IgA Nephropathy with Gross Hematuria Following COVID-19 mRNA Vaccination

Abstract

A 28-year-old woman experienced gross hematuria after the administration of the second dose of an messenger ribonucleic acid (mRNA) vaccine (BNT162b2). She was diagnosed with Immunogloblin A nephropathy (IgAN) by a renal biopsy two weeks after vaccination, which revealed a mild increase in mesangial cells and a matrix with co-depositions of galactose-deficient IgA1 and C3 in the mesangial region. The gross hematuria and proteinuria gradually improved without any medication, suggesting that immune activation by the mRNA vaccine may not elicit continuous disease progression of IgAN. Thus, further studies investigating the relationship between mRNA vaccines against COVID-19 and the progression of IgAN should be conducted.

Keywords: COVID-19; IgA nephropathy; gross hematuria; mRNA vaccine.

Figure 1.

Light microscopic findings of the renal biopsy sample showing the mild increase of mesangial cells and endocapillary proliferation. Periodic acid-Schiff staining was performed.

Figure 2.

Immunofluorescence staining of the renal biopsy samples. IgA, galactose-deficient IgA1 (Gd-IgA1), and C3. The samples were stained with anti-IgA and C3 antibodies (Ab) (FITC) and anti-Gd-IgA1 monoclonal Ab (KM55; PE).

Figure 3.

Electron microscopic findings of renal biopsy samples. The red arrow indicates electron-dense deposits in the paramesangial region.

Figure 4.

Clinical course of the present case. Serum (blue line) or urinary (red line) Gd-IgA1 levels. These were measured on the indicated days using enzyme-linked immunosorbent assays. The number of urinary red blood cells/high-power field on the indicated days is shown (rectangle).