Rates of idiopathic childhood nephrotic syndrome relapse are lower during the COVID-19 pandemic.

BACKGROUND: Infections are thought to be primarily responsible for triggering relapse in children with steroid-sensitive nephrotic syndrome (NS). The COVID-19 pandemic promoted physical distancing, facial mask wearing, and greater attention to infection-prevention measures resulting in decreased transmission of infections. We hypothesized there would also be a decreased rate of NS relapse during this period. METHODS: We conducted a single-center retrospective chart review of children with steroid-sensitive NS. Demographics, rate of relapses, and rate of hospitalizations were collected for a baseline pre-pandemic period (BPP) and for the social distancing period during the pandemic (SDP). RESULTS: One hundred twenty-two children with primary steroid-sensitive NS were identified and 109 were followed for the duration of the study period. The paired rate of relapse per subject per year was significantly lower during the SDP (0.6 relapses per subject per year ± 1 SD) compared to the BPP (1.0 relapses per subject per year ± 0.9 SD), P < 0.01. A subgroup of 32 subjects who were newly diagnosed with NS during the BPP similarly had significantly fewer relapses during the SDP (0.8 ± 1 SD) than during the BPP (1.4 ± 1 SD), P = 0.01. CONCLUSIONS: Our results support the hypothesis of lower rates of NS relapse and hospitalizations during social distancing for all subjects in our cohort and a subgroup of those newly diagnosed. Lower relapse rates were likely attributable to decreased transmission of infections and greater attention to infection prevention. A higher resolution version of the Graphical abstract is available as Supplementary information.

Minimal Change Disease Following the Pfizer-BioNTech COVID-19 Vaccine.

We report on the development of minimal change disease (MCD) with nephrotic syndrome and acute kidney injury (AKI), shortly after first injection of the BNT162b2 COVID-19 vaccine (Pfizer-BioNTech). A 50-year-old previously healthy man was admitted to our hospital following the appearance of peripheral edema. Ten days earlier, he had received the first injection of the vaccine. Four days after injection, he developed lower leg edema, which rapidly progressed to anasarca. On admission, serum creatinine was 2.31 mg/dL and 24-hour urinary protein excretion was 6.9 grams. As kidney function continued to decline over the next days, empirical treatment was initiated with prednisone 80 mg/d. A kidney biopsy was performed and the findings were consistent with MCD. Ten days later, kidney function began to improve, gradually returning to normal. The clinical triad of MCD, nephrotic syndrome, and AKI has been previously described under a variety of circumstances, but not following the Pfizer-BioNTech COVID-19 vaccine. The association between the vaccination and MCD is at this time temporal and by exclusion, and by no means firmly established. We await further reports of similar cases to evaluate the true incidence of this possible vaccine side effect.

Lessons for the clinical nephrologist: recurrence of nephrotic syndrome induced by SARS-CoV-2.

SARS-CoV-2 is characterized by a multiorgan tropism including the kidneys. Recent autopsy series indicated that SARS-CoV-2 can infect both tubular and glomerular cells. Whereas tubular cell infiltration may contribute to acute kidney injury, data on a potential clinical correlative to glomerular affection is rare. We describe the first case of nephrotic syndrome in the context of COVID-19 in a renal transplant recipient. A 35 year old male patient received a kidney allograft for primary focal segmental glomerulosclerosis (FSGS). Three months posttransplant a recurrence of podocytopathy was successfully managed by plasma exchange, ivIG, and a conversion from tacrolimus to belatacept (initial proteinuria > 6 g/l decreased to 169 mg/l). Six weeks later he was tested positive for SARS-CoV-2 and developed a second increase of proteinuria (5.6 g/l). Renal allograft biopsy revealed diffuse podocyte effacement and was positive for SARS-CoV-2 in RNA in-situ hybridation indicating a SARS-CoV-2 associated recurrence of podocytopathy. Noteworthy, nephrotic proteinuria resolved spontaneously after recovering from COVID-19. The present case expands the spectrum of renal involvement in COVID-19 from acute tubular injury to podocytopathy in renal transplant recipients. Thus, it may be wise to test for SARS-CoV-2 prior to initiation of immunosuppression in new onset glomerulopathy during the pandemic.

COVID-19 associated with onset nephrotic syndrome in a pediatric patient: coincidence or related conditions?

BACKGROUND: COVID-19 is less frequent in children than in adults and affects the former less severely; despite the fact that respiratory symptoms are the most frequent, in some cases unusual manifestations can be seen. CASE-DIAGNOSIS: We present a 15-year-old boy who tested positive for SARS-COV-2 infection and onset of nephrotic syndrome, without antecedent of kidney disease and who had normal urine tests shortly before being affected by COVID-19. CONCLUSIONS: The patient described in this report, who was admitted due to nephrotic syndrome and respiratory syndrome, tested positive for COVID-19. He, based on the data review by the researchers, is the first reported case of COVID-19 with simultaneous onset of complete picture of nephrotic syndrome. The presence of both diagnoses could be a coincidence or an unusual form of presentation of COVID-19.