A population-specific diabetogenic haplotype HLA-A2,Cw1,B56,DR4,DQ8 is associated with high birthweight in Finnish diabetic families.

Children with type 1 diabetes (T1D) susceptibility HLA genotypes are shown to have an increased birthweight. We investigated to what extent T1D-predisposing HLA haplotypes were associated with increased birthweight. A total of 1255 Finnish children comprising those with T1D and their non-diabetic siblings were investigated. A total of 342 children and their non-diabetic parents were HLA genotyped. Birthweight data were obtained from the national Medical Birth Registry. The population-specific diabetogenic haplotype HLA-A2,Cw1,B56,DR4,DQ8 was associated with high birthweight (P=0.0280) in families with a diabetic offspring. Other T1D-predisposing HLA haplotypes showed nonsignificant tendency with high birthweight. More infants with a birthweight >or=4000 g were born in families with a T1D offspring than in the general Finnish population (P=0.0139). The previously observed direct association between birthweight and T1D risk may be mediated through the modulating effects that T1D susceptibility HLA genes have on weight. High birthweight and subsequent weight gain may accelerate the ongoing pancreatic autoimmune process in genetically susceptible individuals. The high proportion of infants having a birthweight >or=4000 g in families with a diabetic offspring raises a concern of potential adverse health outcomes that high birthweight can have.

Clinical and laboratory characteristics of Finnish lupus erythematosus patients with cutaneous manifestations.

Our objective was to characterize clinical features, laboratory findings, concomitant autoimmune diseases, and smoking habits of lupus erythematosus subgroups in genetically homogeneous patients from two Dermatology Departments of Finnish University hospitals. One hundred and seventy eight discoid lupus erythematosus, 55 subacute cutaneous lupus erythematosus, and 77 systemic lupus erythematosus patients were enrolled using patients' charts from institutional database (1995-2006) and during routine control visits. Clustering analysis was performed to reveal natural groupings. Smoking at the onset of disease was significantly more common in all subgroups (57% for discoid lupus erythematosus, 35% for subacute cutaneous lupus erythematosus, and 34% for systemic lupus erythematosus) compared with the age/gender-matched prevalence in the Finnish population, suggesting smoking to be a trigger factor for cutaneous lupus. Leukopenia (38%) and lymphopenia (52%) were observed more often in patients with systemic lupus erythematosus than reported previously. Photosensitivity characterized all groups, especially patients with subacute cutaneous lupus erythematosus (87%). Of the autoimmune diseases, Sjögren's syndrome was the most common (22% of patients with systemic lupus erythematosus), followed by autoimmune thyroid disease (13% of patients with subacute cutaneous lupus erythematosus). The clustering analysis showed environmental factors (smoking) to be more involved in disease development in discoid lupus erythematosus, whereas immunological factors were more significant in initiating systemic lupus erythematosus. The high prevalence of autoimmune thyroid disease, together with photosensitivity, and the clustering profiles suggest that lupus erythematosus subtypes, especially discoid lupus erythematosus, are heterogeneic in their pathomechanisms.

Matrix metalloproteinases as mediators of tissue injury in different forms of cutaneous lupus erythematosus.

BACKGROUND: Matrix metalloproteinases (MMPs) contribute to tissue destruction, regeneration, inflammation and apoptosis and several of them are upregulated by ultraviolet (UV) radiation in skin. Although some MMPs associate with organ manifestations of systemic lupus erythematosus (SLE), their role in cutaneous lupus erythematosus (LE) is elusive. OBJECTIVES: Our aim was to evaluate the expression of MMPs in SLE, subacute cutaneous LE (SCLE) and discoid LE (DLE) skin lesions and their relation to apoptosis and epidermal changes. METHODS: Lesional skin biopsies from 20 patients with SLE, 20 with DLE and 17 with SCLE, and from UVA/UVB-photoprovoked skin of healthy volunteers were immunostained using antibodies to multiple MMPs and tissue inhibitors of metalloproteinases (TIMPs). The TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling) method was used for detection of apoptosis. RESULTS: MMP-3, -10, -19 and -26 were abundantly expressed by keratinocytes in SLE, DLE and SCLE skin samples. MMP-7 was detected in keratinocytes in regions of oedema and vacuolization especially in SLE and SCLE, while MMP-14 was only occasionally observed in keratinocytes. Photoprovocation did not induce MMP-10 or -26 expression in skin of healthy volunteers. Epithelial TIMP-1 expression was low while occasional positive fibroblasts were seen in the dermis. TIMP-3 was abundantly expressed in the epidermis, endothelial cells and macrophages. CONCLUSIONS: Different subtypes of cutaneous LE are fairly similar in their MMP expression profile. MMP-3 and -10 mediate both epidermal changes and dermal tissue remodelling but are not present in lymphocytes. Low expression of TIMP-1 suggests that lupus skin is characterized by proteolytic events, and targeted action using selective MMP inhibitors may reduce lupus-induced damage in inflamed tissues.