COVID-19 patients typically present with lower airway disease, although involvement of other organ systems is usually the rule. Hematological manifestations such as
thrombocytopenia and reduced lymphocyte and eosinophil numbers are highly prevalent in
COVID-19 and have prognostic significance. Few data, however, are available about the prevalence and significance of
anemia in
COVID-19. In an observational study, we investigated the prevalence, pathogenesis and clinical significance of
anemia among 206 patients with
COVID-19 at the time of their hospitalization in an Internal Medicine unit. The prevalence of
anemia was 61% in
COVID-19, compared with 45% in a control group of 71 patients with clinical and laboratory findings suggestive of
COVID-19, but nasopharyngeal swab tests negative for SARS-CoV-2
RNA (p = 0.022). Mortality was higher in SARS-CoV-2 positive patients. In
COVID-19, females had lower
hemoglobin concentration than males and a higher prevalence of moderate/severe
anemia (25% versus 13%, p = 0.032). In most cases,
anemia was mild and due to
inflammation, sometimes associated with
iron and/or
vitamin deficiencies. Determinants of
hemoglobin concentration included: erythrocyte sedimentation rate, serum
cholinesterase,
ferritin and
protein concentrations and number of
chronic diseases affecting each patient.
Hemoglobin concentration was not related to overall survival that was, on the contrary, influenced by red blood cell distribution width, age,
lactate dehydrogenase and the ratio of arterial partial
oxygen pressure to inspired
oxygen fraction. In conclusion, our results highlight
anemia as a common manifestation in
COVID-19. Although
anemia does not directly influence mortality, it usually affects elderly, frail patients and can negatively influence their quality of life.