Low versus high-dose iloprost therapy over 21 days in patients with secondary Raynaud's phenomenon and systemic sclerosis: a randomized, open, single-center study

OBJECTIVE

We compared the efficacy of different dosages of longterm iloprost treatment on Raynaud's phenomenon (RP), ulcer healing, skin thickening, and progression of internal organ sclerosis in patients with systemic sclerosis (SSc).

METHODS

Fifty patients with SSc were randomized 1:1 for the maximally tolerated dose up to 2 ng/kg body weight per minute or low-dose (0.5 ng/kg bw per min) intravenous iloprost administration, applied for 6 hours daily over 21 days. Effects on RP, ulcer healing, skin thickness, esophageal function, and lung involvement assessed by forced vital capacity (FVC) and DLCO were measured, as well as side effects.

RESULTS

Both regimens yielded 70% reduction of digital ulcers, 40% reduction in frequency of RP, and 30% reduction in duration of RP. One year after therapy, the modified Rodnan skin score appeared to be unchanged. FVC and DLCO-SB were stable in 87% and 74% of the patients, respectively. The effect of iloprost on skin thickness and lung function was sustained in a subgroup of patients receiving several courses of iloprost. As assessed by a patient questionnaire, 12% of all patients did not respond to iloprost therapy, but 78% experienced a longlasting effect. Mild side effects were common in both groups, but did not lead to discontinuation of therapy.

CONCLUSION

Low-dose iloprost was shown to be equally effective as high-dose iloprost in longterm treatment and was very effective in therapy of digital ulcers. Registered in www.ClinicalTrials.gov (registration no. NCT00622687).

Strong acceleration of murine lupus by injection of the SmD1(83-119) peptide

OBJECTIVE

The mechanisms of IgG anti-double-stranded DNA (anti-dsDNA) antibody induction are incompletely understood. We recently demonstrated a high prevalence of autoantibodies to the C-terminus of SmD1 in patients with systemic lupus erythematosus (SLE) that was closely associated with anti-dsDNA reactivity. The aim of the present study was to analyze the influence of the SmD1 C-terminus on the generation of pathogenic anti-dsDNA antibodies in a murine model of SLE.

METHODS

Female lupus-prone prenephritic (NZB x NZW)F1 mice (NZB/NZW mice) as well as female control BALB/c, NZW, and (BALB/c x NZW)F, mice (CWF1 mice) were subcutaneously injected with keyhole limpet hemocyanin (KLH)-coupled SmD1(83-119). Controls received injections of recombinant SmD1 (rSmD1), KLH-rSmD1, KLH-coupled randomized peptide of SmD1(83-119), ovalbumin, or saline. Animals were monitored for survival and proteinuria and for levels of plasma creatinine, urea, and autoantibodies. In addition, histologic examinations were performed and T cell responses against SmD1(83-119) peptide and rSmD1 protein were determined in SmD1(83-119)-treated and -untreated NZB/NZW mice.

RESULTS

Immunization with KLH-SmD1(83-119), but not with control peptide, significantly accelerated the natural course of lupus in NZB/NZW mice, with premature renal failure and increased development of anti-dsDNA antibodies. Control strains of mice remained healthy, with no relevant anti-SmD1(83-119) antibodies detectable even after immunization. In contrast to findings in control mice, a T cell response against SmD1(83-119) was already present in unmanipulated NZB/NZW mice, and this response was further amplified after immunization.

CONCLUSION

The SmD1(83-119) peptide can influence the pathogenic anti-dsDNA response in the NZB/NZW murine lupus model. The data suggest that an SmD1(83-119)-specific T cell response is critical. Therefore, modulation of these autoantigen-specific T cells by tolerance induction may provide a therapeutic approach to specific immunosuppression in lupus.