2025 Volume 266 Issue 4 Pages 381-386
Despite receiving immunosuppressive therapy, a 37-year-old woman with lupus nephritis experienced refractory nephrotic syndrome and severe kidney dysfunction that necessitated peritoneal dialysis. Thereafter, immunosuppressants were tapered because her lupus symptoms improved. Two weeks after prednisolone termination, she was hospitalized because of acute abdominal pain. A physical examination revealed upper abdominal tenderness. Her dialysate was cloudy and comprised an elevated neutrophil count. A coronavirus disease 2019 test yielded positive results. Infectious peritonitis was suspected, coronavirus disease 2019 was diagnosed, and antibiotic and steroid therapies were initiated. The patient’s symptoms improved rapidly, and steroid therapy was discontinued on day 9. On day 10, she experienced abdominal pain and exhibited an elevated monocyte-predominant dialysate cell count despite antibiotic treatment. The dialysate culture results were negative. Lupus peritonitis was suspected because of her slightly elevated dsDNA antibodies and changes in the dialysate cell fraction. Prednisolone was resumed on day 12. Her symptoms improved immediately, and she was discharged on day 30 without complications. This case highlights unique autoimmune activation by coronavirus disease 2019 (COVID-19) that resulted in unexpected pathological shifts and challenging diagnoses. Clinicians should consider various causes of immune flare-ups in patients with COVID-19 and autoimmune conditions.
