Examining the lifespan of red blood cells in individuals with systemic lupus erythematosus.

ObjectiveThe objective of this study is to examine the lifespan of red blood cells (RBCs) in individuals with systemic lupus erythematosus (SLE), explore the factors influencing this lifespan, and assess its significance in clinical contexts.MethodsThe experimental group comprised of 182 patients with SLE, while the control group consisted of 90 healthy participants. By using a non-invasive breath test, we measured the RBC lifespan in both groups. Subsequently, we conducted a comparative analysis of general clinical data and laboratory findings to explore the correlation between RBC lifespan in patients with SLE and various parameters associated with RBC characteristics, inflammatory markers, and immunological indicators. Furthermore, we examined the impact of COVID-19 infection on RBC lifespan among patients with SLE and assessed the diagnostic efficacy of RBC lifespan.ResultsRBC lifespan was notably reduced in the SLE group in comparison to the healthy control group (P = 0.002). A positive correlation was observed between RBC lifespan and hemoglobin (HB), complement 3, and complement 4, whereas a negative correlation was noted with IgG, erythrocyte sedimentation rate (ESR), C-reactive protein, and anti-dsDNA levels (all P < 0.05). Noteworthy independent contributors to the reduction in RBC lifespan among patients with SLE included disease activity and presence of anemia. While RBC lifespan remained unchanged in the control group before and after COVID-19 infection (P > 0.05), a reduction in RBC lifespan post-COVID-19 infection was observed among patients with SLE (P < 0.05). Also, RBC lifespan was notably shorter during the active disease phase of SLE compared to the stable phase, with post-COVID-19 active patients with SLE exhibiting even shorter RBC lifespan compared to the pre-COVID-19 active group (all P < 0.05). An optimal cutoff for the prediction of anemia in patients with SLE on the day of assessment was determined to be 93.5 days (AUC 0.792, P < 0.05).ConclusionPatients with SLE exhibited shorter RBC lifespan in contrast to the healthy population, which is notably linked with levels of inflammatory and immune markers, as well as the incidence of COVID-19 infection. This discovery holds crucial significance for both the diagnosis of anemia and the comprehension of its underlying pathogenic mechanisms within the context of SLE.