Incidence and clinical profile of tuberculosis after allogeneic stem cell transplantation

Abstract

Background: Patients post allogeneic stem cell transplantation (alloSCT) are expected to be at high risk of tuberculosis (TB) owing to underlying immunosuppression. We conducted a retrospective study in patients post alloSCT for clinical features and factors associated with TB.

Methods: Records of all patients transplanted from January 1, 2012 until December 31, 2015 were reviewed. Diagnosis of TB was considered if Mycobacterium tuberculosis was cultured from clinical samples or acid-fast bacilli (AFB) were demonstrated on histopathology/smears. A presumptive TB diagnosis was considered in the presence of signs and symptoms suggestive of TB with epithelioid cell granulomas, without AFB.

Results: In 175 eligible patients, TB was detected in 5 patients (pulmonary = 4, lymph node = 1), with incidence of 2.84% at median of 258 (157-639) days after transplantation. Cumulative incidence rate of TB among the patients undergoing alloSCT was calculated to be 1.9/100 person-years. Median duration of symptoms was 20 days till diagnosis was confirmed. All patients were started on four-drug anti-tubercular therapy (ATT) with clinical/radiological response in all. Two patients developed hepatotoxicity (transaminitis, n = 1; hyperbilirubinemia, n = 1) following ATT. Presence of chronic graft-versus-host disease (GVHD) (P = .008) and steroid-refractory GVHD (P = .001) was found to be significantly associated with TB.

Conclusion: TB should be suspected in patients with unexplained fever post alloSCT. Active GVHD and ongoing immunosuppression/steroids are possible risk factors. Early diagnosis and treatment can salvage most patients. Hepatotoxicity following ATT is a potential concern.

Keywords: allogeneic stem cell transplant; graft-versus-host disease; immunosuppression; tuberculosis.