Case of membranoproliferative glomerulonephritis due to essential cryoglobulinemia without hepatitis C virus infection

Detectable serum IgM monoclonal gammopathy in non-hepatitis-associated mixed cryoglobulinemic glomerulonephritis: A case report and literature review

Cryoglobulinemia is the presence of circulating cryoglobulin which can cause systemic vasculitis and glomerulonephritis. Monoclonal gammopathy of renal significance is strongly associated with type I cryoglobulinemia, but the role of detectable serum monoclonal gammopathy in mixed (type II) cryoglobulinemia is not clearly established. We report a case of a 71-year-old woman who presented with skin rash, leg edema, and azotemia. Investigations showed a positive result for rheumatoid factor, low complement C4 level, positive result for serum cryoglobulin, and positive M-spike on serum protein electrophoresis and IgM kappa monoclonal gammopathy on serum immunofixation. Kidney biopsy revealed membranoproliferative glomerulonephritis, polytypic IgM-dominant deposits in an immunofluorescence study, and microtubular substructures in an electron microscopic study. After an extensive workup, no evidence of myeloma or lymphoma was found. A diagnosis of monoclonal gammopathy of renal significance-associated mixed cryoglobulinemic glomerulonephritis was made. Due to the detectable IgM kappa monoclonal gammopathy in the patient's serum, clonal-directed therapy was administered. The patient had been in clinical remission after treatment with clone-directed therapy with cyclophosphamide and steroids. The literature review for cases of type II cryoglobulinemic glomerulonephritis that have detectable serum monoclonal gammopathy are summarized in this study.

Mixed cryoglobulinemic membranoproliferative glomerulonephritis due to monoclonal gammopathy of undetermined significance: A case report

RATIONALE

Membranoproliferative glomerulonephritis (MPGN) can be induced by autoimmune diseases, chronic infection, chronic hepatitis, and paraproteins (including cryoglobulinemia). In addition, the mixed cryoglobulinemic MPGN is reported to be highly correlated with hepatitis C virus (HCV) infection.

PATIENT CONCERNS

We reported a rare case of a 61-year-old woman without a history of viral hepatitis infection; she presented with bilateral leg edema and proteinuria. Renal pathology revealed MPGN with multiple positive immunofluorescent staining. The consequent serum survey revealed positive cryoglobulin and monoclonal gammopathy of kappa type of immunoglobulin M. However, bone marrow study showed no obvious plasma cell proliferation, indicating that multiple myeloma was less likely.

DIAGNOSES

This patient's cryoglobulinemic MPGN could be related to monoclonal gammopathy of undetermined significance.

INTERVENTIONS

Oral immunosuppressant.

OUTCOMES

After steroid treatment, her renal function normalized and proteinuria kept in low level.

LESSONS

We demonstrated a rare cause of cryoglobulinemic MPGN without HCV infection, which led to a favorable prognosis after receiving steroid therapy. Moreover, the diagnosis of monoclonal gammopathy should be considered when facing such case and aggressive steroid therapy might be beneficial.

HCV-negative mixed cryoglobulinemia and kidney involvement: in-depth review on physiopathological and histological bases

Type II mixed cryoglobulinemia without evidence of HCV infection but rather with renal involvement has been occasionally described. The pathogenesis of cryoglobulinemic kidney disease is most likely related to immune complex deposition including cryoglobulins, and cryoaggregation after cold exposure could play a pivotal role in clinical expression of cryoglobulinemia. In these cases, acute kidney injury and proteinuria remain the most frequent clinical expression of a cryoglobulinemic glomerulonephritis. Type II cryoglobulinemia with the laboratory finding of both monoclonal and polyclonal cryoglobulins is the most prevalent bio-humoral pattern among HCV-negative phenotypes with renal involvement, while type III cryoglobulinemia with polyclonal Ig is rare. Histological data in renal biopsies support the hypothesis that regardless of the HCV status cryoglobulinemia vasculitis share the same frequent pathological finding of membranoproliferative glomerulonephritides, but other histological patterns have also been observed in a minority of cases. In HCV-negative mixed cryoglobulinaemia, the paraneoplastic origin of the immune dysfunction should be ruled out and sporadic cases have been reported, while there is no cumulative evidence on the prevalence of these tumour-associated manifestations. Moving from the classification criteria and the etiopathogenesis of mixed cryoglobulinaemia, we provide a comprehensive review of the literature on the appearance of the disease with kidney injury in association with malignancies or autoimmune disorders without HCV coexistence.

Vasculitis with renal involvement in essential mixed cryoglobulinemia: Case report and mini-review

The discovery of a strong association between hepatitis C virus (HCV) infection and mixed cryoglobulinemia (MC) has led to an increasingly rare diagnosis of idiopathic essential MC (EMC). The incidence of EMC is high in regions where there is a comparatively low HCV infection burden and low in areas of high infection prevalence, including HCV. The diagnosis of EMC requires an extensive laboratory investigation to exclude all possible causes of cryoglobulin formation. In addition, although cryoglobulin testing is simple, improper testing conditions will result in false negative results. Here, we present a 46-year-old female patient with a case of EMC with dermatological and renal manifestations, highlighting the importance of extensive investigation to reach a proper diagnosis. We review the need for appropriate laboratory testing, which is often neglected in clinical practice and which can result in false negative results. This review also emphasizes the significance of an extended testing repertoire necessary for better patient management. Despite a strong association of MC with HCV infection and other causes that lead to cryoglobulin formation, EMC remains a separate entity. Correct diagnosis requires proper temperature regulation during sample handling, as well as characterization and quantification of the cryoprecipitate. Inclusion of rheumatoid factor activity and complement levels in the cryoglobulin test-panel promotes better patient management and monitoring. Consensus guidelines should be developed and implemented for cryoglobulin detection and the diagnosis of cryoglobulinemic syndrome, which will reduce variability in inter-laboratory reporting.