A 32-year-old Asian woman received a successful two-antigen mismatched deceased donor renal transplant. She underwent Alemtuzumab and Methylprednisone induction. The immediate posttransplant course was uncomplicated. She was discharged with a nadir serum creatinine of 0.9 mg/dL. Immunosuppression consisted of Mycophenolic acid delayed release (MMF) 720 mg twice daily and Tacrolimus therapy (target trough 9-12 ng/mL). Three months after transplant the patient developed elevated liver enzymes associated with fever of 102 F. Initial blood cultures, CMV, parvovirus B-19 and EBV by quantitative polymerase chain reaction were negative. Computed tomographic imaging studies (CT) revealed periaortic lymphadenopathy (Figure 1). Liver biopsy revealed noncaseating granulomas and no evidence of posttransplant lymphoproliferative disorder (Figure 2(a)). Para-aortic lymph node biopsy revealed acid fast bacilli which were confirmed to be Mycobacterium tuberculosis (MTB) by nucleic acid amplification test and culture (Figure 2(b)). Review of pretransplant records revealed that the patient developed a 5 mm induration on tuberculin skin testing. Based on a history of prior administration of the BCG vaccine and a completely normal radiograph of the chest, the decision to forego Isoniazid prophylaxis against latent TB was made. Treatment was begun with Isoniazid 300 mg daily, Rifampin 450 mg daily, Ethambutol 800 mg daily, and Pyrazinamide 1000 mg daily. Her immunosuppression was reduced to maintain target Tacrolimus trough levels of 6 ng/mL and MMF was decreased to 180 mg twice daily. Resolution of symptoms occurred after initiation of therapy and reduction of immunosuppression. Five months after initiation of therapy the patient developed fever, weight loss, back pain, and weakness. CT scan demonstrated multiple lobulated peripherally enhancing fluid collections within the iliopsoas muscles as well as within the left hepatic lobe, most suggestive of abscesses (Figure 3). Empirical intravenous Ampicillin/Sulbactam was initiated at 3.1 grams every 8 hours. She underwent drainage of fluid collections, and gram stain, and cultures were obtained. Gram stain and acid fast stain of fluid revealed multiple neutrophils and no organisms. Fluid cultures revealed no growth of bacteria or MTB. The diagnosis of IRIS was established, corticosteroids were not administered, and the patient was maintained on two-drug anti-TB therapy consisting of Rifampin and Isoniazid. During the course of therapy, she was rehospitalized for fever of unknown origin.
Fever, abdominal pain, and fullness slowly resolved over the course of therapy. Repeat CT imaging of the abdomen revealed resolving iliopsoas fluid collections (Figure 4). After 4 months of 4-drug regimen, the patient was continued on Rifampin and Isoniazid. The patient finished one year of antituberculosis therapy and has remained symptom-free with a functioning allograft. This patient received lymphocyte depleting induction with Alemtuzumab and her immunosuppression was reduced after the diagnosis of active TB. As IRIS may occur in the setting of treatment for TB and immune reconstitution, the time course of her illness and her total lymphocyte count are displayed (Figure 5).