Relationship between SARC-F score and Peripheral Blood Lymphocytes in Juvenile Idiopathic Arthritis: An Observational Pilot Study

Abstract

BackgroundGiven the relatively high prevalence of sarcopenia and immune profile abnormalities in inflammatory arthritis such as rheumatoid arthritis (RA), we investigated the relationship between exercise habits, SARC-F score and peripheral blood lymphocyte profiles in patients with Juvenile idiopathic arthritis (JIA). MethodsAll participants with JIA completed the SARC-F survey and self-reported exercise habits through online questionnaires. We defined two groups based on SARC-F scores as musculoskeletal function impaired (SARC-Fhi+) and musculoskeletal function not impaired (SARC-Fhi-). We used flow cytometry of peripheral blood mononuclear cells to define immune cell subpopulations. Statistical analyses were performed using GraphPad Prism software version10. ResultsOf the 18 participants with a median age of 24 years - five belonged to the SARC-Fhi+ group and 13 to the SARC-Fhi-group, of whom 80% and 38% were female, respectively. The SARC-Fhi + group had fewer CD45RA+CD27+ naive CD4+ T cells (26.60% vs. 45.30%, p=0.0264) and greater CD45RA-CD27-effector memory CD4+ T cells (11.90% vs. 7.00%, p=0.0350). The SARC-Fhi+ group also had fewer CD56-CD16+ NK cells compared to the SARC-Fhi-group (2.60% v. 4.28%, p = 0.0194). The moderate exercise group (n = 13) had increased numbers of total CD4+ T cells (54.06% vs. 37.30%, p=0.0140) and 3-fold fewer CD45RA+CD27-EMRA CD8+ T cells (3.17% vs. 10.40%, p=0.0350). There were no other significant differences for other immune cells / subpopulations including B cells. ConclusionsOur study findings suggest notable differences in immune profile relative to SARC-F score. Furthermore, the 3-fold lower frequency of CD8+ TEMRA subpopulation of T cells, reflective of immunosenescence, suggest a potential inverse relationship between moderate exercise and peripheral immune cell profile in JIA. Key messagesO_LISARC-F score was used as a clinically relevant tool to identify musculoskeletal function in JIA C_LIO_LISARC-Fhi+ group had fewer naive CD4+ T cells and greater effector memory CD4+ T cells C_LIO_LIModerate exercise group had 3-fold lower frequency of CD8+ TEMRA T cells C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=54 SRC="FIGDIR/small/681879v1_ufig1.gif" ALT="Figure 1"> View larger version (11K): org.highwire.dtl.DTLVardef@1eb9d4org.highwire.dtl.DTLVardef@13a18a4org.highwire.dtl.DTLVardef@127d55corg.highwire.dtl.DTLVardef@28bddf_HPS_FORMAT_FIGEXP M_FIG C_FIG