The following is a summary of “Pooled prevalence of lymphopenia in all-cause hospitalizations and association with infection: a systematic review and meta-analysis,” published in the December 2023 issue of Infectious Disease by Elçioğlu et al.
Lymphopenia, characterized by abnormally low levels of lymphocytes in the blood, is linked to an increased risk of infection and mortality in both the general population and hospitalized patients.
Researchers performed a retrospective study to determine the prevalence of lymphopenia and its impact on clinical outcomes in hospitalized patients.
They executed a peer-reviewed search on three databases to summarize the pooled prevalence of lymphopenia. Studying infections, they prioritized pre-existing lymphopenia as a risk for admission and in-hospital healthcare-associated infection. Secondary outcomes included length of stay and mortality, with data for in-hospital, 28/30-day (‘early’), and 90-day/1-year (‘late’) periods. Using random-effects models, a meta-analysis assessed each outcome, measuring heterogeneity with the I2 statistic. Bias risk was evaluated using the Joanna Briggs Institute checklist for cohort studies, and the protocol was published on PROSPERO.
The results showed 15 observational studies with a pooled prevalence of lymphopenia in all-cause hospitalizations at 38% (CI 0.34-0.42, I2=97%, P<0.01). Lymphopenia showed no association with infection diagnosis at hospital admission and healthcare-associated infection (RR 1.03; 95% CI 0.26-3.99, P=0.97, I2=55% and RR 1.31; 95% CI 0.78-2.20, P=0.31, I2=97%, respectively). However, it was linked to septic shock (RR 2.72; 95% CI 1.02-7.21, P=0.04, I2=98%). Furthermore, lymphopenia correlated with elevated in-hospital mortality and ‘early’ mortality rates (RR 2.44; 95% CI 1.71-3.47, P<0.00001, I2=89% and RR 2.05; 95% CI 1.64-2.56, P<0.00001, I2=29%, respectively). It was also associated with increased ‘late’ mortality (RR 1.59; 1.33-1.90, P<0.00001, I2=0%).
Investigators concluded that the high prevalence of lymphopenia in hospitalized patients was linked to an increased risk of septic shock early and late mortality.
Source: bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-023-08845-1
