ABSTRACT
Background: Impaired immune status due to altered T-cell response in sickle cell disease (SCD) might provide substantial insight into immune activity in SCD patients. Materials & methods: A total of 30 healthy control, 20 SCD patients in a crisis state and 38 SCD patients in a steady state were evaluated for T-cell subsets. Results: A significant decrease in CD8+ (p = 0.012) and CD8+45RA-197+ (p = 0.015) T-cells were observed among SCD patients. Naive T-cells (45RA+197+; p < 0.01) were elevated and effector (RA-197-) and central memory (RA-197+) T-cells were grossly reduced in the crisis state. Negative regression of naive T-cells with CD8+57+ affirmed immune inactivation. The predictor score reflected 100% sensitivity for predicting the crisis state (area under the curve = 0.851; p < 0.001). Conclusion: Monitoring naive T-cells with predictive scores can help assess the early shift from a steady state to a crisis state.
The sickle-shaped hemoglobin in sickle cell disease (SCD) patients are known to cause frequent episodes of blockage in small vessels. Repeated episodes of blockage result in tissue injury and create a state of chronic inflammation. In response, a series of inflammatory reactions initiate such that the immune response in these patients is quite altered. To understand these changes, this study was conducted to observe alterations in T-cell subtypes and gain substantial insight into immune activity in SCD patients. A total of 30 healthy control, 20 SCD patients in a crisis state and 38 SCD patients in a steady state were evaluated for T-cell subsets. The SCD patient experienced a gross decrease in T-cells with killing ability and memorizing ability for immune responses. The SCD patients in crisis state reported a significant increase in inactivated T-cells but the levels of activated T-cells that can defend and memorize the immune response were quite low. The finding suggested that this group of SCD patients had compromised immune activation that hindered the activation and differentiation of inactivated T-cells to their effector and memory cells. An equation was derived considering all the parameters that were significantly altered to derive a predictive score that showed 100% sensitivity for predicting a crisis state. Hence, it is proposed that monitoring the inactivated T-cell population or predictive score might help clinicians to assess clinical severity at an early stage and initiate appropriate preventive measures.
