Increased serum levels of interleukin 10 in Sjögren's syndrome; correlation with increased IgG1.

OBJECTIVE: To determine levels of interleukin 10 (IL-10) and IgG subclasses in serum from 53 patients with primary Sjögren's syndrome (SS). METHODS: Serum levels of IL-10 were measured using specific sandwich ELISA in 25 patients with "definite" SS, 28 with "possible" SS, and 32 healthy controls. Interferon-gamma (IFN-gamma) and transforming growth factor-beta1 (TGF-beta1) were also measured by immunoassays. Immunoglobulin classes, IgG subclasses, and C-reactive protein were measured by nephelometry. RESULTS: Circulating IL-10 was elevated in 25 patients. The increase reached significance in the group with possible SS (p = 0.03) versus controls. In the group with definite SS, IL-10 level was correlated with IgG1 level (p = 0.01, r = 0.67) and with focus score (p = 0.01). IFN-gamma was undetectable in most patients. TGF-beta1 was higher (not significantly) in possible SS than in definite SS. CONCLUSION: IL-10 is increased in SS and may account for the overproduction of IgG1 in the syndrome. High IL-10 in the absence of increased IgG1 in possible SS suggests that IL-10 may be necessary but not sufficient for IgG1 overproduction and that other factors are involved. Whereas the correlation of IL-10 level with focus score was expected, it is intriguing that IL-10 was more frequently increased in the incomplete (possible) form of SS than the complete (definite) form. Elevated IL-10 may characterize the lower stage of eccrine dysfunction and perhaps contributes to limiting its severity.

Familial alpha-1-antitrypsin dificiency with Pi-Z and a new Pi-Gcler variant.

A case of familial deficiency in alpha-1-antitrypsin connected with Pi-0Z gene led to the finding of a new Gcler variant partly deficient, the electrofocusing pattern of which, located between that of G and I variants, was modified after neuraminidase digestion. A study of three generations shows that Gcler variant is transmitter according to an autosomally codominant mode. Moreover serum trypsin inhibitory capacity and concentration of ten proteins have been measured in this family. Except the known relation between serum alpha-1-antitrypsin level and trypsin inhibitory, capacity, only serum IgA showed a significant correlation with serum alpha-1-antitrypsin in the deficient group with Pi-Z allele.

A case of slow variant bisalbuminmia: study of its composition in amino acids.

The authors report an observation of slow variant bisalbuminemia. After electrophoretic separation of two varieties, the amino acid chromatographic analysis has permitted them to show that in the slow variant the molecule of albumin has undergone a substitution of several glutamic acid residues by lysine and of several alanine residues by proline. Such an alteration poses the problem of its effect on the antigenic specificity of the molecule and that of its mechanism of production.