[Study of lymphocyte subpopulations in chronic autoimmune inflammatory rheumatic diseases. I) Polymyalgia rheumatica]

The polymyalgia rheumatica (PMR) is a chronic autoimmune inflammatory rheumatic disorder, characterised by pain and stiffness on the shoulder and pelvic girdles, increasing of erythrocyte sedimentation rate (ESR) and good clinical and laboratory recovery by steroid therapy with a good outcome of the disease. There is now a wide agreement about an alteration of the distribution of lymphocyte subpopulations, characterised by a decreasing of CD8+ subset, at the onset of PMR. The aim of this paper is to study the distribution of lymphocyte subpopulations and their soluble receptors and the distribution of CD4+ and CD8+ subsets in patients with active PMR.

Forty-eight patients (9 males and 39 females, mean age 69.4+/-6.5 years) with active PMR (ESR 74+/-18 mm, 1st hour) were studied. In order to determine the distribution of lymphocyte subpopulations a panel of monoclonal antibodies was utilised. Flow cytometry was performed with a FACSCAN machine.

The absolute number of CD4-/CD8+ cells were reduced (p<0.05) in comparison to normal subjects (356+/-112/ml vs 564+/-132/ml); the reduction was due to a decrease (p<0.001) of CD8+bright cells (224+/-86/ml vs 426+/-124/ml) and of CD8+bright/CD57- subset (123+/-44/ml vs 256+/-58/ml); an increase (p<0.001) of sCD8 (514+/-123 U/ml vs 312+/-102 U/ml) and an increase (p<0.0005) of sIL-2r (984+/-346 U/ml vs 244+/-58 U/ml) were also observed in comparison to normal subjects. No alterations of CD4+/CD8, CD8+bright/CD57+, CD8+dim/ CD57+/- cells and sCD4 were observed.

Our study seems to confirm that in early and active PMR there are significant alterations of lymphocyte subpopulations and their subsets as well as of soluble receptors.