Autoimmune thrombocytopenia in response to splenectomy in cirrhotic patients with accompanying hepatitis C

Pathogenesis of Thrombocytopenia in Chronic HCV Infection: A Review

A large proportion of patients with chronic hepatitis C have associated thrombocytopenia (TCP). Due to bleeding risks, TCP, when severe, can limit diagnostic and therapeutic procedures, treatments, and increases risk of complications, especially excessive bleeding. It is important to understand the mechanisms that cause TCP in order to manage it. In general, TCP can be due to increased destruction or decreased production. Proposed mechanisms of increased destruction include autoantibodies to platelets and hypersplenism with sequestration. Proposed mechanisms of decreased production include virus-induced bone marrow suppression and decreased TPO production. Autoantibodies directed against platelet surface antigens have demonstrated an inverse correlation with platelet counts. Hypersplenism with sequestration involves the interaction of portal hypertension, splenomegaly, and platelet destruction. Decreased production mechanisms involve appropriate and inappropriate levels of TPO secretion. There is limited evidence to support viral-induced bone marrow suppression. In contrast, there is strong evidence to support low levels of TPO in liver failure as a major cause of TCP. TPO-agonists, specifically eltrombopag, have been shown in hepatitis C patients to increase platelet counts without reducing portal hypertension or splenomegaly. We conclude that TCP in hepatitis C virus-induced liver disease is often multifactorial, but an understanding of the mechanisms can lead to judicious use of new drugs for treatment.

Effects of phased joint intervention on IL-35 and IL-17 expression levels in patients with portal hypertension

The aim of the present study was to investigate the clinical efficacy of phased joint intervention [percutaneous transhepatic variceal embolization (PTVE) + phased partial splenic embolization (PSE)] in patients with portal hypertension complicated by esophageal variceal bleeding and hypersplenism and the effect of this intervention on interleukin-35 (IL-35)/IL-17 expression. A review of 53 patients with portal hypertension caused by liver cirrhosis and complicated by esophageal variceal bleeding and hypersplenism treated with phased joint intervention was conducted, and portal hemodynamics, routine blood examinations and liver function were determined. Quantitative polymerase chain reaction (qPCR) was used to evaluate EBI3, FOXP3 and IL-17 mRNA expression levels in peripheral blood mononuclear cells (PBMC) before and after the phased joint intervention, while western blot analysis was used to determine their protein expression. All 53 patients required emergency hemostasis resulting in an emergency hemostatic rate of 100%. Varicose veins disappeared, portal hemodynamics and liver function improved subsequent to the intervention. The expression levels of EBI3, FOXP3 and IL-17 mRNA in the postoperative group were significantly lower than the preoperative levels (P<0.01). The protein expression levels of EBI3, FOXP3 and IL-17 in the postoperative group were reduced compared with the preoperative levels. The concentrations of IL-35, IL-6 and IL-17 in peripheral blood were significantly reduced after the phased joint intervention (P<0.01). Serum IL-35, IL-6 and IL-17 levels were positively correlated with total bilirubin and international normalized ratio, and negatively correlated with albumin. The phased joint intervention can effectively treat esophageal variceal bleeding and hypersplenism, and improve liver function. The efficacy of this intervention may be associated with the regulation of immune function.

Effect of splenectomy on platelets associated antibodies in hepatitis C patients with thrombocytopenia

BACKGROUND

This study aimed to assess the role of splenomegaly as a source of platelet-associated immunoglobulins (PAIgs) in thrombocytopenic patients with chronic hepatitis C virus (HCV) infection.

SUBJECTS AND METHODS

The present study was conducted on 63 subjects categorized as follows. Group 1: Included 63 cases diagnosed as patients with HCV liver cirrhosis combined with thrombocytopenia before splenectomy. Group 2: Included the same 63 cases one week after splenectomy. For all subjects included in this study platelets counts were evaluated as well as PAIgs (total Igs, IgG, IgM, and IgA).

RESULTS

All patients were thrombocytopenic before undergoing splenectomy (platelet counts [median 68.5; range 44-95]). After splenectomy all patients achieved normal platelet counts (median 180; range 108-235). The mean ± SD of PAIgs was 64.2 ± 9.6 for total IgG, 53.6 ± 8.1 for IgG, 3.8 ± 2.1 for IgM, 6.7 ± 4.7 for IgA presplenectomy versus postsplenectomy 13.4 ± 19.3 for total Igs, 5.4 ± 1.8 for IgG, 1.9 ± 1.06 for IgM, 2.1 ± 0.9 for IgA, and the differences between pre and postsplenectomy figures were statistically significant (P < 0.001). The correlation studies between platelet count and PAIgs level in patients with chronic HCV infection presplenectomy revealed that there is significant negative correlation between platelet counts and all immunoglobulins (total Igs: r - 0.804, P = 0.000; IgG: r - 0.907, P = 0.000; IgM: r - 0.467, P = 0.002; and IgA: r - 0.519, P = 0.000).

CONCLUSION

Autoimmune mechanism plays an important role in the HCV-associated thrombocytopenia and spleen is a major source of PAIgs.

Antiplatelet antibodies contribute to thrombocytopenia associated with chronic hepatitis C virus infection

Thrombocytopenia is one of the most frequent hematological manifestations of hepatitis C virus (HCV) infection; which typically worsens with progression of the liver disease and can become a major clinical complication. Several mechanisms have been postulated to explain thrombocytopenia in HCV hepatic patients, including immune mechanisms. The aim of the present work is to investigate the role of immune mechanisms as a causative agent of thrombocytopenia in HCV hepatic patients. The study included 50 hepatic patients with HCV infection (30 with thrombocytopenia and 20 with normal platelets counts). Platelets associated glycoprotein specific antibodies were evaluated by flow cytometry and confirmed by quantitative monoclonal immobilization of platelet antibodies (MAIPA). The frequency of platelet associated immunoglobulin (PAIg) in thrombocytopenic HCV positive hepatic patients by FCM was 86.7, 83.3, 46.7 and 33.3% for total PAIg, PAIgG, PAIgM and PAIgA respectively. MAIPA found platelet specific antibodies in 26/30 (86.7%) of patients. The most likely target antigen for platelets antibodies were glycoprotein (GP) IIb/IIIa (30%), followed by GP IIIa (20.5), GP IIb (13.3%), GPIb (13.3%), then GPIa (10%). The platelets count was inversely correlated to the levels of platelets GP specific antibodies (r=-0.42, p=0.024), and significantly parallel to spleen size (p=0.024). Platelet associated glycoprotein specific antibodies represent a common mechanism inducing thrombocytopenia in patients with chronic HCV infections.

Autoimmune thrombocytopenia related to chronic hepatitis C virus infection

Since the identification of hepatitis C virus (HCV) in 1989 as a causative agent for a number of the extrahepatic alterations related to HCV infection an underlying immune mediated pathogenetic mechanism has been postulated. HCV-associated thrombocytopenia may be considered complex and multifactorial in origin, since different mechanisms have been implicated in its pathophysiology. With respect to autoimmune thrombocytopenia in chronic HCV infection, the detection of specific antibodies against platelet glycoproteins have been reported only in a few studies, but no systematic study has been carried out. We examined the clinical, laboratory, and virological characteristics of a case series of 10 patients with autoimmune thrombocytopenia (platelet count <150.0 x 10(9)/L) related to chronic HCV infection. Cases, six males and four females, aged 57.1 +/- 12.6 years, presented high titers of antibodies against platelet glycoprotein (GP) IIb/IIIa, GP Ia/IIa, and/or GP Ib/IX, and no other mechanism involved in the pathogenesis of HCV-associated thrombocytopenia was identified. Furthermore, cases were not associated with particular HCV genotype. Complete platelet response was observed in two patients treated with pegylated interferon plus ribavirin, and partial platelet response was seen in two patients treated with anti-D Ig and one patient treated with corticosteroids. These findings indicate that an autoimmune mechanism may play a role in the pathogenesis of HCV-associated thrombocytopenia in a proportion of these patients.