Macrocytosis in COPD and Course of the Disease

INTRODUCTION: Macrocytosis (MCV>94fl) is frequently observed at patients suffering from chronic obstructive pulmonary disease (COPD) with or without respiratory insufficiency. Recent studies have demonstrated the role of erythropoietin massive excretion subsequent to hypoxemia as a trigger factor in excessive marrow erythropoiesis. Thus, a large number of immature red cells are released in peripheral blood leading to macrocytosis. AIM: To determine possible correlation between macrocytosis and severity of he disease in patients with COPD.

PATIENTS AND METHODS: Thirty eight patients (mean age: 62,16±10,88 years, twenty nine male-Group A and nine female-Group B) with COPD were attended regarding their clinical status for one year, diagnosed according to spirometric classification of COPD based on post-bronchodilator FEV1 (Global Initiative for Chronic Obstructive Lung Disease, 2006). All patients were smokers suffered from mild or moderate COPD (FEV1/FVC <0,70, FEV1≥50% predicted, with PaO2 more than 60mmHg). MCV and hematocrit were measured separately for male and female additionally to the whole sample. Exacerbations considered to be happen when dyspnea or PaO2<60mmHg occurred. Patients with anemia, hematological malignancy, hypothyroidism, heart or renal failure and diabetes mellitus excluded.

RESULTS: Mean value for MCV was 98,84±2,66 fl (range:95–107 fl). Average for Group A estimated at 99,52±2,92 (range: 95–107) and for Group B at 96,87±1,40 (range: 95–99). Mean value of exacerbations for both groups in one’s year period was 0,89±0,61 (range :0–2), that was not significantly different from those concerning Group A and Group B (0,79±0,60, 1,22±0,74 respectively). Inverse correlation between MCV and number of exacerbations was statistically significant (r = − 0,43, p<0,01). That correlation was more apparent for Group A (r = −0,45, p<0,01) than Group B (r = −0,35, p<0,05). Mean value of hematocrit was determined at 45,92 ± 3,77 (range: 40–54). Correlation between MCV and Ht was not significant (r=0,2).

CONCLUSIONS: An unexpected result revealed considering that elevated MCV in patients with mild to moderate COPD correlates with fewer exacerbations of the disease. A game of statistics or something more important for the pathophysiology of mild COPD?