Leukocyte concentrations of inpatients with anorexia nervosa

The leukocyte or white blood cell (WBC) count is a crucial clinical risk marker for anorexia nervosa (AN). Leukocytes can be further classified as granulocytes (e.g., neutrophils, eosinophils) and agranulocytes (e.g., lymphocytes, monocytes). The immature granulocyte count (IGC) has been reported to be associated with psychological stress. However, the IGC has not been investigated in people with AN yet.

We retrieved complete datasets from the Clinical Records Interactive Search (CRIS) register for 267 inpatients with AN and available leukocyte parameters (total WBC, neutrophils, eosinophils, lymphocytes, monocytes), Health of the Nation Outcome Scales (HoNOS) scores and body mass index (BMI) data at admission. In 49 of these patients, the immature granulocyte count was also available.

Leukocyte baseline levels were WBC: 4.82 × 10⁹/L ± 2.16 (standard deviation), neutrophils: 2.96 × 10⁹/L ± 1.78, eosinophils: 0.08 × 10⁹/L ± 0.1, lymphocytes: 1.46 × 10⁹/L ± 0.57, monocytes: 0.29 × 10⁹/L ± 0.14, IGC: 0.02 × 10⁹/L ± 0.07. The WBC, eosinophils, and monocytes concentration increased significantly from admission to discharge (Cohen's d = 0.27, 0.32, and 0.65, respectively, ps < 0.001). Patients showed a significant increase in BMI from 14.13 kg/m² ± 1.48 to 16.22 kg/m² ± 2.67 (Cohen's d = 0.77, p < 0.001). The HoNOS total score was not significantly associated with any of the leukocyte parameters.

In inpatients with AN, the WBC, eosinophil and monocyte count seem to increase alongside weight restoration. Leukocytes did not exhibit reliable associations with health and social functioning measures in this sample.