A 61-year-old man with bilateral
purpura of the lower limbs and subsequent
edema, was hospitalization after renal dysfunction developed. The presence of hepatitis C virus (HCV)
RNA and
cryoglobulin and the finding of
membranoproliferative glomerulonephritis on renal biopsy led to a diagnosis of HCV-related
glomerulonephritis due to
cryoglobulinemia. Because of the pre-existence of
nephrotic syndrome and the continuously increasing serum level of
creatinine, treatment with cryofiltration,
interferon, and
steroids was started. After 5 cryofiltration sessions, the cryocrit level had decreased to 1% and the levels of serum
creatinine and
proteinuria had also decreased. However, 3 weeks after the start of treatment,
nephrotic syndrome developed again and was accompanied by lower-extremity
mononeuropathy and renal dysfunction. Thereafter, the patient showed disorientation, an
affective disorder, and
delirium, and his condition gradually deteriorated. Radiological examination of the head and examination of the cerebrospinal fluid showed no abnormalities. Despite the withdrawal of the
interferon therapy and the reduction of the
steroid dose, the patient's conditions remained unchanged, and the level of consciousness deteriorated. Although cryofiltration had beneficial effects and
plasma exchange was continuously performed, the patient died on the 74th hospital day. Because of the significant changes due to ventilatory support and
hemorrhage associated with
disseminated intravascular coagulation, the autopsy findings did not allow us to definitively determine whether the symptoms had been caused by the HCV-related
membranoproliferative glomerulonephritis or the
interferon therapy or both. We have reported this case to provide insight into whether
interferon therapy should be administered for HCV-related
membranoproliferative glomerulonephritis with marked neurological symptoms due to
cryoglobulinemia.