Lactate dehydrogenase as a prognostic marker of renal transplant recipients with severe community-acquired pneumonia: a 10-year retrospective study

Background: Lactate dehydrogenase (LDH) is an easily accessible biological marker that has been associated with several pulmonary disorders. The aim of this study was to investigate the prognostic value of serum LDH in renal transplant recipients with severe community-acquired pneumonia (CAP). Methods: A total of 77 renal transplant recipients with severe CAP admitted to the intensive care unit (ICU) were screened for eligibility in this retrospective study. Patient characteristics and laboratory tests, such as LDH on day 1 (LDHday 1) and day 3 (LDHday 3) were recorded. Cox regression models were used to assess the performance of LDH to predict 90-day mortality. Results: Median LDH level was higher on day 1 in 90-day nonsurvivors (440 U/L, IQR, 362-1,055 U/L) than in survivors (334 U/L, IQR, 265-432 U/L; P<0.001); median LDH level on day 3 in nonsurvivors was 522.5 U/L (IQR, 457.5-1,058.5 U/L) and in survivors 290 U/L (IQR, 223-387.5 U/L; P<0.001). Analysis of LDH kinetics from day 1 to day 3 showed an increase in nonsurvivors and a decrease in survivors. Moreover, Multivariate Cox analysis showed that LDHday 1 (increase per 100 U/L), LDHday 3 (increase per 100 U/L) and LDH kinetics (increase per 10%) were independently associated with 90-day mortality. Conclusions: Serum LDH levels and LDH kinetics early were independently associated with 90-day mortality in renal transplant recipients with severe CAP. In future, the prognostic role of LDH needs to be warranted.