3.2 Laboratory parameters
When comparing the complete blood count (CBC) parameters between the R/R HLH group and the non-R/R HLH group, no statistically significant differences were observed in hemoglobin level, white blood cell counts (WBC), absolute neutrophil counts (ANC), and platelet counts in both groups. However, the median ANC and platelet counts were lower in the R/R HLH group. The median ferritin level was non-significantly higher in the R/R HLH group at 11,152 ng/mL (IQR: 2,130 – 31,860 ng/mL) compared to 4,622 ng/mL (IQR: 1,263 – 20,001 ng/mL) in the non-R/R HLH group (p=0.241). The median serum sodium level was slightly lower in the R/R HLH group, although this difference was not statistically significant. Regarding coagulation tests, both prothrombin time (PT) and INR were significantly elevated in the R/R HLH group, along with serum aspartate aminotransferase (AST) and levels of both total and direct bilirubin. In the 67 cases with available lactate dehydrogenase (LDH) data, which included 21 R/R HLH and 46 non-R/R HLH cases, the median LDH level in the R/R HLH group was 1,168 U/L (IQR: 717 – 3,198 U/L), compared to 721 U/L (IQR: 372 – 1,429 U/L) in the non-R/R HLH group (p=0.026). When comparing the median erythrocyte sedimentation rate (ESR) in 22 patients with R/R HLH to that in 40 patients without R/R HLH, there was no statistically significant difference between these groups (32.5 mm/h (IQR: 12.0 – 58.0 mm/h) vs 47.0 mm/h (IQR: 17.0 – 76.0 mm/h), p=0.140). The median CRP levels in 20 patients with R/R HLH and 39 patients without R/R HLH were also found to be comparable (37.2 mg/L (IQR: 15.0 – 67.2 mg/L) vs 31.4 mg/L (IQR: 12.0 – 87.1 mg/L), p=0.850). Comprehensive laboratory data was presented in Table 2.