Does Trimethoprim-Sulfamethoxazole prophylaxis induce myelosuppression in primary immune deficiency disease patients; A retrospective, 3 groups comparative study.

Abstract

The possible myelosuppression side effect of Trimethoprim-Sulfamethoxazole (TMP-SMX) on primary immune deficiency (PID) patients has not been established yet. Identify if the PID patients are at higher risk of developing myelosuppression secondary to the use of TMPSMX. Retrospective, three groups study, of PID patients (on and off TMP-SMX prophylaxis) and urinary tract infection (UTI) patients received prophylaxis TMP-SMX. Data about CBC results (WBC, ANC, Lymphocytes, RBC, Hemoglobin, and Platelet counts) at baseline, first, and maximum myelosuppression observed during the period of TMP-SMX administration were collected. A total of 122 patients were included in this study (41 PID patients on TMP-SMX prophylaxis, 45 PID patients not on TMP-SMX prophylaxis, and 36 UTI patients on prophylaxis TMP-SMX). There are significant differences noticed in the percentage of patients who developed clinical myelosuppression (i.e. less than normal value for age) in ANC (39.0% vs. 8.9% vs. 16.7%, p = 0.002), RBC (36.6% vs. 13.3% vs. 13.9%, p = 0.014), WBC (41.5% vs. 13.3% vs. 13.9%, p = 0.003), and platelet (24.4% vs. 15.6% vs. 2.8%, p = 0.028) in group 1, 2, and 3, respectively. Significant difference in myelosuppression between the groups was most likely due to the combination of TMP-SMX effect on PID patients rather than the disease or the drug itself. Primary immune deficiency (PID) patients are at higher risk of developing myelosuppression secondary to TMP-SMX prophylaxis (especially ANC) comparing to immune-competent patients or other PID patients who did not receive prophylactic TMP-SMX. Future larger prospective study is required to confirm this association.