Platelet and Red Cell Indices: A Potential Biomarker for Predicting Pulmonary Hypertension in Chronic Obstructive Pulmonary Disease (COPD) Patients.

Introduction:  Chronic obstructive pulmonary disease (COPD) is a chronic progressive condition marked by inflammation and airflow limitation. Platelets and red blood cells play an important role in the pathogenesis of COPD and pulmonary hypertension (PH) by mediating thrombotic, inflammatory, and immune processes in the lungs. Blood indices, such as platelet-to-lymphocyte ratio (PLR), platelet distribution width (PDW), plateletcrit (PCT), red cell distribution width (RDW), mean platelet volume (MPV), and platelet count (PLT), have emerged as potential biomarkers for predicting the severity of PH. This study compares these indices and clinical profiles between COPD and non-COPD patients.

Objectives:  This study aimed to compare the values of platelet indices and red cell indices between COPD and non-COPD patients and to investigate the predictive value of platelet indices and red cell indices for PH in COPD patients.

Methods:  This cross-sectional study included 100 participants, categorized into two groups: COPD (n = 75) and non-COPD (n = 25). Laboratory parameters, including platelet and red cell indices, and pulmonary function parameters such as post-bronchodilator FEV1, forced vital capacity, and diffusion capacity of carbon monoxide (DLCO), were analyzed. PH severity (mild, moderate, and severe) was assessed by 2D-echo, and statistical significance was determined using t-tests, chi-square tests, and one-way analysis of variance.

Results:  COPD patients had lower lymphocyte counts (1,352.6 ± 483.9 vs. 2,253.4 ± 867.6; p < 0.001), higher PLR (253.8 ± 86.6 vs. 126.5 ± 79.4; p = 0.010), elevated RDW (15.4 ± 0.9 vs. 11.8 ± 1.4; p < 0.001), lower PDW (10.2 ± 1.6 vs. 11.2 ± 1.6), and higher PLT (318,720 ± 99,905.2 vs. 264,500 ± 11,2661.7) compared to non-COPD patients. PLR (p = 0.040), RDW (p <0.001), and DLCO (p = 0.025) predicted PH and increased with the severity of PH, while PDW, MPV, PCT, and PLT did not predict PH.

Conclusion: Blood markers, particularly RDW and PLR, are effective in predicting the severity of PH in COPD patients and can be used in early suspicion and diagnosis of PH in COPD patients, especially in low-resource settings.