Wcn26-4633 Granulomatous Interstitial Nephritis: Could It Be Tuberculosis?

Introduction: Calciphylaxis is a rare and life-threatening condition associated with end-stage renal disease, often requiring complex interventions.Kidney transplantation (KT) may be considered in selected cases to improve prognosis.Streptococcal toxic shock syndrome (STSS), caused by Streptococcus pyogenes, is a fulminant infection with high mortality.We report a unique case of STSS occurring 10 years after KT performed for calciphylaxis in lower legs.Methods: A 43-year-old male with a history of peritoneal dialysis initiated 12 years earlier due to unexplained renal failure developed bilateral lower leg ulcers from calciphylaxis 10 years ago.He underwent autologous skin grafting and subsequently received a living donor kidney transplant (LDKT).His renal function remained stable (serum creatinine sCr 1.5-1.8mg/dL) under immunosuppressive therapy.Ten years after the initial transplant, he presented with acute lower limb pain and was admitted emergently for suspected cellulitis.On admission, he was alert (GCS E4V5M6) with vital signs: BT 37.4 C, BP 107/64 mmHg, HR 130 bpm, RR >20/min, SpO 2 90% (5L/min mask).Physical examination revealed pale erythema and petechiae from the distal right thigh to the dorsum of the foot, with marked spontaneous and pressure pain.Laboratory findings included WBC 10,800/L, sCr 2.33 mg/dL, BUN 33 mg/dL, CK 580 IU/L, LDH 360 IU/L, and CRP 21.3 mg/dL.Results: Initial treatment with meropenem and vancomycin was started for presumed cellulitis.Within 5 hours, extensive purpura appeared, and the patient developed shock.On hospital day 2, emergency fasciotomy was performed.On day 3, blood cultures revealed Streptococcus pyogenes (Group A), and antibiotics were switched to ampicillin and clindamycin.Due to rapid progression of necrosis, proximal thigh amputation was performed on day 4. Postoperatively, the patient was managed in the ICU with intensive care including continuous hemodiafiltration (CHDF).A second surgery was required for hematoma evacuation.His condition gradually improved thereafter.He had experienced chronic rejection several years after SSTS, leading to graft failure and a second LDKT.The condition of the autologous skin graft sites had deteriorated in parallel with declining kidney function, manifesting as increased exudation and poor integration.Conclusion: This case highlights the long-term vulnerability of transplant recipients to severe infections such as STSS, even a decade posttransplant.It underscores the importance of early recognition and aggressive intervention, including surgical management, in immunocompromised patients.The unique clinical trajectory-from calciphylaxis treated with skin grafting to KT and late-onset STSS-offers valuable insights into complex infection risks and transplant-related immunological dynamics.I have no potential conflict of interest to disclose.I did not use generative AI and AI-assisted technologies in the writing process.