From the Research
Lactate dehydrogenase (LDH) has a sensitivity of approximately 63-100% for Pneumocystis jirovecii pneumonia (PJP), with the highest sensitivity observed in HIV-positive patients 1. The sensitivity of LDH for PJP can vary depending on the population being studied, with HIV-positive patients tend to have higher sensitivity compared to HIV-negative patients.
- In HIV-negative patients, the sensitivity of LDH elevation was 63% 1.
- In HIV-positive patients, the sensitivity was 100% 1. However, it's essential to note that while LDH is sensitive for PJP, it lacks specificity as many other conditions can also cause LDH elevation, including other types of pneumonia, malignancies, and various inflammatory conditions. Therefore, elevated LDH should prompt further diagnostic evaluation in at-risk patients, including imaging studies and potentially bronchoscopy with bronchoalveolar lavage for definitive diagnosis 2. The combination of elevated LDH, characteristic clinical presentation, and typical radiographic findings provides stronger diagnostic evidence for PJP than LDH elevation alone 2. It's also worth mentioning that the accuracy of LDH for the diagnosis of PCP is relatively low, with an overall accuracy of 52% 1. Thus, LDH should be used as a screening tool rather than a definitive diagnostic test for PJP, and its results should be interpreted in the context of the patient's clinical presentation and other diagnostic findings 1.