Expression of CD57 on CD8+ T lymphocytes of patients with Wegener's granulomatosis and microscopic polyangiitis: evidence for continuous activation of CD8+ cells.
OBJECTIVE
To gain insight into the immune pathogenesis of Wegener's granulomatosis (WG) and microscopic polyangiitis (MPA), the prevalence of circulating CD8+ T lymphocytes expressing CD57 as a marker for previous activation was analyzed.


METHODS
Receptor expression of CD57 was measured in CD8+ T cells of patients with active disease (n=5) by cytofluorometry and compared with expression in patients in remission (n=80) and in age-matched healthy donors (n=34). The results were compared to clinical parameters including severity and duration of the disease.


RESULTS
CD8+CD57+ were detected in patients with WG and MPA and in healthy donors as well and increased considerably with age. Compared to age-matched healthy donors, the prevalence of CD8+CD57+ was increased in the younger patients (up to 40 y). In most patients a high percentage of CD8+CD57+ coincided with severe disease and multiple organ involvement, while low CD8+CD57+ percentage was seen in patients with limited disease or in patients in complete remission. In patients with smoldering disease, the percentage of CD8+CD57+ increased with time. High numbers of CD8+CD57+ correlated with low CD4:CD8 ratio.


CONCLUSIONS
In patients with WG and MPA a population of CD8+CD57+ expand, identifying terminally differentiated CD8+ cells. The prevalence of CD57+ cells was related to the course of disease. So far, the function of CD57 on CD8+ cells is not understood. However, these cells might produce certain cytokines, which play a role in the pathogenesis of AAV. The data support the hypothesis that CD8+ T cells are activated in the context of primary vasculitides.
Iking-Konert
C
C
Rheumatology, Department of Endocrinology, Diabetology and Rheumatology, Heinrich-Heine University of Düsseldorf, Germany. christof.iking-konert@roche.com
Vogl
T
T
Prior
B
B
Bleck
E
E
Ostendorf
B
B
Andrassy
K
K
Schneider
M
M
Hänsch
G M
GM
D000328:Adult; D000368:Aged; D018959:CD57 Antigens / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism*; D005434:Flow Cytometry; D014890:Granulomatosis with Polyangiitis / Q000097:blood / Q000276:immunology* / Q000473:pathology; D006801:Humans; D008213:Lymphocyte Activation; D055953:Microscopic Polyangiitis / Q000097:blood / Q000276:immunology* / Q000473:pathology; D008875:Middle Aged
D018959:CD57 Antigens