Gross hematuria and IgA nephropathy flare-up following the first dose of Moderna vaccine: A case report

Background: Since the mass vaccination for COVID-19, several case reports indicated the risk of autoimmune disease flare-ups after the vaccination. Among them, COVID-19 vaccine-induced glomerular diseases have drawn attention worldwide. The cases demonstrating the association between the mRNA vaccine and IgA nephropathy (IgAN) exacerbation had been noticed. Mostly mentioned, the flare-ups usually occurred after the second dose. Methods: We present a Taiwanese female with IgAN who developed gross hematuria within only six hours after the first dose of the Moderna vaccine. Results: Six hours after the first dose of Moderna vaccine on 8 June 2021, the patient developed gross hematuria and significantly decreased urine output. All symptoms resolved spontaneously on the fifth day after the vaccination without any intervention. On the fourth day after the vaccination, the patient were able to back to her original condition. Conclusion: This was an intriguing case of IgAN flare-up following the first dose of mRNA-based COVID-19 vaccination.