Memory B-cell aggregates in skin biopsy are diagnostic for primary Sjögren's syndrome.

There is a crucial need for reliable diagnostic criteria for SS. Our objective was to evaluate the frequency of xerosis in patients with primary Sjögren's syndrome (SS), and compare histopathology of cutaneous sweat glands and labial salivary glands (LSGs), with respect to their contribution to the diagnosis. Twenty-two patients with primary SS and 22 matched normal volunteers were invited to rate their skin dryness on a visual analog scale. The skin was dryer (58.3 ± 10.1 versus 38.9 ± 7.6, P < 0.01), and xerosis more frequent (9 of 22 versus 2 of 22, P < 0.02) in the patients than in the controls. The axilla skin was chosen for a 6-mm punch biopsy. Lymphocytic infiltration was seen in the skin of 8 of the 12 patients tested. Two of them had normal LSGs. Most interestingly, B cell infiltrates were identified in patients' skin infiltrates, so that their presence might be a clue to the diagnosis of primary SS. These cell aggregates associated memory CD10-/CD20+/CD27+/IgD- B lymphocytes and immature CD20+/CD24 + lymphocytes. These latter findings strongly suggest that skin biopsies warrant inclusion into the routine clinical care of patients suspected of suffering from primary SS.