History of atopy or autoimmunity increases risk of alopecia areata.

BACKGROUND: The association between a history of atopy or autoimmune diseases and risk of alopecia areata (AA) is not well established. OBJECTIVE: The purpose of this study was to use the National AA Registry database to further investigate the association between history of atopy or autoimmune diseases and risk of AA. METHODS: A total of 2613 self-registered sporadic cases (n = 2055) and controls (n = 558) were included in this analysis. RESULTS: Possessing a history of any atopic (odds ratio = 2.00; 95% confidence interval 1.50-2.54) or autoimmune (odds ratio = 1.73; 95% confidence interval 1.10-2.72) disease was associated with an increased risk of AA. There was no trend for possessing a history of more than one atopic or autoimmune disease and increasing risk of AA. LIMITATIONS: Recall, reporting, and recruiting bias are potential sources of limitations in this analysis. CONCLUSION: This analysis revealed that a history of atopy and autoimmune disease was associated with an increased risk of AA and that the results were consistent for both the severe subtype of AA (ie, alopecia totalis and alopecia universalis) and the localized subtype (ie, AA persistent).

Familial alopecia areata and chronic thrombocytopenia.

Alopecia areata (AA) has a strong hereditary component and is associated with a number of other autoimmune diseases. There is no established relationship between AA and any of the congenital thrombocytopenias. We report a family in which multiple members are affected with AA and with a hereditary thrombocytopenia, most consistent with pseudo-von Willebrand disease. This raises the possibility of a genetic association between AA and one or more of the inherited thrombocytopenias, possibly both related to mutations in genes on chromosome 17.

Multiple cutaneous neuromas and macular amyloidosis associated with medullary thyroid carcinoma.

Multiple cutaneous neuromas are rarely seen in dermatology practice. We report a case of multiple cutaneous neuromas, macular amyloidosis (MA), and medullary thyroid carcinoma (MTC) and discuss the interrelationship of the associated conditions. Multiple endocrine neoplasia 2 (MEN 2) is a hereditary syndrome that comprises MEN 2A, MEN 2B, and familial MTC. Germline mutations in the RET proto-oncogene is the underlying cause of the syndrome. MEN 2A and MEN 2B show some common endocrine manifestations including MTC and pheochromocytoma. There are reports of families with MA and MEN 2A. Multiple mucosal neuromas occur in 100% of patients with MEN 2B syndrome. Cutaneous neuromas are infrequently reported in MEN 2B syndrome. Our patient was a heterozygote carrier of GAG-->GAC mutation (Glu 768 Asp) in exon 13, codon 768 of the RET proto-oncogene. We speculate that our patient may represent an unusual presentation of MEN 2B or an overlap of MEN 2A and MEN 2B syndromes or a sporadic MTC case with unusual associations.

Major histocompatibility complex class I chain-related gene A polymorphisms and extended haplotypes are associated with familial alopecia areata.

Alopecia areata (AA) is characterized by hair loss in patches and may progress to total loss of scalp hair, or total loss of scalp and body hair. The major histocompatibility complex (HLA) is associated with susceptibility to AA, as well as other autoimmune diseases. In addition to HLA molecules, non-HLA molecules including the major histocompatibility complex class I chain-related gene A (MICA), a stress-inducible antigen, are also associated with several autoimmune diseases. To investigate associations between AA and the HLA loci, two genes and eight microsatellite markers spanning the HLA region were genotyped. MICA(*)6 was significantly associated with all phenotypes of AA (P=0.0083), whereas MICA(*)5.1 was significantly associated with patchy AA (P=0.029). Extended haplotype analysis shows the significant associations of haplotypes HLA-DQ1-DR6-MICA(*)5.1 (P=0.004) and HLA-DQB1*0201-DR3-MICA(*)5.1 (P=0.009) with AA. These results suggest that MICA is both a potential candidate gene and part of an extended HLA haplotype that may contribute to susceptibility to and severity of AA.

Interleukin-1 receptor antagonist allele 2 and familial alopecia areata.

Alopecia areata affects 1%-2% of the population and is hypothesized to be an autoimmune, organ specific T-cell mediated reaction directed against the human hair follicle. It is characterized by loss of hair in patches (alopecia areata) with progression in some individuals to total loss of scalp hair (alopecia totalis) or to loss of all scalp and body hair (alopecia universalis). The interleukin-1 receptor antagonist (IL-1RN) gene was found to be associated with more severe clinical outcome in several chronic inflammatory diseases, including alopecia areata. The IL-1RN*2 allele was found to be associated with alopecia areata severity in a British case-control study. In this paper, we analyzed alopecia areata probands in a family-based sample (n = 131 parent-offspring trios) to study the association between alleles of the IL-1RN and various phenotypes of alopecia areata. In considering all patients with any form of alopecia areata, no association was found with IL-1RN. IL-1RN*2 allele was not associated with alopecia totalis and alopecia universalis. A borderline association was observed between IL-1RN and patchy alopecia areata but it was not statistically significant (p =0.06). We also observed an association between IL1-RN*1 allele and patchy alopecia areata (p =0.045).