Diagnosis of microcytic hypochromic anemia with red blood cell survival via carbon monoxide breath-red blood cell survival

Measuring red blood cell survival (RBCS) by a carbon monoxide breath test can help diagnose and analyze disease type and progression of anemia. In this study, we reported the application of RBCS in the differential diagnosis of thalassemia and iron deficiency anemia (IDA). A total of 233 patients were selected in this study, including 48 IDA, 60 thalassemia, and 125 healthy individual controls. The endogenous alveolar CO of each subject was measured by RBCS-01 red blood cell lifespanmeter to obtain the RBCS values. The mean RBCS for mild beta-thalassemia, severe beta-thalassemia, alpha-thalassemia, IDA and the control were 67.5 +/- 22.0, 31.3 +/- 13.9, 69.3 +/- 27.7, 78.2 +/- 28.2 and 114.3 +/- 33.8 days, respectively (P<0.05). RBCS values for thalassemia and IDA patients showed obvious shorter lifespan compared to healthy controls. The cutoff points for thalassemia, IDA and control were <72.5 and <83.5, respectively. RBCS showed a strong positive correlation to red blood cells (RBC) and hemoglobin (HGB) in thalassemia patients. In IDA patients, RBCS demonstrated a moderate positive correlation with HGB, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and red cell distribution width (RDW). There were significant differences between RBCS in different types of thalassemia. RBCS by endogenous alveolar CO testing is a rapid and reliable method for the differential diagnosis of thalassemia and IDA.