Nitroblue tetrazolium test in patients with beta-thalassemia major

OBJECTIVE: To assess the neutrophil function in thalassemia major (TM) patients and compare it with the control group, and to recognize its relevant factors.

METHODS: This was a retrospective cohort study, which was carried out from October 2007 to February 2008 in the Thalassemia Research Center in Boo Ali Sina Hospital in Sari, Mazandaran, north of Iran. The study population consisted of TM patients in Boo Ali Sina Teaching Hospital. The method of sampling in the case group was systematic, and it was target based in the control group. The sample size determined was based on previous studies. Thalassemia major was diagnosed based on hemoglobin electrophoresis (case group). The control group was their brothers and sisters, who had ±5 years of age difference, and were of the same gender as the patients. Data collection was based on interview, investigating demographic characteristics, and also obtaining medical information from the medical records of the patients. The neutrophil function was assessed by performing nitroblue tetrazolium (NBT) reduction test. The test was carried out on both groups, and the data were analyzed by software using SPSS version13.0.

RESULTS: In this study, 39 patients and 39 healthy controls were compared. The average age of the patients was 21.6 ± 5.3 years, and it was 22.4 ± 5.1 years in healthy controls (p=0.7). There was a significant correlation between the tests' results, and the patients' age (p=0.008). The rate of impaired NBT results in the patients was 36%, while it was 10% in controls, which were significantly different. The neutrophil activity based on NBT test was 89.9 ± 11.6% in the case group, and 93.7 ± 2.51% in the control group, (p=0.025).

CONCLUSION: This study indicates that neutrophil activity in thalassemic patients was significantly lower, compared to the normal control group, especially in young patients. Based on the results, evaluation of neutrophil function, and pyogenic infections in TM patients seems necessary.