Clinicopathologic features of infection-related glomerulonephritis with IgA deposits: a French Nationwide study

Background

Infection-related glomerulonephritis with IgA deposits (IRGN-IgA) is a rare disease but it is increasingly reported in the literature. Data regarding epidemiology and outcome are lacking, especially in Europe. We aimed to assess the clinical, pathologic and outcome data of IRGN-IgA.

Methods

Clinical and outcome data from patients from 11 French centers over the 2007–2017 period were collected retrospectively. We reviewed pathologic patterns and immunofluorescence of renal biopsies and evaluated C4d expression in IRGN-IgA. We analyzed the correlation between histological presentation and outcome.

Results

Twenty-seven patients (23 men, mean age: 62 ± 15 years) were included. Twenty-one (78%) had Staphylococcus aureus infection and twelve (44%) were diabetic. At the time of biopsy, 95.2% had haematuria, 48.1% had a serum creatinine level of > 4 mg/dL, and 16% had hypocomplementemia. The most common pathologic presentation included mesangial (88.9%) and endocapillary proliferative glomerulonephritis (88.9%) with interstitial fibrosis and tubular atrophy (IF/TA) (85.1%). Diffuse and global glomerular C4d expression was found in 17.8%, mostly in biopsies with acute or subacute patterns, and was associated with a short delay between infection and renal biopsy compared to segmental and focal staining. After median follow-up of 13.2 months, 23.1% died, 46.2% had persistent renal dysfunction and 15.4% reached end-stage renal disease. Renal outcome was correlated to IF/TA severity.

Conclusions

Infection-related glomerulonephritis with IgA deposits is usually associated with Staphylococcus infections and mainly affects adult men. This entity has a poor prognosis which is correlated to interstitial fibrosis and tubular atrophy severity.

Bilateral renal cortical necrosis with end-stage renal failure following envenoming by Proatheris superciliaris: a case report

Acute bilateral renal cortical necrosis (BRCN) has been reported following envenoming by exotic venomous snakes. Proatheris superciliaris is a rare viper with restricted distribution in east Africa. Very little information is available on envenoming by this species. We herein describe the case of a 60-year-old professional wildlife photographer who was bitten on his thumb while photographing an adult specimen of P. superciliaris that he held at home in France. On admission, physical examination revealed severe hypertension and bruising with edema at the bite site. Within the following 24 h, he developed vomiting, diarrhea, acute lumbar pain and anuria. Laboratory tests showed acute kidney injury (serum creatinine 4.6 mg/dL), with thrombocytopenia, anemia and severe coagulopathy. Contrast-enhanced computed tomography scan revealed hypodense areas in the cortex of both kidneys consistent with diffuse BRCN. As no appropriate antivenom existed, only symptomatic care was given to the patient. Coagulation tests returned to normal within 48 h. The patient was placed on chronic hemodialysis, until he underwent successful kidney transplantation 18 months later. In developed countries, severe complications provoked by snake bites tend to be more frequent with the number of trendy exotic pets. Acute kidney injury, including BRCN, is a classic complication of viper bites. The present case of end-stage renal failure related to diffuse BRCN illustrates the potentially devastating effects of envenoming by P. superciliaris. Clinicians in developed countries should be informed about renal disorders and other potentially fatal complications of venomous snake bites and seek urgent expert advice for optimizing clinical management. Education and coaching of envenomed patients and exotic snake owners is mandatory to prevent dramatic accidents.