Glomerulonephritis associated with MRSA infection: A possible role of bacterial superantigen

Abstract

We report 10 cases of glomerulonephritis following methicillin-resistant Staphylococcus aureus (MRSA) infection. The clinical features of this syndrome were an abrupt or insidious onset of rapidly progressive glomerulonephritis (RPGN) with nephrotic syndrome and occasionally purpura, following MRSA infection. The renal histologic findings showed a variety of types of proliferative glomerulonephritis with varying degrees of crescent formation; immunofluorescence revealed of glomerular deposition of IgA, IgG, and C3. Laboratory findings showed polyclonal increases of serum IgA and IgG, with high levels of circulating immune complexes (ICs). Increased numbers of DR+CD4+, and DR+CD8+T cells were observed in the peripheral circulation, with a high frequency of T cell receptor (TCR) V beta + cells. MRSA produced enterotoxins C and A and toxic shock syndrome toxin (TSST)-1, all of which are known to act as superantigens. From the above observations, we speculate that post-MRSA glomerulonephritis may be induced by superantigens causing production of high levels of cytokines, and polyclonal activation of IgG and IgA. The formation of ICs containing IgA and IgG in the circulation result in development of glomerulonephritis and vasculitis. Accordingly, microbial superantigens may play an important role in the pathogenesis of this unique syndrome of nephritis and vasculitis.

Glomerulonephritis after Methicillin-resistant Staphylococcus aureus Infection Resulting in End-stage Renal Failure.

“…Autoantibodies were not detected in this case that was also consistent with the cases reported previously (1,(3)(4)(5). In most cases with MRSA-GN reported previously, renal pathology showedmesangial and/or endocapillary proliferative glomerulonephritis with various degrees of crescent formation and tubulointerstitial nephritis (1)(2)(3)(4)(5). The present case also showed mesangial proliferative glomerulonephritis with cellular crescent formation and interstitial nephritis.…”

“…From 1995, cases of superantigen-related glomerulonephritis associated with methicillin-resistant Staphylococcus aureus (MRSA)infection have been reported and it is speculated that the enterotoxins of S. aureus mayserve as superantigens in its pathogenesis (1)(2)(3)(4). We present here a patient who developed glomerulonephritis after MRSA infection which resulted in endstage renal failure even though he received prednisolone pulse therapy and plasmapheresis in addition to administration of vancomycin.…”

“…However, C-reactive protein was not normalized even after the partial improvement of renal function. He was discharged and followed infrequently in the out- Most cases with MRSA-GN reveal rapidly progressive glomerulonephritis with various degrees of proteinuria and elevation of serum IgA and IgG (1,4,5). The present case also showed rapidly progressive glomerulonephritis and elevation of serum IgA and IgG.…”

“…The cases of MRSA-GN may have substantially more varied types of features. It is reported that the prognosis of MRSA-GN is relatively good if the appropriate treatment is administered for the MRSA infection, and if the underlying disease does not worsen (1,2,5). In the present case, we speculate that we could prevent the second deterioration of renal function and subsequent requirement of contiuous HDtherapy if we had completely eradicated MRSA.…”

The Modern Spectrum of Renal Biopsy Findings in Patients with Diabetes

“…The overwhelming majority of these diagnoses would yield some change in treatment, ranging from the use of immunosuppression to titration of renin-angiotensinaldosterone system blockade. The most common NDRDs previously reported in patients with DM are IgAN (3,(11)(12)(13), FSGS (1,10), and MGN (10,14). In our series, FSGS was the most common finding in NDRD alone, identified in 48 patients (22%) and, in all but 6 patients, read as secondary or adaptive FSGS related to such comorbidities as obesity and systemic hypertension.…”