Israel Medical Association Journal

Background: The activated NLRP3 inflammasome is associated with the etiology of fibrotic diseases. The role of inflammasomes in SSc is still poorly understood.

Objectives: To determine the expression of NLRP3 (nucleotide-binding domain, leucine-rich-repeat-containing family, pyrin domain-containing 3) in the skin of patients with systemic sclerosis (SSc) and its relationship with pro-inflammatory cytokines and vascular mediators expression.

Methods: Skin biopsies were taken from 42 patients with either limited or diffuse SSc (21 lcSSc and 21 dcSSc), and from 13 healthy individuals. Using real-time polymerase chain reaction (PCR), the relative expression of caspase-1, IL-1β, IL-18, IL-33, TGF-β, ET-1, iNOS and eNOS genes, were measured. The location of NLRP3 and IL-1β were also determined by immunohistochemistry. Clinical characteristics were evaluated.

Results: The mean age of the patients was 49.3 ± 12.9 (lcSSc), 44.6 ±1 3.8 (dcSSc), and 45 ± 14.1 (healthy individuals). Compared to healthy individuals, the skin of both subtypes of SSc showed a significant increase (P < 0.05) in NLRP3, caspase-1, IL-1β, IL-18 and ET-1. Samples of lcSSc also showed a significant increase of eNOS (P < 0.029), iNOS (P < 0.04) and TGF-β (P < 0.05). Dermal fibrosis evaluated by modified Rodnan skin score (MRSS) had significant correlation with NLRP3, IL-1β, IL-18, and ET-1. Immunohistochemical analysis showed stronger staining of NLRP3 and IL-1β cytoplasmic expression in the keratinizing squamous epithelium of skin from SSc patients compared to controls.

Conclusions: This study identified NLRP3 over-expression in skin of patients with SSc. Skin thickness correlates positively with the NLRP3 inflammasome gene expression and with the vascular mediator and pro-fibrotic ET-1, suggesting that NLRP3 inflammasome plays a role in the pathophysiology of skin fibrosis in human SSc.

Background: Overlap syndrome is an entity that satisfies the criteria of at least two connective tissue diseases. These conditions include systemic sclerosis, dermatomyositis or polymyositis, Sjogren's syndrome, rheumatoid arthritis and systemic lupus erythematosus. A combined pathology has impact on the clinical features, diagnosis and treatment.

Objectives: To analyze the features of SSc[1] patients with overlap syndrome registered in the European (EUSTAR) database at our center and to review the literature focusing on clinical and diagnostic issues and new treatments.

Methods: We studied the medical records of 165 consecutive SSc patients and reviewed cases with scleroderma overlap syndrome. Using the key words “overlap syndrome," "systemic sclerosis," “connective tissue disease” and “biological agents” we conducted a PubMed search for the period 1977 to 2009.

Results: Forty patients satisfied the criteria for scleroderma overlap syndrome. The incidence of additional connective tissue diseases in the whole group and in the overlap syndrome group respectively was: dermatomyositis or polymyositis 11.5% and 47.5%, Sjogren's syndrome 10.3% and 42.5%, rheumatoid arthritis 3.6% and 15.4%, and systemic lupus erythematosus 1.2% and 5.0%. Coexistence of SSc and another CTD[2] aggravated the clinical course, especially lung, kidney, digestive, vascular and articular involvement. Non-rheumatic complications mimicked SSc complications. An additional rheumatic or non-rheumatic disease affected treatment choice.

Conclusions: The definition of scleroderma overlap syndrome is important, especially in patients who need high-dose corticosteroids for complications of a CTD. The use of novel biological therapies may be advocated in these patients to avoid the hazardous influences of high-dose steroids, especially renal crisis. In some overlap syndrome cases, biological agents serve both conditions; in others one of the conditions may limit their use. In the absence of formal clinical trials in these patients a cautious approach is preferred.

Klinefelter's syndrome, which occurs in males, is not a rare gonosomal aberration. The disorder is characterized by micro-orchidism.