Endocrine Abstracts

Introduction: We studied the relationship between vitamin D deficiency and tuberculin skin test (TST) to assess the delayed cellular immunity in older age home residents.

Design: This was a case–control study.

Methods: We evaluated TST in 50 nursing home residents (35 women and 15 men, aged 58–89 years) with 25-hydroxyvitamin D (25(OH)D) concentrations <50 nmol. A one-stage TST was performed using 0.1 ml of PPD RT23. An induration ≧10 mm was considered as positive.

Results: Most patients (68%) had vitamin D deficiency (25(OH)D <30 nmol/l). After one-step testing, 40% of residents had positive TST reactions. The total number of leukocytes was significantly higher in TST-positive patients than in those with negative response. Linear regression shows a significant association between induration diameter and patient age (the diameter decreases with age). Linear regression shows a significant association between the induration diameter and the total number of leukocytes (the diameter increases with total leukocytes) and between the diameter and the percentage of neutrophils (the diameter decreases with the percentage of neutrophils). There was no significant correlation between serum concentrations of 25(OH)D and tuberculin reaction.

Conclusion: The present study showed no correlation between serum concentrations of 25(OH)D and TST reactions, but this could be explained in the context of vitamin D deficiency present in all patients included in the study.