Delayed type of hypersensitivity and late allergic reactions in patients with stable COPD

Background: Malnutrition, a common feature among patients with COPD, has ad verse effects on the immune system. Delayed type of hypersensitivity (DTH) tests have been used to evaluate the nutritional and immune status of patie nts and to predict outcome in various conditions. DTH is known to be and la te allergic reaction (LAR) has been suggested to be dependent on T-lymphocy te function. Study objectives: To compare DTH and LAR tests in COPD patients and healthy controls, to investigate whether skin tests have any value in estimating n utritional status and outcome in COPD patients, and to see whether there is any relationship between DTH and LAR. Methods: Twenty-five patients with stable COPD and 20 healthy controls were tested for DTH and LAR. The patients were investigated with spirometry and anthropometric measurements and were followed for 1 year, Results: Both the LAR and DTH reactions were diminished in the patient grou p (p < 0.001) compared with controls. The skin tests did not correlate with anthropometric parameters. DTH correlated to lung function, which was expr essed as FEV1 (percent predicted) (r = 0.56; p < 0.01), and LAR correlated to the number of exacerbations (at 3 months, r = - 0.61; p < 0.01). No corr elation was found between LAR and DTH reactions. Conclusions: We conclude that patients with COPD in stable condition have d iminished DTHs and LARs, Our results indicate that the magnitude of the LAR may be a prognostic marker in patients with COPD.