The contribution of antiphospholipid antibodies to organ damage in systemic lupus erythematosus

OBJECTIVES

The objective of this study was to assess the contribution of clinically significant antiphospholipid antibodies (aPL) to organ damage in systemic lupus erythematosus (SLE).

METHODS

Patients with disease duration of less than 10 years and at least 5 years of follow-up were identified from two SLE registries. A clinically significant antiphospholipid antibody (aPL) profile was defined as: positive lupus anticoagulant, anticardiolipin IgG/M ≥ 40 G phospholipid units (GPL)/M phospholipid units (MPL), and/or anti-β2-glycoprotein-I IgG/M ≥ 99th percentile on two or more occasions, at least 12 weeks apart. Organ damage was assessed by the Systemic Lupus International Collaborating Clinics Damage Index (SDI). Univariate and multivariate analysis compared SLE patients with and without SDI increase during a 15-year follow-up.

RESULTS

Among 262 SLE patients, 33% had a clinically significant aPL profile, which was associated with an increased risk of organ damage accrual during a 5-year follow-up in univariate analysis, and during a 15-year follow-up in the multivariate analysis adjusting for age, gender, race, disease duration at registry entry, and time. In the multivariate analysis, older age at diagnosis and male gender were also associated with SDI increase at each time point.

CONCLUSION

A clinically significant aPL profile is associated with an increased risk of organ damage accrual during a 15-year follow-up in SLE patients.

Phenotype modifications of T-cells and their shift toward a Th2 response in patients with systemic lupus erythematosus supplemented with different monthly regimens of vitamin D

BACKGROUND

Vitamin D receptor is constitutively expressed on the lymphocyte surface. Recent studies highlight that vitamin D may exert actions on T-cells, inhibiting Th1 and Th17 response and enhancing Th2 and T-regulatory (T-reg) function.

METHODS

Thirty-four patients with systemic lupus erythematosus (SLE) were randomly enrolled in a two-year prospective study. In the first year, 16 patients were supplemented with an intensive regimen of cholecalciferol (IR) (300.000 UI of cholecalciferol at baseline and 50.000 UI/monthly as maintenance, 850.000 UI annually), whereas 18 with a standard regimen (SR) (25.000 UI of cholecalciferol monthly, 300.000 UI annually). During the second year, patients were switched to the other arm of treatment. Phenotypic analysis of peripheral T lymphocyte and the quantification of cytokine production from peripheral blood mononuclear cells (PBMCs) were evaluated by flow cytometry.

RESULTS

At baseline, no significant difference between the two groups emerged among main T-cell subtypes. Over two years of treatment, we saw an increase in the number of T-reg cells, in the total amount of CD4+CD45RA+CCR7- T-cells, whereas a significant reduction of CD8+CD28- T-cells was observed. In addition, the analysis of PBMCs from eight patients following the IR showed the reduction of the IFN-γ/IL-4 ratio (p = 0.01) among CD8+ T-cells after 12 months.

CONCLUSIONS

After a long-term of monthly treatment with vitamin D in SLE patients, an enhancement of T-reg cells and the production of Th2 cytokines should be expected.

A 24-month prospective study on the efficacy and safety of two different monthly regimens of vitamin D supplementation in pre-menopausal women with systemic lupus erythematosus

BACKGROUND

Low vitamin D (vit.D) serum levels are common in patients with systemic lupus erythematosus (SLE) and seem to correlate with higher disease activity. We investigated the effects of different regimens of vit.D supplementation in SLE patients with inactive disease.

METHODS

This 24-month prospective study included 34 SLE women who were randomized to receive, together with their ongoing treatment, a standard regimen (SR) of cholecalcipherol (25,000 UI monthly) or an intensive regimen (IR) (300,000 UI initial bolus followed by 50,000 UI monthly) for one year and then were switched to the other regimen in the second year. Patients were seen quarterly for assessment of 25-OH vit.D levels, disease activity, SLE serology and bone metabolism markers.

RESULTS

By intra-patient comparison, only the IR was found able to significantly raise vit.D serum levels. After 12 months, values above 30 ng/ml were found in 75% of patients in IR while in only 28% in SR. No significant differences in disease activity and SLE serology were found at any time point between SR and IR. No changes in the mineral metabolism were observed.

CONCLUSIONS

The IR was safe and effective in obtaining sufficient levels of vit.D in most SLE patients. However, both regimens of supplementation did not differently affect disease activity nor SLE serology.

Typing TREX1 gene in patients with systemic lupus erythematosus

An impaired expression of interferon-α regulated genes has been reported in patients with either systemic lupus erythematosus (SLE) or Aicardi-Goutières syndrome (AGS), a rare monogenic encephalopathy with onset in infancy. One of mutations causing AGS is located in the TREX1 gene on chromosome 3. Heterozygous mutations in TREX1 were reported in SLE patients. TREX1 is a DNA exonuclease with specificity for ssDNA. An impairment of its activity may result in the accumulation of nucleid acid. A recent study described a significant association between a haplotype including several common single nucleotide polymorphisms (SNPs) of TREX1 and neurological manifestations in European SLE patients. Fifty-one SLE patients were screened for TREX1 gene, and the corresponding data were collected from clinical charts. A novel heterozygous variant (p.Asp130Asn) was identified in one patient and in none of 150 controls. A missense variation was located in one of the three active sites of the gene and was classified as probably damaging. Variations of SNP rs11797 were detected in 33 SLE patients and a variation of rs3135944 in one. A significantly higher rate of the minor allele (T nucleotide) of SNP rs11797 was found in SLE patients with neuropsychiatric manifestations [12/16 (75%) vs 28/86 (32.5%) O=0.002, odds ratio=6.42 95% confidence interval (1.7-26.2)]. Only 1 out of 8 patients (12.5%) with neuropsychiatric SLE carried the wild-type form in homozygosity. Although we analyzed a small number of patients, we found a novel variation of TREX1, which may be pathogenic. The polymorphism of rs11797 was more frequent in SLE patients with neurological manifestations.