A 72-year-old Japanese woman with a 40-year history of lupus nephritis presented with leg edema that had lasted for several weeks. The disease had previously been induced into remission with high-dose prednisolone and cyclophosphamide, and remission was maintained with prednisolone, 2.5 mg/d. Results of renal biopsy showed global mesangial expansion and hypercellularity with thickening of the glomerular capillary walls. Immunofluorescence studies found the full-house pattern of IgG, IgA, C3, and C1q deposition in the mesangial area and on the glomerular capillary walls.
Diagnosis and Treatment
Clinicians diagnosed the patient with nephrotic syndrome due to a relapse of lupus nephritis and increased the dose of prednisolone to 30 mg/d while also adding tacrolimus, 1.5 mg/d. The hypocomplementemia and cryoglobulinemia improved immediately, but the nephrotic syndrome persisted. The patient previously had chronic infection with HCV genotype 2b with an HCV RNA level of 5.2 log10 IU/mL with normal serum aminotransferase levels and no evidence of hepatitis or cirrhosis on abdominal ultrasonography. The researchers hypothesized that the nephrotic syndrome might be related to the HCV infection and treated the patient with sofosbuvir, 400 mg/d, and ribavirin, 600 mg/d. After treatment, the patient’s nephrotic syndrome improved dramatically.
The patient achieved a sustained virologic response after 12 months of antiviral therapy. The lupus nephritis and nephrotic syndrome have been in remission for 2 years with prednisolone, 5 mg/d, and tacrolimus, 1.5 mg/d. Autoantibody levels also have remained decreased, with antinuclear antibody titers decreasing from 1:640 to 1:80 and anti–double-stranded DNA antibody levels decreasing from 31 to less than 12 IU/mL.
Because of increased interferon stimulated by chronic HCV infection, the researchers believed that the patient had lupus nephritis syndrome despite receiving immunosuppressive therapy. Although nephrotic syndrome can be caused by HCV infection, the presence of systemic lupus erythematosus, anti–double-stranded DNA antibodies, and a full-house immunofluorescence pattern supports the diagnosis of lupus nephritis.
“We believe that these findings suggest that the patient’s lupus nephritis may have required both interferon and TNF-ɑ,” the researchers concluded. “Immunosuppressive therapy may have decreased TNF-ɑ but not interferon; furthermore, antiviral therapy did decrease viral antigen, which we believe was followed by decreased production of interferon and thus of antibodies and eventually led to remission of the lupus nephritis and nephrotic syndrome.
Nakamura H, Fujieda Y, Yasuda S, Nakai M, Atsumi T. Remission of nephrotic syndrome after therapy for chronic hepatitis C virus infection in a patient with systemic lupus erythematosus. Ann Intern Med. 1 May 2018. DOI: 10.7326/L17-0759