Existing Tubular Injury in β-Thalassemia Major Patients Receiving Iron Chelating Agents with Normal Creatinine Level in East Java, Indonesia

Patients suffering from thalassemia are recipients of routine transfusions leading to hemosiderosis. Taking iron chelating agents is mandatory. Several studies have shown different results regarding the occurrence of kidney complications in thalassemia patients who received iron-chelating agents. In this study, we were looking for kidney complications by examining human NAG urine/serum and NGAL urine/serum in thalassemia community in East Java community. The study was conducted cross-sectionally in the thalassemia community in East Java with a total sample of 91 patients aged 13-48 years. All thalassemia patients filled in demographic data, transfusion routines, duration of taking iron chelating agents, and length of time diagnosed with thalassemia. Laboratory tests included routine blood tests for ferritin, ureum, serum creatinine, human NAG urine or serum, and human NGAL urine or serum. Comparison tests (<i>t</i>-test, Mann-Whitney, and ANOVA, Kruskal-Wallis) were conducted to see if there were significant differences in the levels of human NAG urine and human NGAL urine serum based on age, sex, blood group, duration of transfusion, routine of transfusion, duration of taking iron chelating agents, and types of iron chelating drugs. Multivariate analysis was conducted to see whether some of these categories were related to abnormalities in human NAG urine or serum and human NGAL urine or serum. All 91 patients had normal creatinine values, yet some had abnormal serum NAG. There is a significant difference in urine human NAG and urine human NGAL levels at ages over 23 years (<i>p</i> = 0.05 and <i>p</i> = 0.01). Significant differences in human NGAL serum were also found in working and student patients (<i>p</i> = 0.028). Serum NGAL also differed in those taking deferasirox (<i>p</i> = 0.030) and significantly different human NGAL urine was also found in iron overload status (Ferritin ≥ 1000 ng.ml) (<i>p</i> = 0.006). There is no difference between human NAG urine/serum and human NGAL urine/serum based on sex, body mass index, blood type, hemoglobin less than 10 g/dl, routine transfusion once a month, duration of using iron chelation for more than 10 years, or splenomegaly status (splenomegaly, splenectomy, or no splenomegaly). The multivariate logistic regression results showed that age above 23 was a factor associated with abnormal urine human NAG levels (aOR = 3.79, 95% CI = 1.08-13.28). Students (aOR = 4.89, 95% CI = 1.48-16.16) with ages above 23 years (aOR = 3.69, 95% CI = 1.09-12.43) showed higher risk for an abnormal serum human NGAL levels. Patients with beta-thalassemia major exhibit noticeable tubular damage. Further research is encouraged to determine other factors behind tubular damage in the thalassemia community, particularly in Indonesia.