Vitamin D levels reverberate in monocytes modulation in hemodialysis patients.

BACKGROUND: Patients with chronic kidney disease (CKD) have a severe vitamin D deficiency and increasing epidemiological data suggesting that this deficiency may play a role in overall morbidity and mortality associated with CKD. It is known that vitamin D regulates the immune system, however, in dialysis patients this deficiency and the modulation of proinflammatory cells is unclear. Among these, monocytes arouse interest considering they constitutively express vitamin D receptors.

AIM: This study aimed the evaluation of monocytic profile in CKD patients according to vitamin D levels.

METHODS: Patients in hemodialysis (HD) were divided into two groups, regarding vitamin D levels: Group 1, vitamin D <26 ng/ml (n = 15) and Group 2, vitamin D ≥26 ng/ml (n = 18). Whole blood was collected aiming evaluation of (a) monocytic populations through CD14 and CD16 expression, (b) reactive oxygen species (ROS) generation, and (c) apoptosis.

RESULTS: We observed that in Group 1, when compared to Group 2, there was a significant increase in intermediate monocytes (CD14++ CD16 + ; 34.7 ± 31.6 vs. 12.1 ± 6.3; p = 0.006, respectively) and decrease in classical ones (CD14 ++ CD16 - ; 45.3 ± 31.8 vs. 70.4 ± 25.1; p = 0.017, respectively). There was no difference between groups regarding nonclassical monocytes (CD14 + CD16 ++ ), as well as to apoptosis and to ROS generation.

CONCLUSION: This study suggests that HD patients with lower vitamin D levels might have an intensified inflammatory outline as intermediate monocytes with an inflammatory pattern are increased in this population, when compared with patients with higher levels of vitamin D.