Chronic Obstructive Pulmonary Disease and Its Effect on Red Blood Cell Indices

Abstract

Chronic obstructive pulmonary disease (COPD) constitutes a set of heterogeneous symptoms affecting millions of people worldwide. The associated comorbidities developing in COPD involve dysregulation in physiological pathways resulting from systemic inflammation in respiratory airways. In addition to mentioning the pathophysiology, stages, and consequences of COPD, this paper also defines red blood cell (RBC) indices such as hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin concentration, red blood cell distribution width, and RBC count. It explains the role of RBC indices and RBC structural abnormalities with disease severity and exacerbations in COPD patients. Although many factors have been studied as a marker of morbidity and mortality for COPD patients, RBC indices have emerged as revolutionary evidence. Therefore, the effectiveness of evaluating RBC indices in COPD patients and their importance as a negative predictor of survival, mortality, and clinical outcomes have been debated through rigorous literature reviews. Furthermore, the prevalence, mechanisms of development, and prognosis of underlying anemia and polycythemia in COPD have also been evaluated, with anemia most significantly associated with COPD. Therefore, more studies should be conducted to address underlying anemia in COPD patients to lessen the severity and disease burden. Correcting the RBC indices in COPD patients remarkably impacts the quality of life and reduces in-patient admissions, healthcare resource utilization, and costs. Hence, it is noteworthy to understand the significance of considering RBC indices while dealing with COPD patients.

Keywords: anemia of chronic disease (acd); copd: chronic obstructive pulmonary disease; rbc indices; rbc structural alterations; secondary polycythemia.

Figure 1. Pathophysiology of anemia of chronic disease in COPD

TNF-α: Tumor necrosis factor-alpha; IL-6: Interleukin-6; IL-8: Interleukin-8; IL-1β: Interleukin-1-beta; CRP: C- reactive protein; LDH: Lactate dehydrogenase; SA-A: Serum amyloid-A; SP-D: Surfactant protein-D; EPO: Erythropoietin; COPD: Chronic obstructive pulmonary disease Copyright/License: This figure is recreated using data from an open-access article distributed under the terms and conditions of the Creative Commons Attribution-Non-Commercial 4.0 (CC BY-NC 4.0) license. (http://creativecommons.org/licenses/by-nc/4.0/) Patel MS, McKie E, Steiner MC, Pascoe SJ, Polkey MI: Anaemia and iron dysregulation: untapped therapeutic targets in chronic lung disease?. BMJ Open Respir Res. 2019, 6:e000454. 10.1136/bmjresp-2019-000454 [40].

Figure 2. Representation of nine-year survival of COPD patients according to RDW in a Kaplan-Meier curve (p<0.01)

RDW: Red cell distribution width; COPD: Chronic obstructive pulmonary disease. Copyright/License: This figure is from an open-access article distributed under the terms and conditions of the Creative Commons Attribution-Non-Commercial-NoDerivatives 4.0 (CC BY-NC-ND 4.0) license. (https://creativecommons.org/licenses/by-nc-nd/4.0/) No modifications were made to the original figure. Tertemiz KC, Ozgen Alpaydin A, Sevinc C, Ellidokuz H, Acara AC, Cimrin A: Could "red cell distribution width" predict COPD severity?. Rev Port Pneumol (2006). 2016, 22:196-201. 10.1016/j.rppnen.2015.11.006 [9].