAF and PMA, but the significant difference in the number of receptors per cell remained. Indirect evaluation of PAF receptor function showed that activation of CD 62 did not differ in PV and controls after PAF stimulation. Additionally, although the basal level of serotonin in platelet-rich plasma was significantly lower in PV, there was a threefold increase of the basal level after stimulation with PAF for both PV and control platelets, also indicating a normal interaction of PAF with its receptor. Although our results indicate both an impaired PAF induced aggregation in PV and a lower number of GPIIb/IIIa complexes on single platelets, whether these phenomena are related remains uncertain.