Introduction:
IgA-dominant deposition infection-related glomerulonephritis (IgA-IRGN) is rare GN reported in 0.4% of renal biopsies and is increasingly recognised worldwide after first description in 1995. Middle-aged men are predominantly affected and commonly had diabetes mellitus and or cancer. Staphylococcus aureus infection has been described in more than 50% of IgA-IRGN cases. Acute kidney injury (AKI), haematuria, and various degree of proteinuria has been reported and kidney biopsy is diagnostic. The prognosis of IgA-IRGN and treatment protocol is not well established. Clinical data about IgA-IRGN in Middle East region is lacking. We report our experience of infection related GN with dominant IgA deposition.
Methods:
we conducted a retrospective chart review study at Tawam Hospital and seha kidney care over 6 years (January 2018 to May 2024). We included adult patients (age > 16 years) who had biopsy proven diagnosis of IgA-IRGN in setting of active infection. Clinical data and management outcomes were studied and descriptive analysis was used.
Results:
Six patients fulfilled the inclusion criteria. The mean age was 50.6 years and male to female ratio was 2:1. The comorbid conditions in our case series were diabetes mellitus type 2 (n=4, 66.6%), brain tumour (n=1), dyslipidaemia (n=2, 33.3%), and hypertension (n=2, 33.3%). Half of the patients had Staph aureus infection (n=3, 50%) combined with other bacterial infections (Klebsiella pneumonia, E coli) with clinical presentation of Staph aureus bacteraemia with spondylodiscitis (n=1) and bilateral pyelonephritis (n=1). Two patients (33.3%) had disseminated extra-pulmonary tuberculosis infection and one patient had leg cellulitis with negative blood culture. The renal involvement found in our case series were microscopic haematuria, nephrotic syndrome with heavy proteinuria and acute kidney injury stage II-III (mean creatinine 268 micromol/L). The serum complement levels were normal and other autoimmune workups were negative. The kidney biopsies revealed features of IgA-IRGN (endocapillary proliferation, mesangial cellularity, cellular crescents, various degrees of tubular atrophy and interstitial fibrosis, tubulointerstitial nephritis, diabetic nephropathy). The immunofluorescent study showed mesangial immunoreactivity to IgA and C3 as well as mesangial, subepithelial and subendothelial electron dense deposits identified on electron microscopy. The therapeutic management included antibiotics targeting the underling infections and short course of steroid therapy (83.3%). Two patients (33.3%) had complete recovery of renal function and two patients (33.3%) had partial improvement of AKI with loss of follow up. Renal replacement therapy was required for two patients (33.3%) due to septic shock.
Conclusions:
acute kidney injury with new onset nephrotic syndrome in setting of active infection should alert nephrologist about the possibility of IgA-IRGN. The association of disseminated TB infection and IgA – IRGN is very rare. Larger studies are needed to delineate the effectiveness of steroid therapy on top of antibiotics in such rare GN.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.