Promoter region polymorphism of macrophage migration inhibitory factor is strong risk factor for young onset of extensive alopecia areata

Alopecia Areata: A Review of the Genetic Variants and Immunodeficiency Disorders Associated with Alopecia Areata

Alopecia areata (AA) is an autoimmune form of non-scarring hair loss that occurs on a spectrum from patchy loss of hair on the scalp, to complete hair loss. Histology features can vary, but increased abundance of telogen hair and miniaturized hair follicles are classic hallmarks [Clin Cosmet Investig Dermatol. 2015;8:397-403]. Additionally, lymphocytic infiltration of the hair bulb is a commonly observed histology feature of AA which underscores how the disease is an autoimmune-mediated one that results from immune-mediated attack of the hair follicle. In a healthy individual, the hair follicle is one of the body's immune-privileged sites, but the breakdown of this immune privilege is thought to be an important driver in AA disease development. Diagnosis of AA is usually based on phenotypic manifestations in conjunction with biopsies which can help conclude whether the hair loss is autoimmune based. However, varied manifestation of disease both clinically and histologically makes diagnosis criteria more ambiguous and early identification of disease harder to achieve. A better understanding of genes that are associated with increased AA risk may help elucidate potential gene targets for future therapeutics.

The current state of knowledge of the immune ecosystem in alopecia areata

Alopecia areata (AA) is an autoimmune disease that affects approximately 2% of the general population. Patients with AA most commonly present with one or more patches of hair loss on the scalp in defined circular areas. A fraction of patients progress to more severe forms of the disease, in some cases with involvement of all body surfaces. The healthy anagen stage hair follicle is considered an immune privileged site, described as an environment that suppresses inflammatory immune responses. However, in AA, this immune privileged state collapses and marks the hair follicle as a target for the immune system, resulting in peri- and intrafollicular infiltration by lymphocytes. The complexity of the inflammatory ecosystem of the immune response to the hair follicle, and the relationships between the cellular and soluble participants, in AA remains incompletely understood. Many studies have demonstrated the presence of various immune cells around diseased hair follicles; however, often little is known about their respective contributions to AA pathogenesis. Furthering our understanding of the mechanisms of disease in AA is essential for the novel identification of targeted therapeutics that are efficacious and have few unintended effects.

Human papillomavirus symptomatic infection associated with increased risk of new-onset alopecia areata: A nationwide population-based cohort study

BACKGROUND

We investigated the correlation between a history of human papillomavirus (HPV) infection and alopecia areata risk.

METHODS

The study cohort comprised 30,001 patients with newly diagnosed HPV infection between 2000 and 2012; and with use of computer-generated randomly numbers, patients not had HPV infection were randomly selected as the comparison cohort. HPV infection cohort were matched to comparison individuals at a 1:1 ratio by age, gender and index year. All study individuals were followed up until they developed alopecia areata, withdraw from the insurance program, lost to follow-up, or until the end of 2013. Cox proportional hazards regression analysis was used to analyze the risk of alopecia areata with hazard ratios (HRs) and 95% confidence intervals (CIs) between the HPV and control cohort.

RESULTS

The adjusted hazard ratio (aHR) of alopecia areata for HPV patients relative to controls was 2.55 (95% C.I. = 1.88-3.47) after adjusting sex, age and comorbidities. Subgroup analysis indicated that patients with HPV infections had a significantly greater risk of alopecia areata for both genders, all age subgroups, and those with mental disorder diseases.

CONCLUSIONS

A history of HPV infection is associated with the development of subsequent alopecia areata in Taiwanese subjects.

Pediatric Alopecia Areata

BACKGROUND

Alopecia areata (AA) is a non-scarring hair loss disorder of autoimmune etiology.

OBJECTIVE

To familiarize physicians with the clinical presentation, diagnosis, evaluation, and management of pediatric alopecia areata.

METHODS

The search term "Alopecia areata" was entered into a Pubmed search. A narrow scope was applied to the categories of "epidemiology", "clinical diagnosis", "investigations", "comorbidities", and "treatment". Meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews were included. Only papers published in the English language were included. A descriptive, narrative synthesis was provided of the retrieved articles.

RESULTS

AA is an autoimmune disease of unknown etiology. It is the third most common dermatologic presentation in children with a lifetime risk of 1-2%. Diagnosing AA can be made on the basis of the history and clinical findings. Patients will often present with patchy, non-scarring hair loss, generally affecting the scalp. History may reveal a personal or family medical history of autoimmune or atopic disease or a recent stressful event. Tricoscopic examination will classically show "exclamation point hairs" and "yellow dots". Nonspecific nail changes may be present. Other clinical variants include alopecia totalis, alopecia universalis, ophiasis, sisaipho, and Canitis subita. There are multiple treatment options for AA, including conservative treatment, and topical, oral, and injectable medications.

CONCLUSION

AA is an autoimmune disease with a heterogeneous presentation and unpredictable clinical course. Although there is no cure for AA, there are many current treatment options available to help manage this disfiguring disease.

Bidirectional association between alopecia areata and major depressive disorder among probands and unaffected siblings: A nationwide population-based study

BACKGROUND

Alopecia areata (AA) has long been associated with major depressive disorder (MDD). However, most evidence to date has derived from cross-sectional or case-control studies.

OBJECTIVE

To investigate the bidirectional association between AA and MDD among probands and unaffected siblings.

METHODS

Study participants were recruited from the National Health Insurance Research Database in Taiwan. We included 2123 probands with AA, 2298 unaffected siblings, and 9192 matched controls to assess the risk of MDD. We included 16,543 probands with MDD, 17,352 unaffected siblings, and 69,408 matched controls to assess the risk of AA. The Breslow-Cox model was used to calculate the adjusted relative risk.

RESULTS

Compared with controls, AA probands and unaffected siblings had adjusted relative risks of 8.22 (95% confidence interval [CI], 6.41-10.54) and 2.55 (95% CI, 1.91-3.40), respectively, for MDD. MDD probands and unaffected siblings had adjusted relative risks for AA of 1.66 (95% CI, 1.24-2.22) and 1.64 (95% CI, 1.27-2.12), respectively.

LIMITATION

The National Health Insurance Research Database lacked information on disease severity, body mass index, smoking habit, alcohol consumption, and stressful life events.

CONCLUSION

Our study demonstrated a bidirectional association between AA and MDD among probands and unaffected siblings, thus suggesting shared familial mechanisms underlying AA and MDD.

Genotyping Two Promoter Polymorphisms in the MIF Gene: A -794 CATT5-8 Microsatellite Repeat and a -173 G/C SNP

Macrophage migration inhibitory factor (MIF) is an upstream proinflammatory cytokine encoded by a functionally polymorphic locus. The promoter region of the human MIF gene contains two polymorphisms. A variable nucleotide tandem repeat at position -794 comprises five to eight CATT repeats (referred to henceforth by numbers from 5 to 8, rs5844572). Gene reporter assays show a proportional increase in transcription with CATT repeat number; the 5-repeat allele leads to low expression, and the 6-, 7-, and 8-repeat alleles lead to correspondingly higher expression of MIF. A second MIF promoter polymorphism comprises a G-to-C single nucleotide polymorphism (SNP) at position -173 (rs755622), which is in strong linkage disequilibrium with -794 7-CATT and is associated with arthritis clinical severity and higher serum and synovial fluid MIF levels. This allele also has been reported to confer improved survival in patients with outpatient pneumonia. In this chapter, we will introduce the methods of genotyping CATT_5-8 repeats and the MIF -173 G/C from human samples.

Candidate Gene Analysis Of Alopecia Areata In Jordanian Population Of Arab Descent: A Case-Control Study

Background

Alopecia areata (AA) is a non-cicatricial patchy hair loss on the scalp, face or other parts of the body. AA was found to be responsive to immunosuppressive therapies, a finding that supports an autoimmune basis for the disease. Several genetic studies have shown the significance of immunological factors as key genetic components in AA.

Objective

In this study, we aimed to investigate the genetic association of 7 single-nucleotide polymorphisms (SNPs) within five candidate genes including TAP1, CXCL1, CXCL2, HSPA1B, and TNFα with AA susceptibility in the Jordanian Arab population.

Methods

A case–control genetic association study conducted in 152 patients and 150 healthy individuals was performed using the sequenom MassARRAY system (iPLEX GOLD) to genotype the selected SNPs.

Results

rs1800629 SNP of the TNFα gene was significantly associated with AA in the heterozygous and rare homozygous genotypes (P=0.022 and P=0.0079, respectively) with no linkage of the TAP1, CXCL1, CXCL2 and HSPA1B variants.

Conclusion

This is the first study of its kind among the Jordanian population providing evidence of genetic association of the TNFα with AA susceptibility. Further genetic studies on Arab descent including other variants are required to clarify and strengthen the association of these genes with susceptibility to develop AA.

Alopecia areata: a review of disease pathogenesis

BACKGROUND

Alopecia areata is a disorder that results in nonscarring hair loss. The psychological impact can be significant, leading to feelings of depression and social isolation. Objectives In this article, we seek to review the pathophysiological mechanisms proposed in recent years in a narrative fashion.

METHODS

We searched MEDLINE and Scopus for articles related to alopecia areata, with a particular emphasis on its pathogenesis.

RESULTS

The main theory of alopecia areata pathogenesis is that it is an autoimmune phenomenon resulting from a disruption in hair follicle immune privilege. What causes this breakdown is an issue of debate. Some believe that a stressed hair follicle environment triggers antigen presentation, while others blame a dysregulation in the central immune system entangling the follicles. Evidence for the latter theory is provided by animal studies, as well investigations around the AIRE gene. Different immune-cell lines including plasmacytoid dendritic cells, natural killer cells and T cells, along with key molecules such as interferon-γ, interleukin-15, MICA and NKG2D, have been identified as contributing to the autoimmune process.

CONCLUSIONS

Alopecia areata remains incurable, although it has been studied for years. Available treatment options at best are beneficial for milder cases, and the rate of relapse is high. Understanding the exact mechanisms of hair loss in alopecia areata is therefore of utmost importance to help identify potential therapeutic targets.

A Macrophage Migration Inhibitory Factor Polymorphism Is Associated with Autoimmune Hepatitis Severity in US and Japanese Patients

BACKGROUND

The pathogenesis of autoimmune hepatitis (AIH) is incompletely understood. Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine implicated in the pathophysiology of multiple autoimmune diseases. We recently reported that MIF expression was increased in a US AIH cohort. MIF expression in non-Western AIH patients is unknown. A MIF-173 GC single nucleotide polymorphism in the MIF promoter (rs755622) is clinically associated with steroid resistance in several inflammatory disorders but has not been evaluated in AIH.

AIM

To compare MIF polymorphisms and their relationship to clinical parameters in AIH patients from the USA and Japan.

METHODS

DNA and matched sera from AIH patients and healthy controls from Japan (N = 52) were compared to the US group. Serum concentrations of MIF and its circulating receptor CD74 were measured by ELISA. MIF-173 GC (rs755622) and MIF-794 CATT_5-8 (rs5844572) polymorphisms were analyzed by standard methods. MIF genotypes were correlated with serum ALT and steroid requirements.

RESULTS

Serum MIF was increased in Japanese AIH patients versus local controls, in agreement with the US AIH patients. Within both AIH groups, ALT was higher in CC/GC versus GG patients. Further, the steroid requirement was higher in AIH patients with GC/CC genotypes from both groups. In the Japanese patient group, the GC/CC genotype also was associated with acute symptomatic presentation.

CONCLUSIONS

The MIF-173 CC/GC genotypes may be associated with both higher ALT and maintenance steroid requirements in AIH patients from the USA and Japan. This polymorphism could be a marker of disease severity in AIH patients.

Association of macrophage migration inhibitory factor promoter polymorphism -173G/C with susceptibility to childhood asthma

Introduction

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that plays an important role in the pathogenesis of asthma. Polymorphisms associated with inflammatory diseases exist in the promoter region of MIF, which alter its expression. We aimed to study the association of MIF promoter polymorphism –173G/C with childhood asthma.

Material and methods

In this case-control study, we recruited 60 pediatric patients with bronchial asthma and 90 age- and sex-matched healthy controls. MIF-173G/C was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

Results

Genotype distribution between cases and healthy controls was statistically evaluated. Our results revealed that the frequency of the MIF-173C allele was significantly higher in children with asthma than in the control group (p = 0.002, odds ratio [OR] = 3.61, 95% confidence interval [CI] = 1.63-7.97). The frequency of the MIF-173CC genotype was higher in the asthmatic children than in the controls (p = 0.028, OR = 6.24, 95% CI = 1.24-31.29). Comparing carriage of the MIF-173C allele in pediatric patients with asthma with that observed in healthy controls (GC + CC vs. GG) revealed a positive association with the disease (p = 0.019, OR = 3.12, 95% CI = 1.22-7.99).

Conclusions

These results suggest that MIF-173G/C polymorphism confers an increased risk of susceptibility to the development of childhood asthma in an Egyptian population.

Association of Macrophage Migration Inhibitory Factor Polymorphisms with Total Plasma IgE Levels in Patients with Atopic Dermatitis in Korea

The macrophage migration inhibitory factor (MIF) gene is located on human chromosome 22q11.2 and is linked to atopic phenotypes. Plasma MIF and log [total IgE] levels are significantly elevated in atopic dermatitis (AD) patients. The aim of this study was to evaluate the relationship between two MIF polymorphisms, −173 G to C and −794 CATT_5–8, and total plasma IgE levels in AD patients in Korea. We performed PCR-RFLP analysis in 178 AD patients and 80 control subjects to determine whether MIF SNPs are associated with susceptibility to AD. Plasma total IgE and MIF levels were determined, and then logistic regression analyses were performed to determine the associations between a SNP or haplotype and plasma total IgE or MIF levels. The −173 G/C polymorphism, located in the MIF promoter, was significantly associated with AD; the odds ratios (ORs) for the CC homozygotes and GC heterozygotes were 9.3 and 2.5, respectively. The MIF C/5-CATT and the MIF C/7-CATT haplotypes were significantly associated with AD; the ORs for the MIF C/5-CATT and MIF C/7-CATT haplotypes were 9.7 and 4.5, respectively. Log [total IgE] levels were highly associated with the MIF −794 7-CATT polymorphism. Notably, the MIF C/7-CATT haplotype was associated with a decrease in plasma log [total IgE] levels in a gene dose-dependent manner. Although log [MIF] levels were not associated with the MIF polymorphisms, the frequencies of the MIF C/5-CATT haplotype-containing genotypes decreased in order of MIF levels. Our results demonstrate that MIF promoter polymorphisms in the −173 C allele and the MIF C/5-CATT and C/7-CATT haplotypes were significantly associated with an increased risk for AD. In particular, the −794 7-CATT locus and the MIF C/7-CATT haplotype were significantly associated with decreased total IgE levels in the plasma, suggesting that these polymorphisms might be a marker for intrinsic AD rather than extrinsic AD that shows high total IgE levels and presence of allergen-specific IgE.

Serum level of macrophage migration inhibitory factor (MIF) in Egyptians with alopecia areata and its relation to the clinical severity of the disease

BACKGROUND

Alopecia areata (AA) is a common dermatological problem that manifests as sudden loss of hair without any inflammation or scarring. Various cytokines are implicated in the pathogenesis of this disease. Macrophage migration inhibitory factor (MIF) is located at an upstream position in the events leading to the possible dysregulated immuno-inflammatory responses, and the high level of this cytokine in AA may suggest a role of MIF in the pathogenesis of AA.

METHODS

This case-control study was carried out on 31 AA patients with different grades of severity and 15 apparently healthy subjects. Serum MIF level was measured by ELISA, and was correlated with the clinical severity of the disease using SALT (severity of alopecia tool) scoring system.

RESULTS

In this study, there was a significant elevation in serum MIF levels in AA patients in comparison with controls. There was also a positive correlation between MIF levels and clinical severity and disease duration.

CONCLUSION

MIF seems to have an essential role in the etiopathogenesis of AA. So, it is considered to be a promising target in the therapy of autoimmune diseases and as a future predictor of alopecia activity. Anti-MIF therapy might be added as one of the new biological treatments for AA.

What causes alopecia areata?

The pathobiology of alopecia areata (AA), one of the most frequent autoimmune diseases and a major unsolved clinical problem, has intrigued dermatologists, hair biologists and immunologists for decades. Simultaneously, both affected patients and the physicians who take care of them are increasingly frustrated that there is still no fully satisfactory treatment. Much of this frustration results from the fact that the pathobiology of AA remains unclear, and no single AA pathogenesis concept can claim to be universally accepted. In fact, some investigators still harbour doubts whether this even is an autoimmune disease, and the relative importance of CD8(+) T cells, CD4(+) T cells and NKGD2(+) NK or NKT cells and the exact role of genetic factors in AA pathogenesis remain bones of contention. Also, is AA one disease, a spectrum of distinct disease entities or only a response pattern of normal hair follicles to immunologically mediated damage? During the past decade, substantial progress has been made in basic AA-related research, in the development of new models for translationally relevant AA research and in the identification of new therapeutic agents and targets for future AA management. This calls for a re-evaluation and public debate of currently prevalent AA pathobiology concepts. The present Controversies feature takes on this challenge, hoping to attract more skin biologists, immunologists and professional autoimmunity experts to this biologically fascinating and clinically important model disease.

Tolerance induction by hair-specific keratins in murine alopecia areata

AA is a presumptive autoimmune disease, severely damaging the hair follicle. Hair- and nail-specific keratins are discussed as potential candidates, which we controlled in C3H/HeJ mice that develop AA spontaneously or after skin transplantation. From nine keratins, K71 and K31 peptides supported T cell activation when presented by DCs to syngeneic naive T cells, and young C3H/HeJ mice receiving s.c. injections of peptide-loaded DC developed AA. The frequency of K71- and K31-specific CD4(+) and CD8(+) T cells increased four- to fivefold by vaccination, which corresponds with the frequency seen in skin transplantation-induced AA mice. Also, accessory molecule expression, the cytokine profile with a dominance of IFN-γ-expressing T cells, the proliferative response against AA lysate or peptide-loaded DCs, as well as peptide-specific cytotoxic T cells were similar in keratin peptide- and skin transplantation-induced AA. Instead, vaccination with soluble K71 or K31 peptides significantly retarded AA induction and prevented progression. Soluble peptide vaccination did not provoke immunosuppression but induced long-lasting T cell anergy with unresponsiveness to DC-presented K71 and K31 peptides. Thus, keratins K71 and K31 contribute to AA induction, and peptide application in a nonimmunogenic form serves as an efficient therapeutic.

Macrophage migration inhibitory factor as an incriminating agent in dermatological disorders

Macrophage migration inhibitory factor (MIF) is a critical immunoregulatory pluripotent cytokine. It has been re-evaluated as a proinflammatory cytokine, pituitary hormone and glucocorticoid-induced immunoregulatory protein. MIF exists in human epidermis, especially in the basal layer and also is expressed constitutively by monocytes/macrophages, T cells, B cells, endocrine, and epithelial cells. In the field of dermatology, MIF is believed to be a detrimental factor in inflammatory dermatological diseases including atopic dermatitis (AD), psoriasis, vitiligo, pemphigus vulgaris, bullous pemphigoid (BP), alopecia areata (AA) as well as other conditions such as photoaging, and photocarcinigenesis. The objective of this review is to gather and summarize MIF related disorders in dermatology and present valuable information for readers and researchers.

Insulin resistance is increased in alopecia areata patients

Increased insulin resistance (IR) has been found in androgenetic alopecia in several studies. However, IR has not been investigated in alopecia areata (AA). We aimed to investigate IR in AA patients and the controls. Anthropometric and demographic data were obtained from 51 AA patients and 36 controls. We measured insulin, c-peptide and blood glucose and HOMA-IR. Demographic characteristics of the two groups were similar. AA group had higher insulin [12.5 ± 7.01 vs. 8.3 ± 3.9 µIU/mL, p = 0.001], c-peptide [2.7 ± 1.07 vs. 2. ± 0.6 ng/mL, p = 0.007] and HOMA-IR levels [2.8 ± 1.6 vs. 1.9 ± 0.9, p = .004] than the controls. Patient and control groups were also similar regarding lipid profiles. In this study, we found increased IR in AA patients for the first time in literature. Increased inflammatory cytokines and hypothalamic-pituitary-adrenal axis activation may be responsible for this finding. Further studies with larger sample sizes may give additional information for IR in AA.

Association between IL17A/IL17RA Gene Polymorphisms and Susceptibility to Alopecia Areata in the Korean Population

Background

Alopecia areata is marked by autoimmune assault on the hair follicle resulting in hair loss. T helper 17 cell subset has important roles in protecting the host against extracellular pathogens, however, also promotes inflammatory pathology in autoimmune disease, and it expresses both interleukin (IL)-17A and IL-17F, which can signal via the IL-17 receptor A.

Objective

To investigate the significance of IL17A and IL17RA gene polymorphisms in the susceptibility to alopecia areata.

Methods

We conducted case-control association study of 238 alopecia areata patients and 270 matched healthy controls. Allele frequency of total 2 single nucleotide polymorphims in the IL17A gene and 4 single nucleotide polymorphims in the IL17RA gene were studied. The statistical analyses were performed according to onset age, the presence of familyhistory, clinical subtypes, and presence of nail involvement or body hair involvement.

Results

One single nucleotide polymorphim (rs879577) of IL17RA gene showed significant difference between alopecia areata patients group and controls group (p= 0.0288). One single nucleotide polymorphim (rs4819554) of IL17RA gene showed significant difference between the early onset and late onset alopecia areata (p=0.0421).

Conclusion

IL17RA gene polymorphism might contribute to the increased susceptibility to alopecia areata in Korean population, and IL17RA gene polymorphism may be associated with onset age.

Effects of the Lexington LaserComb on hair regrowth in the C3H/HeJ mouse model of alopecia areata

Alopecia areata (AA) is a common autoimmune disease that presents with non-scarring alopecia. It is characterized by intra- or peri-follicular lymphocytic infiltrates composed of CD4+ and CD8+ T-cells on histology. To this day, few treatments are effective for AA. Here we present findings of using a low-level laser comb to alleviate the symptoms of AA in a C3H/HeJ mouse model for AA. Fourteen C3H/HeJ mice with induced AA were used in this study. Two were killed to confirm AA through histology. The remaining 12 mice were randomized into two groups; group I received HairMax LaserComb (wavelength: 655 nm, beam diameter <5 mm; divergence 57 mrad; nine lasers) for 20 s daily, three times per week for a total of 6 weeks; group II was treated similarly, except that the laser was turned off (sham-treated). After 6 weeks of LaserComb treatment, hair regrowth was observed in all the mice in group I (laser-treated) but none in group II (sham-treated). On histology, increased number of anagen hair follicles was observed in laser-treated mice. On the other hand, sham-treated mice demonstrated hair follicles in the telogen phase with no hair shaft. LaserComb seems to be an effective and convenient device for the treatment of AA in the C3H/HeJ mouse model. Human studies are required to determine the efficacy and safety of this device for AA therapy.

Cytokines and other mediators in alopecia areata

Alopecia areata, a disease of the hair follicles with multifactorial etiology and a strong component of autoimmune origin, has been extensively studied as far as the role of several cytokines is concerned. So far, IFN-gamma, interleukins, TNF-alpha, are cytokines that are well known to play a major role in the pathogenesis of the disease, while several studies have shown that many more pathways exist. Among them, MIG, IP-10, BAFF, HLA antigens, MIG, as well as stress hormones are implicated in disease onset and activity. Within the scope of this paper, the authors attempt to shed light upon the complexity of alopecia areata underlying mechanisms and indicate pathways that may suggest future treatments.

Susceptibility to JRA/JIA: complementing general autoimmune and arthritis traits

Juvenile rheumatoid arthritis (JRA), also known as juvenile idiopathic arthritis (JIA), includes the most common chronic autoimmune arthropathies of childhood. These two nomenclatures for classification include components representing the major subclasses of disease. The chromosomal regions and the genes involved in these complex genetic traits are being elucidated, with findings often specific for a particular disease subtype. With the advent of new SNP technologies, progress is being made at an ever-increasing pace. This review discusses the difficulties of deciphering the genetic components in complex disorders, while demonstrating the similarities that JRA shares with other autoimmune disorders. Particular emphasis has been placed on positive findings either for candidate genes that have been replicated independently in JRA/JIA, or findings in JRA for which consistent results have been reported in other forms of autoimmunity.

Lymphocytes, neuropeptides, and genes involved in alopecia areata

Many lessons in autoimmunity - particularly relating to the role of immune privilege and the interplay between genetics and neuroimmunology - can be learned from the study of alopecia areata, the most common cause of inflammation-induced hair loss. Alopecia areata is now understood to represent an organ-restricted, T cell-mediated autoimmune disease of hair follicles. Disease induction is associated with collapse of hair follicle immune privilege in both humans and in animal models. Here, the role of HLA associations, other immunogenetic factors, and neuroendocrine parameters in alopecia areata pathogenesis are reviewed. This instructive and clinically significant model disease deserves more widespread interest in the immunology community.

Promoter polymorphism in the macrophage migration inhibitory factor gene is associated with obesity

OBJECTIVE

To explore the association of promoter polymorphisms of macrophage migration inhibitory factor (MIF) gene with obesity.

SUBJECTS

In total, 213 nondiabetic Japanese subjects. They were divided into three groups according to World Health Organization definitions: lean (body mass index (BMI) <25 kg/m2), overweight (25 < or = BMI < 30 kg/m2) and obese (BMI> or = 30 kg/m2).

METHODS

We examined two polymorphic loci in the MIF gene in the subjects: a single-nucleotide polymorphism at position -173 (G/C) and a CATT-tetranucleotide repeat polymorphism at position -794, which both can affect promoter activity in different cells.

RESULTS

We detected four alleles: 5-, 6-, 7- and 8-CATT at position -794. Genotypes without the 5-CATT allele (X/X, X refers to 6-, 7- or 8-CATT alleles) were more common in obese subjects than in lean or overweight groups (P = 0.013). The X-CATT allele was more frequent in obese subjects than in lean or overweight subjects (P = 0.030). In contrast, -173G/C was not associated with obesity. Among the haplotypes of the two promoter polymorphisms, G/5-CATT ((-173G/C)/(-794[CATT](5-8))) was associated with a decreased risk of obesity (P = 0.025) and G/6-CATT with an increased risk of overweight (P=0.028).

CONCLUSION

Promoter polymorphism in the MIF gene is linked with obesity.