title: The value of percentage of CD8+ T lymphocyte levels in distinguishing polymyalgia rheumatica from early rheumatoid arthritis.
abstract: OBJECTIVE
  To determine whether the low absolute numbers and percentages of CD8 positive T cells in the circulation of patients with polymyalgia rheumatica (PMR) could be used as a new diagnostic criterion for the disease.
  
  
  METHODS
  The % CD4 and CD8 positive T lymphocyte sub-populations were measured in 37 patients with PRM before treatment and during steroid treatment over the subsequent 2 years, in 21 patients with rheumatoid arthritis (RA), and in 27 normal (N) control subjects.
  
  
  RESULTS
  During the study, 10 patients, who were initially diagnosed as PMR, were reclassified as having had a myalgic onset of RA (PMR-RA), according to the American College of Rheumatology criteria for the diagnosis of RA. No decreased %CD8+ T lymphocyte subset had been observed in these patients at presentation, before steroid therapy, or during treatment with steroids when compared with the RA and N groups.
  
  
  CONCLUSIONS
  The measurement of %CD8+ T cell subset may provide a simple method for determining whether patients presenting with myalgia are "true" PMR or are destined to develop RA.
authors.affiliation: United Medical School, Division of Medicine, Guy's Hospital, London, UK.
authors.forename: V M
authors.initials: VM
authors.lastname: Corrigall
authors.forename: A L
authors.initials: AL
authors.lastname: Dolan
authors.forename: G S
authors.initials: GS
authors.lastname: Panayi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000473:pathology*; D001773:Blood Cells / Q000473:pathology*; D015496:CD4-Positive T-Lymphocytes / Q000473:pathology; D018414:CD8-Positive T-Lymphocytes / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D011111:Polymyalgia Rheumatica / Q000473:pathology*; D013997:Time Factors