Functional features of neutrophils in subclinical hypothyroidism compared to euthyroid status

Abstract

Neutrophils or polymorphonuclear leukocytes are critical to host defense against pathogens. Increasing evidence indicates that thyroid hormones also play an active role in immune mechanism while there is very little literature regarding effects of thyroid stimulating hormone on functional features of neutrophils. In this cross-sectional study, we evaluated the phagocytic, chemotactic, candidacidal, and respiratory burst activity of neutrophils in subclinical hypothyroid and euthyroid subjects. Phagocytosis and metabolic function of the neutrophils was assessed using Nitro-blue tetrazolium test. Chemotaxis, directional movement of the PMNs was measured using the N-Formyl methionyl-leucyl-phenylalanine as chemoattractant. Phagocytic activity was evaluated by exposing leukocytes to candida suspension and counting the number of candida ingested and killed. Microbicidal activity of neutrophils was assessed by the ability of leukocytes to kill Candida albicans in both subclinical hypothyroid and euthyroid subjects. Our study demonstrated that chemotactic and mean phagocytic activity was significantly less in those with subclinical hypothyroidism as compared to euthyroid control group (p = 0.005 and 0.045 respectively). Respiratory burst activities of both unstimulated and stimulated neutrophils were relatively reduced in subclinical hypothyroidism (p value of 0.08 and 0.07). Candidicidal activity was similar in both groups. We conclude that a raised TSH level is associated with altered functional characteristics of neutrophils.

Measurement of the Neutrophils Count and Oxidative Burst in Neutrophils of Patients with Sanjad Sakati Syndrome

“…According to one study, there is no obvious reduction of phagocytic activity of neutrophils in hypothyroid individuals when compared to euthyroid controls. 27 This conflicting activity could be because of different methods and different cell populations studied. Our data demonstrated that the NLR index is decreased in patients diagnosed with SSS compared to the healthy subjects.…”