Could Platelet Indices Act as an Effective Diagnostic Marker for COPD?

In patients with chronic obstructive pulmonary disease (COPD), platelet indices may be altered and therefore act as a valuable diagnostic marker in COPD development, according to a recent study.

The research, published by Biochemic Medica, aimed to determine the differences in platelet-related parameters between controls and COPD subjects. The researchers had hypothesized that platelet indices are disturbed in COPD patients, and C-reactive protein (CRP), fibrinogen (Fbg), and white blood cells (WBC) are also increased.

The study measured platelet count (Plt) and platelet-related parameters, including mean platelet volume (MPV), platelet distribution width (PDW), plateletcrit (Pct), their ratios (MPV/Plt, MPV/Pct, PDW/Plt, PDW/Pct), platelet to lymphocyte ratio (PLR), Plt index, as well as CRP, Fbg and WBC.

“There is a need for information about changes in platelet indices in COPD patients. They are easily available in a daily laboratory routine, and if put in corresponding combinations they might achieve better predictive or diagnostic values,” the authors said. “Thrombocytosis is often followed by lymphopenia, so if the counts of platelets and lymphocytes are calculated in platelet to lymphocyte ratio (PLR), it could become more reliable in describing the inflammation status.”

A total of 109 patients with COPD were involved in the analysis, as well as 95 control subjects.

A complete blood count showed that platelet (P = .007) and PLR (P = .006) were increased, while other platelet indices were decreased in patients compared with controls. A combined model that included PLR, PDW, and WBC correctly classified 75% of cases with an area under the curve of 0.845 (0.788 — 0.892), P < .001. Comorbidities, such as cardiovascular or metabolic diseases had no effect on the parameters.

Inhaled corticosteroids/long-acting β2-agonists (ICS/LABA) therapy increased MPV and PDW values in COPD patients.

“With a combination of several different biomarkers, better clinical protocol in COPD diagnostics, therapy monitoring and defining of new phenotypes and endotypes could be achieved. When combining PLR, PDW and WBC, 75% of cases were correctly classified in this study, and a very good diagnostic power between controls and COPD subjects was accomplished,” noted the authors. “Considering many existing changes in thrombotic events, platelets could become an attractive diagnostic and therapeutic target. Another important advantage is that platelets and their indices are common, inexpensive and non-invasive tests performed routinely in everyday laboratory practice.”

The researchers conclude that while platelet indices have demonstrated the ability to be a valuable diagnostic marker, reproducibility in clinical practice must be assessed in the future.

Reference

Hlap&#269;i&#263; I, Somborac-Ba&#269;ura A, Popovi&#263;-Grle S, et al. Platelet indices in stable chronic obstructive pulmonary disease - association with inflammatory markers, comorbidities and therapy. Biochem Med (Zagreb). 2020;30(1):010701. doi:10.11613/BM.2020.010701.