To investigate the changes of bilirubin, T-lymphocyte subsets, and interleukin-6 (IL-6) levels in neonatal hyperbilirubinemia and to analyze their clinical significance in the diagnosis and treatment of this condition.

Forty newborns with hyperbilirubinemia who were hospitalized from January 2015 to December 2015 were randomly selected. According to the treatment methods used, the patients were equally divided into two groups: those undergoing conventional blue light treatment alone (group 1) and those undergoing conventional blue light plus Mamiai treatment (group 2). Twenty age-matched healthy newborns were included as a control group (no jaundice or serum bilirubin levels ≤ 205.2 μmol/ L). The T-lymphocyte subsets and IL-6 levels in peripheral venous blood samples from these neonates were measured, compared, and analyzed.

Before treatment, T-lymphocyte subsets in groups 1 and 2 were all significantly lower than those in the control group [CD3⁺ : (48.00±5.28)% vs (46.60±5.57)% vs (60.54±4.66)%; CD4⁺ : (31.05±5.09)% vs (33.50±4.80)% vs (44.86±3.75)%; CD4⁺ /CD8⁺ ratio: 0.93±0.21 vs 0.95±0.23 vs 1.32±0.17; P<0.001 for all]; IL-6 levels in groups 1 and 2 were significantly higher than those in the control group [(21.73±2.35) ng/mL vs (22.05±2.58) ng/mL vs (10.85 ±2.11) ng/mL, P<0.001]. After treatment, T-lymphocyte subsets in groups 1 and 2 were still significantly lower than those in the control group [CD3⁺ : (46.15±7.17)% vs (55.15±6.89)% vs (60.54±4.66)%; CD4⁺ : (29.45±5.64)% vs (37.85 ±5.49)% vs (44.86 ±3.75)%; CD4⁺ /CD8⁺ ratio: 0.92±0.22 vs 1.12±0.25 vs 1.32±0.17, P<0.01], and the levels of IL-6 were still higher than that of the control group [(23.83±3.34) ng/mL vs (14.91±2.31) ng/mL vs (10.85±2.11) ng/mL, P<0.01]. However, CD3⁺ , CD4⁺ , and CD4⁺ /CD8⁺ ratio were significantly higher and IL-6 level was significantly lower in group 2 than in group 1 (P<0.01). Serum total bilirubin levels were negatively correlated with CD4⁺ /CD8⁺ ratio in the hyperbilirubin groups before treatment (r=-0.780, -0.594, P<0.01), but positively correlated with IL-6 level (r=0.752, 0.591, P<0.01).

There is a disturbance of cellular immunity and cytokine secretion in neonates with hyperbilirubinemia. Phototherapy could reduce high indirect bilirubin, but it does not improve the immune function of newborns with hyperbilirubinemia. Oral immunomodulator Mamiai could effectively compensate for the deficiency of phototherapy.