Hematologic Adverse Effects of Standard TB Therapy Pennan Barry, MD MPH California Department of Public Health TB Control Branch Hematologic Adverse Effects of Standard TB Therapy ↓WBC ↓PMN ↓Plt X X X INH X X EMB X X Rif PZA X ↓RBC X X Drug-Resistant TB: A Survival Guide for Clinicians, 2nd ed. Red Cell Aplasia Hemolytic Anemia X X X X Aplastic Anemia X Hematologic Adverse Effects of Standard TB Therapy ↓WBC ↓PMN ↓Plt X X X INH X X EMB X X Rif PZA X ↓RBC X X Drug-Resistant TB: A Survival Guide for Clinicians, 2nd ed. Red Cell Aplasia Hemolytic Anemia X X X X Aplastic Anemia X Thrombocytopenia: Rifampin • Risks – high dose intermittent regimens (up to 6% on biweekly) – cessation and rechallenge • Immune mediated – Rif antigenic as hapten-albumin complex – Rif dependent Ab fix complement on platelets (GPIb/IX) • Extremely rapid onset • Can be severe requiring steroids and platelet transfusion • Complications: subdural hematoma, melena Holdiness Tubercle 1987 | Mori J Infect Chemotherapy 2010 | Kang Neurological Sciences 2010 | Mehta Tubercle and Lung Dis 1996 | Pereira Br J Haematol 2000 Thrombocytopenia: Ethambutol • 2 case reports • Rapid onset after treatment initiation (4-6 days) • Rapid resolution after discontinuation Holdiness Tubercle 1987 | Prasad Tubercle 1989 | Rabinowitz Chest 1982 Thrombocytopenia: PZA • Case reports • Associated with sideroblastic anemia • 1-2 months into treatment Holdiness Tubercle 1987 | Jain Tubercle 1988 | Roseau Rev Mal Respir 2008 Thrombocytopenia: INH • No case reports in last 50 years • package insert : http://www.versapharm.com/media/productinserts/ INH: Anemia • Sideroblastic anemia responsive to B6 (also caused by PZA) – 4-16 weeks into treatment – Microcytic; Normal iron studies – Marrow: normoblastic hyperplasia and ringed sideroblasts – result of INH effects on pyridoxine metabolism • Pure red cell aplasia – Quick recovery with INH cessation – Can occur up to 6 mos into Rx – Induced autoimmunity to RBC precursors • Hemolytic anemia: Coombs’ negative and positive Holdiness Tubercle 1987 | Loulergue Emerg Infect Dis 2007 | Robinson JAMA 1969 | Liu JAMA 1987 Bone marrow aspirate shows ringed sideroblasts, Prussian Blue stain; 1000x -- Liu JAMA 1987 Bone marrow aspirate shows ringed sideroblasts, Prussian Blue stain; 1000x -- Liu JAMA 1987 Rifampin: Hemolytic anemia • Associated with rifampin “flu” syndrome • Acute renal failure • RBC-specific antibodies (recognize Lu and I Ag) • Patterns: – Escalating antibodies with successive intermittent doses – Rapid reaction following reintroduction – Random reaction with continuous daily dosing Holdiness Tubercle 1987 | Neunert Pediatr Blood Cancer 2008 | Pereira Ann Hematol 1991 INH and Rif: Leukopenia • Case control study of 1,525 TB patients at a Tokyo hospital 1987-2000 • 36 had WBC fall to <3.0 on TB Rx (1.2% of men; 5.9% of women); 2 had agranulocytosis • 30 had meds continued: – 19 recovered on Rx; 11 remained leukopenic on Rx • No difference by regimen (HRE, HRS, HREZ) • Leukopenic pts had lower baseline WBC than controls (7.2 vs 5.5, p<.001) Nagayama Kekkaku 2004 Agranulocytosis • • • • • At least 14 cases reported Incidence 0.06% at one Japanese hospital Rif and INH (PZA: 2 case reports) Can occur simultaneously with hepatotoxicity 1-3 months into Rx Shishido Kekkaku 2003 | www.adverse-effects.com+case_reports.html_ | Jenkins Br Med J 1980 | Wong Chest 1994