Case Report: Contezolid-containing regimens for disseminated Bacillus Calmette-Guérin disease in three children with primary immunodeficiency.

INTRODUCTION

Disseminated Bacillus Calmette-Guérin (BCG) disease is a rare but life-threatening complication in children with primary immunodeficiency (PID). Linezolid (LZD) is effective but limited by myelosuppression. Contezolid (CZD), a novel oxazolidinone, has shown better hematological safety in adults, but pediatric data are scarce. This retrospective case series aims to provide real-world experience on CZD use in this challenging population.

CASE DESCRIPTION: We report three children (aged 3-9.5 months) with PID (Wiskott-Aldrich syndrome, X-linked severe combined immunodeficiency, and IL-12 receptor β1 deficiency) who developed clinically presumed or confirmed disseminated BCG disease after routine vaccination. All received CZD-containing regimens (12-20 mg/kg/dose, q12 h) alongside other antimycobacterial agents and hematopoietic stem cell transplantation (HSCT).

OUTCOMES: Over 11-12 months of CZD-containing multidrug therapy followed by 1 year of post-treatment telephone follow-up, all patients achieved satisfactory clinical resolution of infectious lesions and no clinical relapse was observed. No CZD-attributable hematological, hepatic, renal, or neurological adverse events occurred. However, because all patients received concurrent HSCT and multiple antimycobacterial agents, the independent contribution of CZD cannot be determined.

CONCLUSION

CZD-containing regimens were well tolerated and associated with clinical improvement in these complex cases. CZD may serve as a valuable alternative when LZD is poorly tolerated. However, definitive attribution of efficacy to CZD alone is precluded by concurrent HSCT and multi-drug therapy.