Relapse of minimal change disease following the third mRNA COVID-19 vaccination: a case report and literature review.

Mass vaccination is the most important strategy to terminate the coronavirus disease 2019 (COVID-19) pandemic. Reports suggest the potential risk of the development of new-onset or relapse of minimal change disease (MCD) following COVID-19 vaccination; however, details on vaccine-associated MCD remain unclear. A 43-year-old man with MCD, who had been in remission for 29 years, developed nephrotic syndrome 4 days after receiving the third dose of the Pfizer-BioNTech vaccine. His kidney biopsy revealed relapsing MCD. Intravenous methylprednisolone pulse therapy followed by oral prednisolone therapy was administered, and his proteinuria resolved within 3 weeks. This report highlights the importance of careful monitoring of proteinuria after COVID-19 vaccination in patients with MCD, even if the disease is stable and no adverse events occurred during previous vaccinations. Our case report and literature review of COVID-19 vaccine-associated MCD indicated that MCD relapse tends to occur later after vaccination and slightly more often following the second and subsequent vaccine doses than new-onset MCD.

Acute Tubulointerstitial Nephritis in Rosai-Dorfman Disease Mimicking IgG4-related Disease.

Rosai-Dorfman-Destombes disease (RDD) is a non-Langerhans cell histiocytosis characterized by the accumulation of histiocytes inside the lymph nodes or extranodally. The association between RDD and IgG4-related disease (IgG4-RD) is discussed. We herein report a case of RDD manifesting as acute tubulointerstitial nephritis mimicking IgG4-RD. The first renal biopsy showed severe tubulointerstitial nephritis with infiltration of S100-positive histiocytes and IgG4-positive plasma cells; storiform fibrosis and obliterative phlebitis were not confirmed. After prednisolone therapy, IgG4-positive cells and S100-positive histiocytes were decreased, but the IgG4/IgG ratio increased despite clinical improvement. These findings indicated extranodal RDD in the kidney presenting as tubulointerstitial nephritis.

Two episodes of acute dyspnea that were induced by COVID-19 in a peritoneal dialysis patient.

Dialysis patients have an increased risk of coronavirus disease 2019 (COVID-19)-related mortality. Acute heart failure is a frequent, lethal complication of COVID-19, and it is a risk factor for mortality in hemodialysis patients. Therefore, it is crucial to rapidly distinguish heart failure from COVID-19 pneumonia. Here, we report a case of two episodes of acute dyspnea that were induced by COVID-19 in a peritoneal dialysis (PD) patient. The first episode of acute dyspnea was an exacerbation of heart failure caused by COVID-19 when the patient had a volume overload status due to a peritoneal dialysis catheter malfunction. Heart failure induced by a catheter malfunction was due to omental wrapping, and it was treated with ultrafiltration by hemodialysis and mini-laparotomy. The patient's acute dyspnea was immediately resolved. The second episode of acute dyspnea was caused by COVID-19 pneumonia, which occurred 1 week after the first episode. This case suggests the importance of identifying heart failure and beginning adequate treatment, in COVID-19 patients with PD.