Complete Blood Count-Derived Inflammatory Indices Following Whole-Body Cryotherapy Combined with Kinesiotherapy Versus Kinesiotherapy Alone in Men with Ankylosing Spondylitis

Background/Objectives: The response of complete blood count (CBC)-derived inflammatory indices to whole-body cryotherapy (WBC) in ankylosing spondylitis (AS) remains unknown. This exploratory post hoc secondary analysis examined whether adding WBC to kinesiotherapy was associated with differences in these indices and explored their associations with disease activity, pain, and high-sensitivity C-reactive protein (hsCRP) levels. Prospectively collected data from 32 men with AS were analyzed. Participants were allocated by alternation, rather than randomization, to WBC combined with kinesiotherapy (WBC + K; n = 16) or kinesiotherapy alone (KT; n = 16). Methods: Prospectively collected data from 32 men with ankylosing spondylitis (AS) who participated in a prior study were analyzed. Participants were allocated to whole-body cryotherapy combined with kinesiotherapy (WBC + K; n = 16) or kinesiotherapy alone (KT; n = 16). Complete blood count parameters, high-sensitivity C-reactive protein (hsCRP) levels, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and visual analogue scale (VAS) pain scores were assessed prospectively before and after the intervention. Previously unpublished complete blood count data were used to calculate the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI) post hoc and to explore their associations with hsCRP, BASDAI, and VAS pain. The primary intervention effects were assessed using baseline-adjusted analysis of covariance, and the five treatment-effect p-values were subjected to Benjamini–Hochberg correction. Comparisons of changes from baseline were performed as sensitivity analyses. Results: None of the baseline-adjusted between-group treatment effects for NLR, PLR, MLR, SII, or SIRI were statistically significant before or after false discovery rate correction. The adjusted between-group difference for MLR was −0.033 (95% confidence interval: −0.074 to 0.008; p = 0.115; q = 0.329). In the change-score sensitivity analysis, the between-group difference in MLR change was nominally significant (p = 0.012) but did not meet the multiplicity-adjusted significance threshold (q = 0.060). Within the WBC + K group, PLR, MLR, and SIRI decreased significantly, whereas no corresponding within-group changes were observed in the KT group; however, these within-group findings were descriptive and did not establish an additional effect of WBC. Changes in the indices were not significantly correlated with changes in hsCRP, BASDAI, or VAS pain. None of the exploratory post-treatment correlations remained significant after multiple-testing correction. Conclusions: This study did not provide baseline-adjusted or multiplicity-adjusted evidence that adding WBC to kinesiotherapy affected any of the investigated CBC-derived inflammatory indices in men with AS. The nominal MLR signal identified in the change-score sensitivity analysis and the within-group reductions in PLR, MLR, and SIRI should be considered exploratory and hypothesis-generating. Larger, prospectively designed, adequately powered randomized studies with prespecified outcomes and baseline-adjusted analyses are required.