The Role of Hepatitis C Virus in the Development of Multiple Myeloma: A Case Study
Authors: Rodríguez García Alba , Linares María , Mennesson Nicolas , Sanchez-Vega Beatriz , Sanchez Ricardo , Fernandez Rafael Alonso , Bigot-Corbel Edith , Hermouet Sylvie , Martinez Lopez Joaquin 
Published: October 2019

Abstract
* A.R. and M.L. have contributed equally.
INTRODUCTION: Despite great advances in knowledge and treatment in the last decade, multiple myeloma (MM) remains an incurable disease. Several studies suggest its association with infectious pathogens, such as hepatitis C virus (HCV) and Epstein Barr virus (EBV). Here we report on the case of a female MM patient in fourth relapse (after VTD treatment + ASCT+ Lenalodomide maintenance and experimental NK therapy + Lenalidomide and lastly Bendamustine), who achieved stable complete response (CR) once her HCV infection was successfully treated, thus establishing a probable relationship between HCV infection and MM in this patient.
METHODS: Serum samples from the patient were analyzed before and after antiviral treatment (Sofusbuvir + Ledipasvir). The HCV burden was determined by RT-qPCR. Additionally, viral loads of EBV and Cytomegalovirus were established by qPCR.The number of tumor plasma clones was determined in bone marrow samples by NGS using the Ion Proton sequencer and a depth of 2000 readings/nucleotide. Monoclonal immunoglobulins (mc Ig) were separated from polyclonal Ig by agarose gel electrophoresis and elution. Mc Ig purity was evaluated by isoelectric focusing and immunodetection with anti-IgG antibodies. Their reactivity to different microbial antigens was determined by means of the multiplex infectious-antigen microarray (MIAA) assay and using the commercial kit INNO-LIA HCV score (Fujirebio).
RESULTS: The patient, age 66, presented with ISS IIA stage MM (56.7 g/L mc IgG, 2.7 g/L free lambda chains, 2.9 mg/L b2-microglobulin, 90% plasma cells in the bone marrow, without genetic alterations, and osteolytic lesions). HCV infection, causing hepatic toxicity, was discovered in this patient before MM disease. The patient was in third relapse of MM treatment when she received anti-HCV treatment. After antiviral therapy, the HCV load in the patient's serum decreased to undetectable levels (Fig. 1a). Simultaneously, the patient achieved CR of MM, with minimal residual disease (MRD) negativity, as assessed by multiparameter flow cytometry (MFC). NGS revealed the existence of at least one plasmacytic clone, which became MRD negative after anti-HCV treatment (Fig. 1b). Before and after anti-HCV treatment, the patient's serum samples were reactive against antigens of various viruses and other microorganisms (Fig. 1c). Agarose gel electrophoresis of pre-HCV treatment samples showed one band of mc IgG, which disappeared after anti-HCV treatment (Fig. 1d). The patient's mc IgG was purified (Fig. 1e) and analysis of its specificity of recognition revealed that it targeted the HCV core protein (Fig. 1f). Three years have now passed after HCV treatment, and the patient remains in stable CR of MM.
CONCLUSION: In this case of refractory MM where the patient's mc IgG targeted HCV, successful HCV eradication with antivirals Sofosbuvir and Ledipasvir resulted in persistent complete remission of MM as well as of hepatitis C. These results suggest that for HCV-positive individuals, a causal relationship exists between HCV infection and the development of MM, and that MM patients infected with HCV would benefit from early anti-HCV therapy.

Disclosures
Martinez Lopez: Celgene: Research Funding, Speakers Bureau; BMS: Research Funding, Speakers Bureau; Jansen: Research Funding, Speakers Bureau; Novartis: Research Funding, Speakers Bureau.