Association of Clinical and Paraclinical Factors with Pain Crisis Severity in Sickle-Thalassemia Patients in Iran

Abstract

Objectives: This study aimed to evaluate the effects of several factors, including hospitalization frequency, inflammatory and hemolytic markers, and the numbers of blood transfusions and crises, on the severity of pain crises in sickle-thalassemia patients. Methods: Of all patients visiting hematologists in university-affiliated hospitals and clinics, only 75 sickle cell disease (SCD) and sickle-thalassemia patients met the inclusion criteria for this study. Disease severity was measured based on pain crises per year and laboratory markers, including hemolytic and inflammatory indicators, outpatient or inpatient status, the number of hospital admissions, and the number of blood units transfused over one year. Results: In sickle cell patients, a significant correlation was observed between hospital admission and WBC (0.01), ALP (0.001), MCHC (0.001), ferritin (0.021), and ESR (0.006). Additionally, pain crises were positively correlated with transferrin saturation (TS) (+0.28) and the number of transfused blood units (+0.49) and negatively correlated with Hb (-0.30) and total iron binding capacity (TIBC) (-0.23). Blood unit transfusions showed a positive correlation with serum iron (+0.44), RDW (+0.36), ferritin (+0.39), pain crises (+0.49), and TS (+0.49), along with a negative correlation with Hb (-0.75) and MCHC (-0.33). When categorizing pain crises into two groups, patients experiencing more frequent crises generally exhibited lower hemoglobin levels and a higher number of blood units transfused. Hemoglobin also showed a significant negative correlation with lactate dehydrogenase (LDH) level in both groups: -0.604 (P = 0.005) in patients with ≥ 3 crises per year and -0.368 (P = 0.006) in patients with < 3 crises per year. Patients with hemoglobin levels of 7.5 or higher tended to maintain an LDH level below 1000. Among patients referred with pain crises, hemoglobin was negatively correlated with hemolytic markers such as LDH (-0.41) and retic (-0.29). Conclusions: Hemoglobin and LDH can serve as follow-up markers, as they are routinely measured in all sickle cell patients and, in this study, hemoglobin levels of 7.5 or higher and LDH levels below 1000 were associated with fewer and less severe pain crises. Regular monitoring of hemolytic markers may help in pain crisis prevention, as this study found that hemolytic crises frequently coincided with pain crises. Further research is needed to provide conclusive evidence in this area.