Second Generation Direct-Acting Antiviral Agents Eradicate Hepatitis C Virus (HCV) but Exacerbate Thrombocytopenia in a Patient with HCV-Associated Immune Thrombocytopenic Purpura (ITP): Case Report
Authors: Lee Le Min , Johansen Max E , Jy Wenche , Horstman Lawrence L , Ahn Yeon-Soong 
Published: October 2019

Abstract
Background
Lymphotropism of HCV induces chronic immune stimulation, facilitating production of wide variety of autoantibodies, leading to HCV driven autoimmunity. Immune thrombocytopenic purpura (ITP) is one of extra hepatic manifestations of autoimmune diseases in HCV infection.
The treatment landscape of hepatitis C virus infection has been dramatically altered in 2013 with the approvals of the second-generation protease inhibitor simeprevir and the nucleotide polymerase inhibitor sofosbuvir. In most patients treated with the direct-acting antiviral agent (DAA), HCV RNA became undetectable.
However a little is known about how DAA therapy affects autoimmune diseases associated with HCV, especially in ITP. Cessation of immune stimulation by HCV following the treatment may alter immune responses and may modify autoimmune diseases.
We report here a case of acute exacerbation of ITP following DAA treatment. DAA therapy appears to precipitate acute exacerbation of thrombocytopenia and ITP became refractory to all treatments including the measures that used to induce remission prior to DAA treatment.
Case report
A 67-year-old man was diagnosed chronic HCV infection, genotype 1b, in 1997. He failed treatment with Interferons. Chronic active hepatitis subsequently progressed into cirrhosis with portal hypertension. His ITP required frequent treatments with Prednisone and IVIG. It became severe in early 2013. His platelet counts were low at 10,000. He responded well to high dose Prednisone but could not continue because of worsening diabetes. He also failed Rituxan. He received multiple treatments including eltrombopag and romiplostin which he did not respond well to. His ITP finally stabilized with monthly infusion of WinRho as maintenance therapy with platelet counts hovering around 40.000 for 6 months.
In March 2014, he was started on HCV treatment with simeprevir, sofosbuvir and ribavirin. His baseline platelet count prior to the new treatment was in the 50000’s. It plummeted to below 10.000 two weeks into treatment. He developed multiple ecchymosis and blood blisters in the mouth. He completed his HCV treatment on June 3, 2014. His viral load was no longer detectable.
However, ITP remained refractory and severe with platelet counts around 10,000. High dose Prednisone or WinRho which had been effective in raising platelet counts previously were no longer effective after DAA therapy. During this acute exacerbation of ITP, he was treated with IVIG 3 times a week and low dose Prednisone and NPlate weekly with increasing dosage. He developed frequent blood blisters in mouth and gum bleeding requiring emergency room visits and hospitalization where he received platelet transfusions along with IVIGG and high dose Prednisone. His hemoglobin was stable throughout. IVIGG was reduced to 2 times a week. At 8 weeks following completion of DAAs, his platelet count improved to 40.000s range without clinical sign of bleeding.
Discussion
It has been shown that the frequency of B-cell production of anti- GPIIb-IIIa antibody, an antibody against the major platelet surface autoantigen (BP IIb-IIIa) recognized by anti-platelet antibodies in patients with idiopathic thrombocytopenic purpura (ITP), was greater in HCV-ITP (9). An inverse correlation was found between platelet count and B-cell anti–GPIIb-IIIa Ab production in 51 patients with liver cirrhosis (73% with hepatitis C).
In our patient, ITP was stable with maintenance infusion of WinRho for 6 months. Acute exacerbation of ITP 2 weeks into DAA therapy suggests that it was triggered by the DAAs. Thrombocytopenia is a well-recognized complication of interferon therapy for treatment of viral hepatitis. Simeprevir and sofosbuvir however, are not well known to affect the platelet count.
A little is known on effect of DAAs on thrombocytopenia. Immune alteration following eradication of HCV and subsequent modification of autoimmunity could affect course of ITP associated with HCV infection. Meanwhile, it is important for physicians and patients to be aware of potentially dangerous complications of these second generation DAAs.

Disclosures
No relevant conflicts of interest to declare.