Post-vaccinal minimal change disease.

To the editor:

Previous reports have described the onset of minimal change disease after the administration of certain vaccines.

Recently a 61-year-old woman was admitted to our hospital 8 days after her first coronavirus disease 2019 (COVID-19) vaccination (BioNTech/Pfizer SARS-CoV-2 COMIRNATY) because of edema and weight gain (6 kg). Medical history included autoimmune hepatitis and hypothyroidism, for which she used tioguanine (20 mg), prednisone (2.5 mg), and levothyroxine (50 μg). Her kidney function and urine sediment had always been normal. Symptoms, consisting of edema in the lower extremities, dyspnea, and oliguria, started 1 day after vaccination. Physical examination revealed edema in the lower extremities without further abnormalities. Laboratory findings showed hypoalbuminemia (21 g/l), an elevated creatinine level (1.47 mg/dl), and nephrotic range proteinuria (12 g/l; Figure 1 ). Urine analysis showed no glomerular erythrocyturia. Diagnostic workup, consisting of anti-nuclear antibodies, anti-neutrophil cytoplasmic antibodies, anti-PLA2R, protein spectrum, free light chains, C3/C4 levels, hepatitis B surface antigen, and hepatitis C virus, was negative. A diagnostic kidney biopsy was performed. Serum creatinine rose to 3.6 mg/dl, and renal replacement therapy was started because of anuria and diuretic resistant fluid overload with pleural effusion and dyspnea. Steroids (1 mg/kg) were administrated, pending biopsy results. Light microscopy did not show significant glomerular nor tubular abnormalities, immunofluorescence was negative, and electron microscopy showed extensive foot process effacement (Figure 2 ), most of which are compatible with minimal change disease. Kidney function gradually recovered with decreasing proteinuria (2.3 g/l). After 3 weeks, hemodialysis could be stopped.

Figure 1

The course of serum creatinine (blue), albumin (orange), and proteinuria (green), from 3 days prior to vaccination to 128 days after vaccination.

Figure 2

Kidney biopsy findings. (a) Light microscopy with Jones stain shows no glomerular or tubular abnormalities. Original magnification ×400. (b) Electron microscopy. Red arrow indicates extensive podocyte foot process effacement. Original magnification ×6000. Bar = 10 μm. To optimize viewing of this image, please see the online version of this article at www.kidney-international.org.

This case adds to other reports of new-onset nephrotic syndrome after COVID-19 vaccination. , If new-onset nephrotic syndrome incidence rises after this type of vaccination, reporting nephrotic syndrome as a side effect in patient information should be considered.