Original Research ARTICLE
Leukocyte Dynamics Reveal a Persistent Myeloid Dominance in Giant Cell Arteritis and Polymyalgia Rheumatica
- 1University Medical Center Groningen, Netherlands
Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are inflammatory diseases requiring long-term glucocorticoid treatment. Limited data on dynamics in leukocyte counts before, during and after treatment are available. Leukocyte counts were measured, as cellular markers of inflammation, at fixed time points in our prospectively studied cohort of pre-treatment glucocorticoid-naive GCA (N=42) and PMR (N=31) patients. Values were compared with age-matched healthy controls (HCs; N=51) and infection controls (N=16). We report that before start of treatment monocyte and neutrophil counts were higher in GCA and PMR patients than in HCs, while NK- and B-cell counts were lower. C-reactive protein (CRP) levels correlated positively with monocyte counts in GCA, and negatively with B-cell and NK-cell counts in PMR. During glucocorticoid treatment, myeloid subsets remained elevated whereas lymphoid subsets tended to fluctuate. Interestingly, erythrocyte sedimentation rate (ESR) outperformed CRP as marker for relapses in GCA. We defined stable treatment-free remission groups in both GCA and PMR. GCA patients in treatment-free remission still demonstrated elevated monocytes, neutrophils, ESR and platelets. PMR patients in treatment-free remission had normalized levels of inflammation markers,, but did have elevated monocytes, lowered CD8+ T-cell counts and lowered NK-cell counts. Finally, we showed that low hemoglobin level was predictive for long-term GC treatment in PMR. Overall, leukocyte composition shifts towards the myeloid lineage in GCA and PMR. This myeloid profile, likely induced by effects of inflammation on hematopoietic stem cell differentiation, persisted during glucocorticoid treatment. Surprisingly, the myeloid profile was retained in treatment-free remission, which may reflect ongoing subclinical inflammation.
Keywords: Giant cell arteritis (GCA), Polymyalgia rheumatica (PMR), Vasculitis, Gluococorticoid therapy., longitudinal analysis, Treatment-free remission (TFR)
Received: 13 Mar 2019;
Accepted: 05 Aug 2019.
Edited by:Pier Luigi Meroni, Italian Auxological Institute (IRCCS), Italy
Reviewed by:Michael Schirmer, Innsbruck Medical University, Austria
Peter M. Villiger, Department of Rheumatology, Immunology and Allergology, Bern University Hospital, Switzerland
Copyright: © 2019 van Sleen, Graver, Abdulahad, van der Geest, Boots, Sandovici and Brouwer. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Mr. Yannick van Sleen, University Medical Center Groningen, Groningen, Netherlands, email@example.com