A Case of Nephrotic Syndrome With Minimal-Change Disease and Waldenstrom's Macroglobulinemia

Podocytopathy in patients with monoclonal gammopathy: three patients and literature review

BACKGROUND

Renal manifestations of monoclonal gammopathies are of increasing interest among nephrologists. Typical manifestations include light chain cast nephropathy, amyloidosis or renal damage mediated by monoclonal immunoglobulin deposition. Podocytopathies in the setting of an underlying monoclonal gammopathy constitute a rare manifestation of these diseases and, although being described in the literature, remain a challenge since most data derive from case reports.

METHODS

A retrospective review of the clinical data of Hospital del Mar and Hospital Vall d'Hebron was performed to identify patients with minimal change disease (MCD) or focal and segmental glomerulosclerosis (FSGS) in the setting of neoplasms that produce monoclonal (M) protein. Additionally, a literature review on this topic was performed. This study aims to describe the clinical characteristics and outcomes of these patients.

RESULTS

Three patients were identified to have podocytopathy and monoclonal gammopathy between the years 2013 and 2020. All three were males and  >65 years of age. Two patients were diagnosed with MCD and one patient was diagnosed with FSGS. All patients underwent a kidney biopsy and light and electron microscopic studies were performed. The underlying causes of monoclonal gammopathy were multiple myeloma in two cases and Waldeström macroglobulinemia in one case. Two patients developed nephrotic syndrome during the follow-up. All patients were under active hematological treatment. One patient presented a complete remission of proteinuria whereas the other two presented a partial remission.

CONCLUSIONS

Podocytopathies may infrequently be found in patients with monoclonal gammopathies. Patients with overt glomerular proteinuria and hematological disorders with M protein should undergo a kidney biopsy for prompt diagnosis and to specify a prognosis. In addition, further study on this matter must be done to understand the pathophysiology and treat these patients appropriately.

Pseudothrombus deposition accompanied with minimal change nephrotic syndrome and chronic kidney disease in a patient with Waldenström's macroglobulinemia: A case report

BACKGROUND

Waldenström's macroglobulinemia (WM) is a rare lymphoid neoplasia, which can have renal complications. These rarely occur, and most common renal manifestations are mild proteinuria and microscopic hematuria. Herein we describe a case of WM that presented with pseudothrombi depositing in capillaries associated with minimal change nephrotic syndrome and chronic kidney disease (CKD).

CASE SUMMARY

A 52-year-old man presented with features suggesting nephrotic syndrome. Extensive workups were done, and there were elevated serum levels of interleukin-6 and vascular endothelial growth factor (VEGF), capillary pseudothrombus accumulation associated with minimal change nephrotic syndrome, CKD, and WM. Treatment was directed at the patient's WM with bortezomib, thalidomide, and dexamethasone whereby serum immunoglobulin M (IgM) decreased. The damage of IgM on the kidney was corrected; thus, the patient's proteinuria and serum creatinine had improved. The patient is still under clinical follow-up.

CONCLUSION

It is essential for clinicians to promptly pay more attention to patients presenting with features of nephrotic syndrome and do extensive workups to come up with a proper therapy strategy.