Leukocyte count and coronary artery disease events in people with HIV: A longitudinal study. Clinical Infectious Disease
Avery and Kleynhans et al. assessed the association between blood leukocyte count and coronary artery disease (CAD) events among people with HIV (PWH) in the Swiss HIV Cohort Study (SHCS).
In this nested case-control study, the authors applied incidence density sampling to select individuals who experienced a CAD event and CAD event-free controls, matched on sex, age, and date of SHCS registration. CAD events included myocardial infarction, coronary angioplasty/stenting, and coronary artery bypass grafting. Associations were evaluated using multivariable conditional logistic regression models, with the latest leukocyte count prior to the event included as exposure.
The study included 2’000 individuals (536 cases and 1’464 CAD event-free individuals). The median age at CAD event was 56 years (IQR 49-63), 87% were male, 30% were heterosexual individuals, 50% were men who have sex with men, and 17% were people who inject drugs. Overall, 536 CAD events occurred: 274 myocardial infarctions, 211 coronary angioplasty/stentings, 39 coronary artery bypass grafting, and 12 fatal CAD cases. Compared to individuals without CAD events, those who experienced a CVD event had a higher median leukocyte count (6’495/μL vs. 5’900/μL), although leukocytosis (>11’000/μL) was infrequent in both groups (4.3% vs. 2.1%). After adjusting for confounders, individuals with a high-normal leukocyte count (in the fifth percentile) had a higher risk of developing a CAD event (adjusted odds ratio 1.59, 95% CI 1.09-2.30) compared to other individuals. This association was partly attenuated when smoking was included in the model.
In summary, the present study shows an independent association between leukocyte count and the risk of CAD events among PWH even when leukocytes were within the normal range, underlining the importance of inflammation in the process of CAD development. The authors conclude that leukocyte counts may identify PWH with an increased risk for CAD events.