Association of the complement allele C4AQ0 with primary Sjögren's syndrome in Japanese patients

Biochemical deficiency of pyridoxine does not affect interleukin-2 production of lymphocytes from patients with Sjögren's syndrome

BACKGROUND

There is evidence that pyridoxine deficiency may alter the immune response. It is not known whether a deficiency of this vitamin is evident in subjects with primary Sjögren's syndrome (SS).

OBJECTIVE

We studied whether subjects with primary SS showed a biochemical deficiency of pyridoxine, and if it is associated with abnormal production of interleukin-2 from lymphocytes stimulated in vitro with phytohemagglutinin (PHA).

DESIGN

Two studies were conducted, (i) biochemical and nutritional assessments were performed in a cross-over study in subjects with primary SS, who were supplemented with 25 mg/day of pyridoxine or placebo for 3 months. After 1 month washout, they were supplemented for 3 months with placebo, (ii) patients with SS and matched controls received pyridoxine or placebo for 45 days, and a blood sample was obtained to study IL-2 production and expression in T-lymphocytes stimulated with PHA.

RESULTS

Subjects with primary SS showed limited dietary intake of pyridoxine and biochemical deficiency of this vitamin assessed through the activation coefficient of the erythrocyte aspartate aminotransferase. The biochemical deficiency did not affect production nor mRNA expression of IL-2 from T-lymphocytes stimulated in vitro with PHA compared with the control group. Supplementation of subjects with primary SS with 25 mg/day with pyridoxine for 45 days did not produce any significant change as compared to those patients supplemented with placebo.

CONCLUSIONS

Subjects with primary SS showed biochemical deficiency of pyridoxine, possibly due to limited intake of this vitamin which was corrected by supplementation with pyridoxine. However, IL-2 production and mRNA expression from stimulated lymphocytes were unaffected by supplementation, probably because the deficiency was not severe enough to affect the immune system.

SPONSORSHIP

This work was supported by the National Council of Science and Technology (CONACYT), Mexico, grant no. 212226-5-0902PM.

Genetic deficiencies of complement

Genetic deficiencies of proteins of the complement system are associated with diverse clinical phenotypes. These clinical manifestations vary as a function of the specific component that is missing. Molecular and cellular biological methods, coupled with more intensive clinical studies, have defined the pathophysiological basis for this set of genetic disorders. Insights into the normal function of complement and its role in immunopathology have been derived from the extensive work in this field during the past few years.

Major histocompatibility complex genes and susceptibility to systemic lupus erythematosus in northern India

Fifty-eight patients with systemic lupus erythematosus (SLE) from Northern India were tissue typed for HLA class I and II antigens. The results revealed an appreciable increase of HLA-DR4 (37.5%) among patients compared with controls (17.9%), P < 0.03. Additionally, haplotype B8-DR3 was encountered frequently in the patient group. The findings suggest an important role of MHC genes in influencing susceptibility to SLE.

Linkage studies of HLA and primary Sjögren's syndrome in multicase families

OBJECTIVE

To define the role of HLA-DR phenotype in the expression of primary Sjögren's syndrome (SS).

METHODS

A family study of Caucasian probands with definite primary SS was conducted. Relatives with features of primary SS were classified according to the Fox criteria. Several types of linkage analysis between primary SS and HLA haplotype (HLA-A, B, and DR) were performed.

RESULTS

A trend toward haplotype sharing between affected siblings was evident for definite/probable primary SS when analyzed by the Green and Woodrow method. This reached statistical significance when data from other published family studies were included. LOD scores and analyses using the Penrose method showed little evidence of linkage.

CONCLUSION

In view of the strong association with HLA-DR3, these results suggest that the HLA-DR3 allele is an important susceptibility factor for expression of primary SS in Caucasians. The apparent haplotype sharing may be a consequence of this association. The potential influence of other genetic factors (major histocompatibility complex [MHC] and non-MHC) is discussed.