Incidencia, diagnósticos y supervivencia global de una población con lactato deshidrogenasa sérica extremadamente elevada de un centro de alta complejidad de la Ciudad Autónoma de Buenos Aires

Introduction. Few studies have focused on patients with severely elevated serum lactate dehydrogenase (LDH), which may serve as an excellent biomarker for a specific group of severe diseases. Materials and Methods. The aim was to analyze the incidence, associated diagnoses, and overall survival of adult patients with markedly elevated LDH (≥1000 U/L) through a retrospective dynamic cohort study conducted at a university hospital in the Autonomous City of Buenos Aires, between January 1, 2011, and December 31, 2018. Results. The lowest crude cumulative incidence was recorded in 2011, with 3.31 cases (95% CI: 2.39–4.48) per 10,000 adult patients, and the highest in 2016, with 6.1 (95% CI: 4.85–7.47). Of 522 patients, 433 (83%) presented with LDH ≥ 1000 U/L in the context of oncologic disease or shock/multiorgan failure. Among them, 251 (48.08%) had non-oncologic causes (35.06% non-septic shock or multiorgan failure, 29.48% due to sepsis, and 35.46% other causes), while 271 (51.92%) had malignant causes (58.30% metastatic solid tumors and 41.70% hematologic malignancies). Median survival was 32 days (95% CI: 25–44), and one-year survival was 32.61% (95% CI: 28.59–36.68). Patients with solid tumors showed the highest mortality: median survival of 19 days (95% CI: 13–25) and one-year survival of 6.01% (95% CI: 2.98–10.56). Older age, male sex, diagnosis of solid tumor or hematologic malignancy, presence of shock and/or multiorgan failure, LDH > 2000 U/L, and diagnosis during 2011–2012 were independently associated with increased risk of death during follow-up. Discussion and Conclusion. The identification of severely elevated serum LDH provides valuable diagnostic and prognostic information. In patients with solid tumors, it may be considered a marker of terminal illness, useful for evaluating the initiation of palliative care and the discontinuation of oncologic-specific treatments.