HCV-Negative Mixed Cryoglobulinemic Glomerulonephritis and Solid Malignancy: A Case Report and Review of the Literature

[Introduction]In this report, we present a rare case of HCV-negative cryoglobulinemic glomerulonephritis and recurrent prostate cancer in a 79-year-old Caucasian man. In the literature, only a few cases of solid cancer-associated cryoglobulinemia have been reported, but none have shown both renal involvement and prostate cancer.[Case Presentation]A 79-year-old Caucasian man with limb and abdominal purpura, peripheral edema, nausea, and oligoanuric renal failure was admitted to our renal unit in July 2016. In 2007, the patient was successfully treated with radiotherapy for localized prostate cancer and underwent regular follow-up until July 2016 when he developed a recurrence of prostate cancer and was treated with radiotherapy. He was obese and affected by hypertension and stable mild chronic kidney disease (last serum creatinine level, 1.4 mg/dL in July 2016). Serum creatinine level was 5.9 mg/dL upon admission, and blood urea nitrogen was 250 mg/dL with a urinary output of almost 400 ml/day. He tested negative for HCV infection, but positive for type II cryoglobulinemia. Considering the severity of the clinical course of renal biopsy, renal histology was performed, demonstrating cryoglobulinemic membranoproliferative glomerulonephritis. Given the concomitant recurrence of prostate adenocarcinoma, pulse steroid therapy was initiated, followed by prednisone (1 mg/kg/day), without using others immunotherapy agents, such as cyclophosphamide and/or rituximab. Limb and abdominal purpura improved after steroid therapy, whereas renal function failed to recover and hemodialysis treatment was initiated after positioning a central venous catheter. Hemodialysis treatment ameliorated the clinical status of our patient, who is still under chronic treatment.[Conclusions]Type II mixed cryoglobulinemia (MC) is a vasculitis of unknown etiology. HCV infection is the major cause of nearly 90% of MC cases. However, contribution of genetic and/or environmental factors remains controversial, as approximately 10% of MC cases present no evidence of HCV infection. These cases are defined as essential MC and are generally associated with a severe course of and suboptimal responses to conventional therapies. This documented report provides the basis for a comprehensive literature review of the rare occurrence of HCV-negative paraneoplastic cryoglobulinemia.