Renal transplantation in adults with thrombotic thrombocytopenic purpura/haemolytic-uraemic syndrome

BACKGROUND: Thrombotic thrombocytopenic purpura/haemolytic-uraemic syndrome (TTP/HUS) is a rare cause of renal failure in adults. There is little data concerning the outcome of adult patients who receive a renal transplant for TTP/HUS: METHODS: We have carried out a survey of 22 transplant centres in the USA to determine the outcome of patients who developed ESRD from TTP/HUS and latter received a renal transplant. RESULTS: Twelve of the 22 centres responded to our inquiry. Seven centres had not transplanted any patients with TTP/HUS, and five centres had transplanted a total of 24 grafts in 17 patients with TTP/HUS: Thirty-three per cent of patients demonstrated definite clinical and pathological evidence of recurrence of TTP/HUS: An additional 16% of patients demonstrated pathological evidence of possible recurrence of TTP/HUS in the absence of clinical manifestations. The overall 1-year graft survival rate was 42% and the 2-year graft survival rate was 35%. In our experience recurrence TTP/HUS was associated with universal graft failure. Although cyclosporin A does occasionally cause a thrombotic angiopathy in patients with no history of TTP/HUS, we found no evidence that it should be avoided in patients with a previous history of ESRD from TTP/HUS who subsequently receive a renal transplant. CONCLUSIONS: TTP/HUS frequently recurres in adults who receive a renal transplant, with a 2-year graft survival rate of 35%.     

Increased serum levels of thrombopoietin in patients with thrombotic thrombocytopenic purpura, idiopathic thrombocytopenic purpura, or disseminated intravascular coagulation

The serum levels of thrombopoietin (TPO) were measured in 16 patients with thrombotic thrombocytopenic purpura (TTP), 12 with hemolytic uremic syndrome (HUS), 10 with aplastic anemia (AA), 10 with disseminated intravascular coagulation (DIC), and 71 with idiopathic thrombocytopenic purpura (ITP). The serum TPO levels were measured with a sensitive sandwich enzyme-linked immunosorbent assay. The serum TPO level in the ITP group (1.68 +/- 0.85 fmol/ml) were not significantly increased compared with those of the normal subjects. The TPO levels in the TTP (2.77 +/- 1.38 fmol/ml) and HUS groups (5.77 +/- 4.41 fmol/ml) were higher than those of the normal subjects. The patients with AA (12.7 +/- 8.0 fmol/ml) and those with DIC (13.3 +/- 5.7 mol/ml) had significantly higher serum TPO levels than did the normal subjects and ITP patients. The TPO levels were well correlated with the platelet counts in the TTP patients, and were negatively correlated with the platelet counts in the ITP patients. These results suggest that the serum TPO levels in some thrombocytopenic diseases are regulated not only by the platelet count and the megakaryocyte mass, but also by other factors.     

Laboratory abnormalities in thrombotic thrombocytopenic purpura. Canadian Apheresis Group

Thrombotic thrombocytopenic purpura is an uncommon disorder that requires prompt recognition and intervention to prevent death. To date, information regarding the classic laboratory abnormalities in the disease has been derived from small numbers of patients whose laboratory tests have been done at many different sites. We report the laboratory findings in 135 patients who presented with thrombotic thrombocytopenic purpura to 17 Canadian centres. 50 men and 85 women had a mean platelet count of 25.3+/-19.4x10(9)/l. The initial platelet count correlated with mortality; 32% of patients with a platelet count of 20x10(9)/l or less died compared with 18% of patients with a platelet count >20x10(9)/l (P=0.058). The platelet-associated IgG was elevated in 88% at presentation whereas the indirect platelet suspension immunofluorescence test was positive in only 18%, 93% of the sera showed reactivity against platelets following protein blotting. All sera tested also showed reactivity against endothelial cells. Immune complexes were seen in all patients, whereas the platelet aggregating factor was detected in 59%. Although the von Willebrand factor was elevated in the majority of patients at entry, the multimer pattern was variable and showed no predictive pattern. Renal dysfunction was common (18%).     

Cytokines in childhood hemolytic uremic syndrome and thrombotic thrombocytopenic purpura

Serum and urine cytokines were analyzed in children with hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). Interleukin-6 (IL-6) was elevated in the serum of 33 of 35 children with HUS (94%) and in 2 of 2 children with recurrent TTP. Serum IL-6 was higher in children with HUS who developed anuria, extrarenal manifestations during the acute phase of illness and/or chronic renal sequelae. Tumor necrosis factor-alpha (TNF-alpha) was detected in the serum of 7 patients with HUS (20%) and 1 patient with TTP. IL-6 and TNF-alpha were elevated in the urine of 4 of 4 children with HUS and 2 of 2 children with TTP. Urinary levels were higher than serum levels, suggesting local production of cytokines in the urinary tract. Sequential serum and urine samples showed that IL-6 levels varied with disease activity. IL-6 and TNF-alpha were not detected in the serum (n = 25) and urine (n = 15) of healthy children. We conclude that IL-6 in urine may be used to monitor disease activity in HUS and TTP.     

Enhanced endothelial cell apoptosis in splenic tissues of patients with thrombotic thrombocytopenic purpura

Idiopathic thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy of obscure etiology. The fundamental pathologic lesion is a hyaline thrombus composed of platelets and some fibrin accompanied by endothelial cell proliferation and detachment, in the absence of an inflammatory response. We have previously demonstrated that plasmas from patients with both idiopathic TTP and a related disorder, sporadic hemolytic-uremic syndrome (HUS), induce apoptosis and expression of the apoptosis-associated molecule Fas (CD95) in vitro in those lineages of microvascular endothelial cells (MVECs) that are affected pathologically. We now demonstrate the presence of enhanced MVEC apoptosis in splenic tissues from patients with TTP, documented by terminal deoxynucleotidyl-transferase-mediated dUTP nick-end labeling (TUNEL) and morphology. This is accompanied by elevated Fas expression. It contrasts with the absence of apoptosis in splenic tissues obtained after splenectomy for trauma or immune thrombocytopenic purpura. TUNEL-positive cells, identified by immunohistochemistry as MVECs or macrophages, presumably engulfing apoptotic ECs, are noted in numerous areas, including those apart from microthrombi. Thus, it is unlikely that EC apoptosis is simply a sequela of thrombus formation. Based on these data, we propose that MVEC apoptosis is of pathophysiologic significance in idiopathic TTP/sporadic HUS.     

Antibodies to von Willebrand factor-cleaving protease in acute thrombotic thrombocytopenic purpura

BACKGROUND: Thrombotic thrombocytopenic purpura is a potentially fatal disease characterized by widespread platelet thrombi in the microcirculation. In the normal circulation, von Willebrand factor is cleaved by a plasma protease. We explored the hypothesis that a deficiency of this protease predisposes patients with thrombotic thrombocytopenic purpura to platelet thrombosis. METHODS: We studied the activity of von Willebrand factor-cleaving protease and sought inhibitors of this protease in plasma from patients with acute thrombotic thrombocytopenic purpura, patients with other diseases, and normal control subjects. We also investigated the effect of shear stress on the ristocetin cofactor activity of purified von Willebrand factor in the cryosupernatant fraction of the plasma samples. RESULTS: Thirty-nine samples of plasma from 37 patients with acute thrombotic thrombocytopenic purpura had severe deficiency of von Willebrand factor-cleaving protease. No deficiency was detected in 16 samples of plasma from patients with thrombotic thrombocytopenic purpura in remission or in 74 plasma samples from normal subjects, randomly selected hospitalized patients or outpatients, or patients with hemolysis, thrombocytopenia, or thrombosis from other causes. Inhibitory activity against the protease was detected in 26 of the 39 plasma samples (67 percent) obtained during the acute phase of the disease. The inhibitors were IgG antibodies. Shear stress increased the ristocetin cofactor activity of von Willebrand factor in the cryosupernatant of plasma samples obtained during the acute phase, but decreased the activity in cryosupernatant of plasma from normal subjects. CONCLUSIONS: Inhibitory antibodies against von Willebrand factor-cleaving protease occur in patients with acute thrombotic thrombocytopenic purpura. A deficiency of this protease is likely to have a critical role in the pathogenesis of platelet thrombosis in this disease.     

Gastric carcinoma and thrombotic thrombocytopenic purpura: association with plasma immune complex concentrations

A patient with metastatic adenocarcinoma of the stomach developed microangiopathic haemolytic anaemia, thrombocytopenia, renal insufficiency, and fluctuating neurological abnormalities in association with appreciably raised plasma concentrations of immune complexes. This syndrome, similar to thrombotic thrombocytopenic purpura, occurred while the tumour was in sustained objective remission after successful treatment with fluorouracil, doxorubicin, and mitomycin. Reversal of the syndrome was achieved with plasmapheresis, azathioprine, corticosteroids, and antiplatelet treatment; this response was paralleled by a reduction in immune complex concentration, suggesting an immune aetiology for the syndrome. Antibodies eluted from the immune complexes reacted with 50% of cells from the gastric cancer but less than 10% of cells from normal gastric mucosa. There was no reactivity with either carcinoembryonic antigen or mitomycin. A 17S immune complex reacted with a glycoprotein from the patient's autologous platelets and produced platelet aggregation. It is postulated that reducing the tumour and the pre-existing state of antigen excess by chemotherapy allowed soluble antigen-antibody complexes to form and the syndrome to develop.     

Coronary artery bypass grafting in immune thrombocytopenic purpura

BACKGROUND: Reports of patients with idiopathic thrombocytopenic purpura undergoing cardiac operations are scarce and no recommendations exist regarding their management. We report 3 patients with idiopathic thrombocytopenic purpura and severe coronary artery disease who underwent uncomplicated coronary bypass grafting. METHODS: The case history of each patient with idiopathic thrombocytopenic purpura who underwent coronary artery bypass grafting and the literature were reviewed. RESULTS: All 3 patients underwent uncomplicated coronary artery bypass grafting after preoperative treatment with intravenous immunoglobulin and intraoperative platelet transfusions if needed. Prophylactic splenectomy was not performed. There was no increased incidence of bleeding complications. CONCLUSIONS: Coronary artery bypass grafting can be safely performed in patients with idiopathic thrombocytopenic purpura using conventional conduits after pretreating with immunoglobulin G and avoiding splenectomy.     

Prostacyclin stability in thrombotic thrombocytopenic purpura. Japan Working Group on TTP

We investigated changes in prostacyclin stabilization activity of the plasma of 13 patients with TTP, by measurement of PGI2 inhibitory activity attenuation on normal platelet aggregation, induced by ADP (4 x 10(-5)M). PGI2 stabilizing activity of plasma was expressed as the half life (half time) in the time course of attenuation of the inhibitory effect of PGI2 on platelet aggregation. The half time was 16.7 +/- 5.8 min in the plasma of 10 healthy subjects. The half time in 10 plasma samples from patients in the acute state of TTP was significantly (p < 0.05) shorter than that of normal plasma. The half time become longer in 8 plasma samples after plasma exchange and increased to normal plasma level, in remission. There was no relationship between the concentration of plasma lipoprotein A1 and the half time of PGI2 stabization activity of plasma.     

von Willebrand factor-cleaving protease in thrombotic thrombocytopenic purpura and the hemolytic-uremic syndrome

BACKGROUND: Thrombotic thrombocytopenic purpura and the hemolytic-uremic syndrome are severe microvascular disorders of platelet clumping with similar signs and symptoms. Unusually large multimers of von Willebrand factor, capable of agglutinating circulating platelets under high shear stress, occur in the two conditions. We investigated the prevalence of von Willebrand factor-cleaving protease deficiency in patients with familial and nonfamilial forms of these disorders. METHODS: Plasma samples were obtained from 53 patients with thrombotic thrombocytopenic purpura or hemolytic-uremic syndrome. Von Willebrand factor-cleaving protease was assayed in diluted plasma samples with purified normal von Willebrand factor as the substrate. The extent of the degradation of von Willebrand factor was assessed by electrophoresis in sodium dodecyl sulfate-agarose gels and immunoblotting. To determine whether an inhibitor of von Willebrand factor-cleaving protease was present, we measured the protease activity in normal plasma after incubation with plasma from the patients. RESULTS: We examined 30 patients with thrombotic thrombocytopenic purpura and 23 patients with the hemolytic-uremic syndrome. Of 24 patients with nonfamilial thrombotic thrombocytopenic purpura, 20 had severe and 4 had moderate protease deficiency during an acute event. An inhibitor found in 20 of these patients was shown to be IgG in five of five tested plasma samples. Of 13 patients with nonfamilial hemolytic-uremic syndrome, 11 had normal levels of activity of von Willebrand factor-cleaving protease during the acute episode, whereas in 2 patients, the activity was slightly decreased. All 6 patients with familial thrombotic thrombocytopenic purpura lacked von Willebrand factor-cleaving protease activity but had no inhibitor, whereas all 10 patients with familial hemolytic-uremic syndrome had normal protease activity. In vitro proteolytic degradation of von Willebrand factor by the protease was studied in 5 patients with familial and 7 patients with nonfamilial hemolytic-uremic syndrome and was normal in all 12 patients. CONCLUSIONS: Nonfamilial thrombotic thrombocytopenic purpura is due to an inhibitor of von Willebrand factor-cleaving protease, whereas the familial form seems to be caused by a constitutional deficiency of the protease. Patients with the hemolyticuremic syndrome do not have a deficiency of von Willebrand factor-cleaving protease or a defect in von Willebrand factor that leads to its resistance to protease.     

Deficient activity of von Willebrand factor-cleaving protease in chronic relapsing thrombotic thrombocytopenic purpura

In patients with thrombotic thrombocytopenic purpura (TTP), excessive intravascular platelet aggregation has been associated with appearance in plasma of unusually large von Willebrand factor (vWF) multimers. These extremely adhesive vWF multimers may arise due to deficiency of a "depolymerase" cleaving vWF to smaller molecular forms, either by reducing the interdimeric disulfide bridges or by proteolytic degradation. We studied the activity of a recently described vWF-cleaving protease in four patients with chronic relapsing TTP. Diluted plasma samples of TTP patients were incubated with purified normal human vWF in the presence of a serine protease inhibitor, at low ionic strength, and in the presence of urea and barium ions. The extent of vWF degradation was assayed by electrophoresis in sodium dodecyl sulfate-agarose gels and immunoblotting. Four patients, that included two brothers, with chronic relapsing TTP displayed either substantially reduced levels or a complete absence of vWF-cleaving protease activity. In none of these patient plasmas was an inhibitor of or an antibody against the vWF-cleaving protease established. Our data suggest that the unusually large vWF multimers found in TTP patients may be caused by deficient vWF-cleaving protease activity. Deficiency of this protease may be inherited in an autosomal recessive manner and seems to predispose to chronic relapsing TTP. The assay of the vWF-cleaving protease activity may be used as a sensitive diagnostic tool for identification of subjects with a latent TTP tendency.     

Cryosupernatant in thrombotic thrombocytopenic purpura (TTP): is it really useful?

PURPOSE: To identify proptosis as a manifesting sign of Weber-Christian disease (recurrent febrile nodular panniculitis). METHOD: Case report. A 61-year-old man had signs of right proptosis and orbital inflammation that resolved with oral corticosteroid therapy. Orbital inflammation later recurred with associated cutaneous nodules, myalgia, nausea, and malaise. RESULTS: Rheumatologic evaluation and subcutaneous nodule biopsy led to the diagnosis of Weber-Christian disease. The patient required systemic immunosuppressive agents to control the disease. CONCLUSION: This case shows the rare finding of proptosis as the manifesting sign of Weber-Christian disease.     

Hepatic veno-occlusive disease in a case of polymyositis associated with thrombotic thrombocytopenic purpura/hemolytic uremic syndrome

A 50-year-old woman was treated with prednisolone for polymyositis. During the therapy, thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS) occurred. Neither plasma infusion nor plasma exchange could relieve the clinical manifestations of TTP/HUS. Moreover, massive ascites appeared and worsened her condition. She died approximately one year after the diagnosis of polymyositis. The autopsy revealed centri-lobular hepatic necrosis and nonthrombotic obliteration of hepatic small veins. The diagnosis of hepatic veno-occlusive disease (VOD) was made. It was suspected that common factors other than cytoreductive therapy had damaged the endothelium and caused TTP/HUS and VOD in a case of polymyositis.