Usefulness of the lactate dehydrogenase test in Cuban patients deceased with AIDS and Pneumocystis jirovecii pneumonia

Abstract

Introduction: Pneumocystis jirovecii pneumonia is one of the diseases causing the greatest negative impact on AIDS patients. The impossibility of culturing its causative agent, its unspecific clinical presentation and the high cost of molecular diagnostic methods, make it necessary to find other diagnostic alternatives. The lactate dehydrogenase test is an option to be considered.

Objective: Demonstrate the usefulness of the lactate dehydrogenase test to diagnose Pneumocystis jirovecii in Cuban patients deceased with AIDS.

Methods: A case–control study was conducted (25 cases [Pneumocystis jirovecii] and 30 controls [distributed into three groups: tuberculosis, lymphoma and bacterial pneumonia, respectively]) of Cuban deceased patients undergoing post-mortem examination from January 1996 to December 2016. Five cutoff ranges were used to find the optimal value of the test.

Results: Highly significant differences were found between the patients analyzed (cases and controls) and between the remaining individuals making up the controls with respect to the one with lymphoma. The optimal cutoff range for the lactate dehydrogenase test was 550-<800U/I, with 80% sensitivity and 63% specificity. The odds ratio (OR) showed that probabilities are 6.91 times greater that Pneumocystis jirovecii pneumonia patients have higher LDH figures than control patients.

Conclusions: Scientific evidence is contributed of the role of the lactate dehydrogenase test as a complementary tool in the diagnosis of Pneumocystis jirovecii.