We report a case of
purpura nephritis complicated with essential mixed
cryoglobulinemia. The patient was referred to our hospital because of a petechial
rash on the lower extremities, microscopic
hematuria, and progressive deterioration of renal function. The presumptive diagnosis of Henoch-Schönlein
purpura (HSP) was made, and the patient was treated with
prednisolone at the dose of 40 mg/day. However, there was a persistent purpuric
skin rash. On the other hand, immunoelectrophoresis of the serum revealed the presence of
IgA-lambda and polyclonal
IgG in the cryoprecipitate. Granular staining for polyclonal rather than monoclonal
IgA and C3 segmentally along the capillary walls demonstrated by immunofluorescence analysis of renal biopsy led to the diagnosis of
purpura nephritis as the major mechanism of renal damage. After three sessions of cryofiltration, the patient's serum
cryoglobulins decreased and the active
rash finally settled, along with improvement of renal function. These observations suggest that the presence of
cryoglobulinemia modulated the
clinical course of HSP in our case. Therefore, the possibility of the latent presence of
cryoglobulinemia in cases with HSP having an active
rash refractory to
steroid treatment should not be overlooked.