Effect of direct-acting antivirals on platelet-associated immunoglobulin G and thrombocytopenia in hepatitis C virus-related chronic liver disease

Introduction of direct-acting antiviral agents alters frequencies of anti-GPIIb/IIIa antibody-producing B cells in chronic hepatitis C patients with thrombocytopenia

The pathogenesis of thrombocytopenia in chronic hepatitis C (CHC) conceivably involves autoimmunity; however, the dynamics of autoantibodies and other autoimmune mechanisms remain unclear. In this study, we examined the changes in the frequency of anti-glycoprotein (GP) IIb/IIIa antibody-producing B cells and the levels of plasma B-cell-activating factor (BAFF), a proliferation-inducing ligand (APRIL), and interleukin (IL)-21 following treatment of CHC with direct-acting antiviral agents (DAA). We recruited 28 patients with CHC who underwent treatment with DAA for 8-12 weeks and subsequently tested negative for serum hepatitis C virus RNA. Thirty healthy controls were recruited for comparison. Platelet counts increased significantly (p = .016), and the frequency of anti-GPIIb/IIIa antibody-producing B cells decreased significantly (p = .002) in CHC patients with thrombocytopenia at the end of treatment (EOT) than before DAA treatment (baseline). However, these changes were not observed in CHC patients without thrombocytopenia. Plasma BAFF levels in CHC patients with thrombocytopenia significantly decreased from baseline to EOT (p = .002). Anti-GPIIb/IIIa antibody-producing B cells were positively correlated with plasma BAFF levels in these patients (r = 0.669, p = .039). These results suggest that DAA treatment suppresses the autoimmune response against platelets and improves thrombocytopenia.

Comparison of thrombocytopenia between patients with non-alcoholic fatty liver disease and those with hepatitis C virus-related chronic liver disease

AIM

Thrombocytopenia is widely recognized as a simple surrogate marker of liver fibrosis in non-alcoholic fatty liver disease (NAFLD). Thrombocytopenia of NAFLD has not been compared with that of hepatitis C virus-related chronic liver disease (CLD-C). Here, we examined whether there is any difference in the platelet counts between patients with NAFLD and CLD-C and investigated the underlying mechanisms.

METHODS

A total of 760 biopsy-confirmed NAFLD and 1171 CLD-C patients were enrolled. After stratification according to the liver fibrosis stage, platelet counts between NAFLD and CLD-C patients were compared. The platelet count, spleen size, serum albumin level, serum thrombopoietin level, and immature platelet fraction (IPF) value were also compared after covariate adjustment using propensity score (PS) matching.

RESULTS

The median platelet counts (×10⁴ /μL) of NAFLD and CLD-C patients were 20.2 and 18.7 (p = 2.4 × 10^-5 ) in F1; 20.0 and 14.5 (p = 2.1 × 10^-12 ) in F2; 16.9 and 12.3 (p = 8.1 × 10^-10 ) in F3; and 11.1 and 8.1 (p = 0.02) in F4, respectively. In the F3 group, NAFLD patients had a significantly higher platelet count and significantly smaller spleen volume than CLD-C patients. Although the serum thrombopoietin levels were comparable between NAFLD and CLD-C patients, the IPF value of NAFLD patients was significantly higher than that of CLD-C patients.

CONCLUSIONS

NAFLD patients had a significantly higher platelet count than CLD-C patients following stratification according to the liver fibrosis stage. The milder hypersplenism and higher platelet production in NAFLD than CLD-C may have contributed to this difference.

Factors Associated with Significant Platelet Count Improvement in Thrombocytopenic Chronic Hepatitis C Patients Receiving Direct-Acting Antivirals

To clarify the predictive factors of significant platelet count improvement in thrombocytopenic chronic hepatitis C (CHC) patients. CHC patients with baseline platelet counts of <150 × 103/μL receiving direct-acting antiviral (DAA) therapy with at least 12-weeks post-treatment follow-up (PTW12) were enrolled. Significant platelet count improvement was defined as a ≥10% increase in platelet counts at PTW12 from baseline. Platelet count evolution at treatment week 4, end-of-treatment, PTW12, and PTW48 was evaluated. This study included 4922 patients. Sustained virologic response after 12 weeks post-treatment was achieved in 98.7% of patients. Platelet counts from baseline, treatment week 4, and end-of-treatment to PTW12 were 108.8 ± 30.2, 121.9 ± 41.1, 123.1 ± 43.0, and 121.1 ± 40.8 × 103/μL, respectively. Overall, 2230 patients (45.3%) showed significant platelet count improvement. Multivariable analysis revealed that age (odds ratio (OR) = 0.99, 95% confidence interval (CI): 0.99-1.00, p = 0.01), diabetes mellitus (DM) (OR = 1.20, 95% CI: 1.06-1.38, p = 0.007), cirrhosis (OR = 0.66, 95% CI: 0.58-0.75, p < 0.0001), baseline platelet counts (OR = 0.99, 95% CI: 0.98-0.99, p < 0.0001), and baseline total bilirubin level (OR = 0.80, 95% CI: 0.71-0.91, p = 0.0003) were independent predictive factors of significant platelet count improvement. Subgroup analyses showed that patients with significant platelet count improvement and sustained virologic responses, regardless of advanced fibrosis, had a significant increase in platelet counts from baseline to treatment week 4, end-of-treatment, PTW12, and PTW48. Young age, presence of DM, absence of cirrhosis, reduced baseline platelet counts, and reduced baseline total bilirubin levels were associated with significant platelet count improvement after DAA therapy in thrombocytopenic CHC patients.

Successful Treatment with Crushed Sofosbuvir/Velpatasvir of a Patient with Decompensated Cirrhosis C and Thrombocytopenia

A 36-year-old woman with decompensated liver cirrhosis type C was referred to our hospital to receive antiviral treatment for hepatitis C virus (HCV). She had been diagnosed with intractable epilepsy and cerebral palsy at birth and was managed by central venous nutrition and nasal gastric feeding. At age 34 years, she was diagnosed with thrombocytopenia, probably associated with HCV infection. She showed refractory ascites for several months and was therefore administered crushed sofosbuvir/velpatasvir tablets via a nasal gastric tube. Her HCV infection was successfully eradicated, her ascites disappeared, and thrombocytopenia improved with a marked decrease in platelet-associated IgG.

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.

The Association between the Platelet Count and Liver Volume in Compensated Cirrhosis Patients after the Eradication of Hepatitis C virus by Direct-acting Antivirals

Objective Although most patients who obtain a sustained virological response (SVR) show an improved liver function, some show decreased platelet counts after the eradication of hepatitis C virus (HCV). The aim of this retrospective study was to clarify the association of the liver and spleen volumes with the platelet count after SVR achieved by direct-acting antiviral (DAA) treatment. Methods This study enrolled 36 consecutive patients treated by DAAs who obtained an SVR between September 2014 and December 2018. The liver and spleen volumes were derived from computed tomography scans obtained at pretreatment, SVR, and 48 weeks after SVR. No patient developed hepatocellular carcinoma during this study. Results Compared with pretreatment, the median aspartate aminotransferase, alanine aminotransferase, albumin serum levels, and platelet counts were significantly improved at SVR and 48 weeks after SVR. The liver/spleen volumes per body weight had decreased significantly from 22.5/4.2 mL/kg at baseline to 21.1/3.6 mL/kg at 48 weeks after SVR. The change in the liver volume was associated with the change in the platelet count, and the change in the spleen volume was negatively associated with the change in the serum albumin level. A multivariate analysis identified the change in the liver volume (≥95%, odds ratio 76.9, p=0.005) as the factor associated with improvement in the platelet count at 48 weeks after SVR. The patients with an increased liver volume at 48 weeks after SVR showed an increased platelet count. Conclusion Both the liver and spleen volume decreased significantly after the eradication of HCV. The patients with a re-increased liver volume showed a rapid increase in the platelet count.