Impact of Puberty on Immune Responses to Mycobacterium tuberculosis in South African Adolescents.

BACKGROUND

As individuals progress through adolescence, their risk of tuberculosis (TB) increases, and the type of disease that develops changes, with increasing cavitary formation and parenchymal tissue destruction. While it is widely assumed that the changes in risk and disease phenotype are due to puberty exerting an impact on host immune responses to Mycobacterium tuberculosis, this relationship has been poorly studied.

METHODS

Teen TB was an observational study that recruited 50 adolescents with pulmonary TB and 50 controls exposed to TB in Cape Town, South Africa. Blood was collected at baseline and again at month 2 from those with TB. Concentrations of 43 cytokines and 19 hormones were measured and compared between individuals with TB and controls, and changes were monitored over time in those with TB. The relationship between Tanner stage and cytokine/endocrine concentrations was also assessed.

RESULTS

IL-1ra, IP-10, SAP, cortisol, lipocalin 2, and resistin were higher, while ghrelin, T3, and DHEAS were lower, in adolescents with TB vs healthy controls. DHEAS, progesterone, luteinizing hormone, testosterone, C peptide, estradiol, and cortisol were positively correlated and T3 negatively correlated with Tanner stage in healthy controls. In adolescents with TB, there was no association between Tanner stage and cytokine/endocrine markers.

CONCLUSIONS

While in healthy individuals there was a strong association between Tanner stage and endocrine markers, this relationship was absent in adolescents with TB. TB disease appears to disrupt the normal physiologic process of puberty. This could have a substantial impact on growth and development for adolescents developing TB during this critical time.