Maternal Health Characteristics Associated with Idiopathic T Cell Lymphopenia of Infancy

Newborn TREC screening has identified infants with idiopathic T cell lymphopenia (TCL). By convention, lymphopenia resolves by 12 months of age in transient TCL. We aimed to characterize demographic, laboratory, and maternal health characteristics that differentiate infants with transient vs. persistent idiopathic TCL. A single-center retrospective analysis was performed on patients born from September 2010 through August 2021. Chart review was performed on 53 eligible infants with abnormal TREC screening at corrected gestational age 37 weeks or greater. Descriptive statistics were calculated for initial TREC levels, and T-cell lymphocyte counts at initial referral. Mann-Whitney tests compared initial lymphocyte and average TREC counts. Chi-square analysis assessed associations between transient and persistent TCL patients and select maternal characteristics and risk factors. 25 patients demonstrated persistent TCL while 28 had transient TCL. The persistent cohort was 60.0% male and 24.0% white, while the transient cohort was 60.7% male and 21.4% white. Mean maternal age at birth was 29.7 vs 30.6 years in the persistent and transient groups, respectively. Medians initial TREC levels were lower in the persistent group, but not significantly (52 vs. 73 TRECs/µL of blood, p = .219). The median initial lymphocyte counts were significantly lower in the persistent compared to the transient cohort for CD3+ (1176 vs. 2144 cells/µL, p < .001), CD4+ (866 vs. 1460 cells/µL, p <.001) and CD8+ (293 vs. 539 cells/µL, p = .003). Persistent TCL mothers had more chronic comorbidities (44.0% vs 42.9%, χ2 (1, N = 53) = 0.007, p = .933) and gestational complications (60.0% vs 39.3%, χ2(1, N = 53) = 2.27, p = .132) than transient TCL mothers, but these differences were not significant. Persistent TCL infants were more lymphopenic initially than their transient counterparts. No statistically significant differences in maternal chronic comorbidities or gestational complications exist between the transient or persistent TCL infants. Further work is necessary to characterize if specific maternal-fetal stress factors contribute to persistent TCL.