Circulating CD8 T Cells in Polymyalgia Rheumatica and Giant Cell Arteritis: A Review Victor M. Martinez-Taboada, Ricardo Blanco, Concepcio ´nFito, Maria Jose Bartolome Pacheco, Miguel Delgado-Rodriguez, and Vicente Rodriguez-Valverde Background and Objective: During the last few years, there have been several studies on T cell subsets in polymyalgia rheumatica (PMR) and giant cellarteritis(GCA),withconflictingresults.Whereassomeauthorshavefound normal values of circulating CD8T cells, others have found a decreased number.Furthermore,insomestudies,thelevelofCD8cellswasfoundtobe related to disease activity, and it has been proposed that a decrease of CD8 TcellsbeusedasadiagnosticcriterionforPMR.Thepurposeofourstudywas to determine the value of assessing T cell subsets in PMR and GCA. Methods: Tlymphocytesubsetsweredeterminedbyflowcytometryusinga whole blood lysis technique in the following groups: 28 PMR and 6 GCA patients before corticosteroid treatment, 20 PMR and 12 GCA patients in clinical remission with steroid treatment, 55 PMR patients in remission with- out steroid treatment, 17 rheumatoid arthritis (RA) patients before treatment, and 18 age-matched controls with noninflammatory conditions. Total white cell, lymphocyte, and platelet counts, hemoglobin, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were measured by routine tech- niques. Comparisons were made by the Student’s t-test and the Mann-Whit- ney test. A MEDLINE database search for studies published between 1983 and 1997 was performed. Results: Compared with noninflammatory controls, CD8T cells were not reduced before steroid treatment in patients with active PMR/GCA in propor- tion (P .7) or absolute numbers (P .1). Patients with active disease had significantlylowerhemoglobinlevelsandhigherplateletcounts,CRP,andESR than noninflammatory controls (P < .05). When compared with active RA, CD8T cells were not reduced in patients with active PMR in proportion (P .5)orabsolutenumbers(P .2).Betweenthesetwogroups,RApatientswere significantly younger (P .003) and had lower ESR values (P .003). We did not find significant differences between patients with active PMR/GCA and those in remission with steroid therapy, except for the lower hemoglobin levelsandhigherplateletcount,CRP,andESRintheactivediseasegroup(P < .05). The same results were found when patients with active disease were From the Rheumatology Division, Hospital Universitario “Marque ´s de Valdecilla,” Facultad de Medicina, Universidad de Cantabria, Santander, Spain, and the Division de Medicina Preven- tiva y Salud Publica, Universidad de Jae ´n. Victor M. Martı ´nez-Taboada, MD: Staff Physician, Rheumatol- ogy Division; Ricardo Blanco, MD: Staff Physician, Rheumatology Division; Concepcio ´n Fito, MD: Former fellow; Vicente Rodrı ´guez- Valverde, MD: Professor of Medicine and Chair, Rheumatology Division; Maria J. Bartolome Pacheco, MD: Fellow in Immunol- ogy, Hospital Universitario “Marque ´s de Valdecilla,” Facultad de Medicina, Universidad de Cantabria, Santander, Spain; Miguel Delgado-Rodriguez, MD: Professor of Medicine, Divisio ´n de Me- dicina Preventiva y Salud Pu ´blica, Universidad de Jae ´n. Supported by a grant from “Fundacio ´n Marque ´s de Valde- cilla” 1996 and 1998, a grant of “Caja Cantabria” 1996, and Fondo de Investigacio ´ n Sanitaria (98/0846). C. Fito was supported by a grant of “Fundacio ´n Marque ´s de Valde- cilla.” Address reprint requests to Victor M. Martı ´nez-Taboada, MD, Rheumatology Division, Hospital Universitario “Marque ´s de Valdecilla,” Avenida de Valdecilla s/n, 39008 Santander, Spain; E-mail: vmartinezt@medynet.com Copyright © 2001 by W.B. Saunders Company 0049-0172/01/3004-0921$35.00/0 doi:10.1053/sarh.2001.9734 257 Seminars in Arthritis and Rheumatism, Vol 30, No 4 (February), 2001: pp 257-271