The relationship between serum interleukins and T-lymphocyte subsets in patients with severe acute respiratory syndrome

To observe the changes of serum interleukins (IL), T-lymphocyte subsets, and white blood cell (WBC) count in patients with severe acute respiratory syndrome (SARS), and to investigate the relationship between injured immune function, immune response and disturbed immune adjustment in SARS patients. The levels of serum IL-2, IL-10, IL-12 and T-lymphocyte subset counts were measured in 35 clinically diagnosed SARS patients by using enzyme linked immunosorbant assay (ELISA). The relationship between the measured results and WBC count was further analyzed. The level of serum IL was increased to a great extent in the 35 SARS patients, and the levels of serum IL-2, IL-10 and IL-12 were 242.53 (92.69) pg/ml, 77.43 (63.37) pg/ml and 65.94 (43.21) pg/ml, respectively. The level of serum IL-2 increased markedly (P < 0.01). The peripheral blood CD(3)(+), CD(4)(+) and CD(8)(+) counts were lower than normal in 23 patients (67.7%), 26 patients (74.3%) and 15 patients (42.9%), respectively. The peripheral blood WBC counts were lower than 4.0 x 10(9)/L in 10 patients, and their CD(3)(+), CD(4)(+) and CD(8)(+) counts were 583.90 (315.58) x 10(6)/L, 272.00 (94.13) x 10(6)/L and 209.00 (72.21) x 10(6)/L, respectively. The peripheral blood WBC counts were (4.0 - 10.0) x 10(9)/L in 20 patients, and their CD(3)(+), CD(4)(+) and CD(8)(+) counts were 700.00 (502.96) x 10(6)/L, 347.00 (247.58) x 10(6)/L and 322.05 (228.47) x 10(6)/L, respectively. The peripheral blood WBC counts were higher than 10.0 x 10(9)/L in 5 patients, and their CD(3)(+), CD(4)(+) and CD(8)(+) counts were 1466.00 (630.86) x 10(6)/L, 783.00 (311.14) x 10(6)/L and 640.00 (294.40) x 10(6)/L, respectively. The decreased CD(3)(+), CD(4)(+) and CD(8)(+) counts were consistent with the decreased WBC counts. The level of IL in SARS patients was significantly higher than that in patients with chronic hepatitis B (P < 0.01). The level of serum IL is closely related to cell immunity in SARS patients. The level of serum IL is increased evidently while CD(3)(+), CD(4)(+) and CD(8)(+) counts decrease. Both serum IL and CD are associated with injury of immune function, and thus they could be regarded as a monitoring index for judging the condition of SARS patients and prescribing immune therapy.