In recent years, several laboratories have suggested that
chronic hepatitis C virus (HCV)
infection is strongly associated with type II
cryoglobulinemia (CG) and/or
membranoproliferative glomerulonephritis (MPGN). We report here a case of MPGN due to type II CG probably associated with chronic HCV
infection, and discuss the pathogenesis and treatment of such cases. A 60-year-old-female was referred to us from a local hospital because of progressive peripheral
edema,
purpura on the lower limbs,
pleural effusion,
ascites,
hypertension, and
renal failure. Laboratory findings indicated
proteinuria, abnormal urinary sediments, normochromic normocytic
anemia and
azotemia. Other laboratory findings included positive
rheumatoid factor, elevated serum
IgM, hypocomplementemia and elevated circulating
immune complexes.
Cryoglobulin was detected and found to consist of a mixture of a monoclonal
IgM kappa with polyclonal
IgG. Renal biopsy showed MPGN. These observations suggested a close association between MPGN and type II CG. We did not find any causes of type II CG except for positive HCV antibody and HCV
RNA. Therefore, we made the diagnosis of type II CG associated with chronic HCV
infection. Symptoms related to CG was responsiveness to
steroid, but development of
liver dysfunction developed. Treatment with alfa-
interferon (alpha IFN) was added and thereafter, the
liver dysfunction improved. However, the serum Cryo level was not reproducibly lowered. While in this case it was unclear whether IFN
therapy was beneficial, several reports in addition to the findings of this case suggest a close relation between HCV
infection and type II CG and MPGN.(ABSTRACT TRUNCATED AT 250 WORDS)