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Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States
Arthritis & Rheumatology (Impact Factor: 7.76). 08/2007; 56(8):2719-28. DOI: 10.1002/art.22751
Source: PubMed


To evaluate whether seasonal early environmental exposures might influence later development of autoimmune disease, by assessing distributions of birth dates in groups of patients with idiopathic inflammatory myopathies (IIMs).
We assessed birth patterns in groups of patients with juvenile-onset IIM (n = 307) and controls (n = 3,942) who were born between 1970 and 1999, and in groups of patients with adult-onset IIM (n = 668) and controls (n = 6,991) who were born between 1903 and 1982. Birth dates were analyzed as circular data. Seasonal clustering was assessed by the Rayleigh test, and differences between groups by a rank-based uniform scores test.
The overall birth distributions among patients with juvenile IIM and among patients with adult IIM did not differ significantly from those among juvenile and adult controls, respectively. Some subgroups of patients with juvenile IIM had seasonal birth distributions. Hispanic patients with juvenile-onset IIM had a seasonal birth pattern (mean birth date October 16) significantly different from that of Hispanic controls (P = 0.002), who had a uniform birth distribution, and from that of non-Hispanic patients with juvenile-onset IIM (P < 0.001), who had a mean birth date of May 2. Juvenile dermatomyositis patients with p155 autoantibody had a birth distribution that differed significantly from that of p155 antibody-negative juvenile dermatomyositis patients (P = 0.003). Juvenile IIM patients with the HLA risk factor allele DRB1*0301 had a birth distribution significantly different from those without the allele (P = 0.021). Similar results were observed for juvenile and adult IIM patients with the linked allele DQA1*0501, versus juvenile and adult IIM patients without DQA1*0501, respectively. No significant patterns in birth season were found in other subgroups.
Birth distributions appear to have stronger seasonality in juvenile than in adult IIM subgroups, suggesting greater influence of perinatal exposures on childhood-onset illness. Seasonal early-life exposures may influence the onset of some autoimmune diseases later in life.

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Available from: Lisa G. Rider Md, Aug 20, 2014
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    • "An association between anti-Mi2-positive DM and surface ultraviolet radiation exposure has also been demonstrated [76]. In JDM different birth patterns have been observed for patients with and without anti-TIF1γ antibodies, suggesting perinatal or early life exposures may play a role [77]. "
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    ABSTRACT: Adult and juvenile dermatomyositis share the hallmark features of pathognomic skin rash and muscle inflammation, but are heterogeneous disorders with a range of additional disease features and complications. The frequency of important clinical features such as calcinosis, interstitial lung disease and malignancy varies markedly between adult and juvenile disease. These differences may reflect different disease triggers between children and adults, but whilst various viral and other environmental triggers have been implicated, results are so far conflicting. Myositis-specific autoantibodies can be detected in both adults and children with idiopathic inflammatory myopathies. They are associated with specific disease phenotypes and complications, and divide patients into clinically homogenous subgroups. Interestingly, whilst the same autoantibodies are found in both adults and children, the disease features remain different within autoantibody subgroups, particularly with regard to life-threatening disease associations, such as malignancy and rapidly progressive interstitial lung disease. Our understanding of the mechanisms that underlie these differences is limited by a lack of studies directly comparing adults and children. Dermatomyositis is an autoimmune disease, which is believed to develop as a result of an environmental trigger in a genetically predisposed individual. Age-specific host immune responses and muscle physiology may be additional complicating factors that have significant impact on disease presentation. Further study into this area may produce new insights into disease pathogenesis.
    Arthritis research & therapy 04/2013; 15(2):211. DOI:10.1186/ar4198 · 3.75 Impact Factor
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    ABSTRACT: The clinical profile of 7 children and their follow-up is described. There was female preponderance with mate to female ratio of 1:6. The median age of onset was 6 years. All the patients had skin rash, muscle weakness and abnormal enzyme profile. Muscle biopsy was performed in 6 and was abnormal in all of them. The electromyogram (EMG) was performed in 6 and was found abnormal in five. All the children responded well to corticosteroids. Two children received intravenous dexamethasone bolus and showed good response.
    The Indian Journal of Pediatrics 04/1992; 63(3):375-9. DOI:10.1007/BF02751533 · 0.87 Impact Factor
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