Akademik Veri Yönetim Sistemi
Journal of İstanbul Faculty of Medicine, cilt.89, sa.2, ss.135-138, 2026 (Hakemli Dergi)
Cryptosporidiosis is an opportunistic infection caused by Cryptosporidium species. It leads to severe and prolonged diarrhoea in immunosuppressed patients such as paediatric solid organ transplant recipients. We present the case of a 17-year-old male with a history of Crigler–Najjar syndrome type I who underwent living-donor liver transplantation. He was admitted with a 3-week history of vomiting and abundant watery diarrhoea. The patient was maintained on triple immunosuppressive therapy with tacrolimus, methylprednisolone, and mycophenolate mofetil. On admission, stool cultures and antigen assays for parasitic and viral pathogens, including Cryptosporidium parvum, were negative. Despite supportive treatment, his symptoms persisted, and a colonoscopic biopsy was performed. Although the mucosa appeared normal, histopathological examination revealed the presence of C. parvum. Azithromycin 500 mg was administered daily for 10 days, resulting in the rapid resolution of gastrointestinal symptoms. Early recognition and timely therapy may prevent serious complications, including rejection, biliary disease, and septic shock. This case underscores the limitations of stool antigen assays in immunosuppressed paediatric patients and highlights the diagnostic value of endoscopic biopsy in persistent diarrhoea.