The Association between Alopecia and Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

Alopecia areata: What's new in the epidemiology, comorbidities, and pathogenesis?

BACKGROUND

Alopecia areata (AA) is a common, acquired, and nonscarring type of hair loss that affects people of every generation and is intractable in severe and relapsing cases. Patients with AA, especially those with greater scalp involvement, have poor health-related quality-of-life scores.

PURPOSE

Following our previous review article in the April 2017 issue of the Journal of Dermatological Science, we aim to provide a pair of review articles on recent progress in multidisciplinary approaches to AA.

MAIN FINDINGS

We found more than 1800 publications on AA from July 2016 to December 2022.

CONCLUSIONS

In this review, we focused on the latest information on the epidemiology, comorbidities, and pathogenesis of AA.

Gut microbiome, metabolome and alopecia areata

Alopecia areata (AA) is a type of dermatological disease characterized by rapid and non-scarring hair loss of the scalp or body skin that may be related to genetic, immunological and physiological factors. It is now believed that AA is associated with oxidative stress, autoimmune disease, neuropsychological factors, pathogens, immune checkpoint inhibitors and microecological imbalance under the premise of host genetic susceptibility. In recent years, studies have revealed the significant role of the gut microbiome or metabolome in many aspects of human health. Diverse studies have revealed that the gut microbiome and metabolome have an important influence on skin conditions. This review highlights the relationship between AA and the gut microbiome or metabolome to provide novel directions for the prevention, clinical diagnosis and treatment of AA.

Inflammation and Digestive Cancer

Chronic inflammation is linked to carcinogenesis, particularly in the digestive organs, i.e., the stomach, colon, and liver. The mechanism of this effect has, however, only partly been focused on. In this review, we focus on different forms of chronic hepatitis, chronic inflammatory bowel disease, and chronic gastritis, conditions predisposing individuals to the development of malignancy. Chronic inflammation may cause malignancy because (1) the cause of the chronic inflammation is itself genotoxic, (2) substances released from the inflammatory cells may be genotoxic, (3) the cell death induced by the inflammation induces a compensatory increase in proliferation with an inherent risk of mutation, (4) changes in cell composition due to inflammation may modify function, resulting in hormonal disturbances affecting cellular proliferation. The present review focuses on chronic gastritis (Helicobacter pylori or autoimmune type) since all four mechanisms may be relevant to this condition. Genotoxicity due to the hepatitis B virus is an important factor in hepatocellular cancer and viral infection can similarly be central in the etiology and malignancy of inflammatory bowel diseases. Helicobacter pylori (H. pylori) is the dominating cause of chronic gastritis and has not been shown to be genotoxic, so its carcinogenic effect is most probably due to the induction of atrophic oxyntic gastritis leading to hypergastrinemia.

Overview of alopecia areata for managed care and payer stakeholders in the United States

Alopecia areata (AA) is an autoimmune disease with a complex pathophysiology resulting in nonscarring hair loss in genetically susceptible individuals. We aim to provide health care decision makers an overview of the pathophysiology of AA, its causes and diagnosis, disease burden, costs, comorbidities, and information on current and emerging treatment options to help inform payer benefit design and prior authorization decisions. Literature searches for AA were conducted using PubMed between 2016 and 2022 inclusive, using search terms covering the causes and diagnosis of AA, pathophysiology, comorbidities, disease management, costs, and impact on quality of life (QoL). AA is a polygenic autoimmune disease that significantly impacts QoL. Patients with AA face economic burden and an increased prevalence of psychiatric disease, as well as numerous systemic comorbidities. AA is predominantly treated using corticosteroids, systemic immunosuppressants, and topical immunotherapy. Currently, there are limited data to reliably inform effective treatment decisions, particularly for patients with extensive disease. However, several novel therapies that specifically target the immunopathology of AA have emerged, including Janus kinase (JAK) 1/2 inhibitors such as baricitinib and deuruxolitinib, and the JAK3/tyrosine kinase expressed in hepatocellular carcinoma (TEC) family kinase inhibitor ritlecitinib. To support disease management, a disease severity classification tool, the Alopecia Areata Severity Scale, was recently developed that evaluates patients with AA holistically (extent of hair loss and other factors). AA is an autoimmune disease often associated with comorbidities and poor QoL, which poses a significant economic burden for payers and patients. Better treatments are needed for patients, and JAK inhibitors, among other approaches, may address this tremendous unmet medical need. DISCLOSURES: Dr King reports seats on advisory boards for and/or is a consultant and/or clinical trial investigator for AbbVie, Aclaris Therapeutics Inc, AltruBio Inc, Almirall, Arena Pharmaceuticals, Bioniz Therapeutics, Bristol Meyers Squibb, Concert Pharmaceuticals Inc, Dermavant Sciences Inc, Eli Lilly and Company, Equillium, Incyte Corp, Janssen Pharmaceuticals, LEO Pharma, Otsuka/Visterra Inc, Pfizer, Regeneron, Sanofi Genzyme, TWi Biotechnology Inc, and Viela Bio; and speakers bureaus for AbbVie, Incyte, LEO Pharma, Pfizer, Regeneron, and Sanofi Genzyme. Pezalla is a paid consultant to Pfizer for market access and payer strategy concerns; Fung, Tran, Bourret, Takiya, Peeples-Lamirande, and Napatalung are employees of Pfizer and hold stock in Pfizer. This article was funded by Pfizer.

Successful treatment of concomitant alopecia universalis and Crohn’s disease with upadacitinib: A case report

Alopecia areata is a non-scarring, autoimmune hair loss disorder that is associated with inflammatory bowel disease. Alopecia areata and inflammatory bowel disease may have a common pathogenic mechanism that involves the Janus kinase/STAT pathway. In addition, there are previous case reports of patients who developed alopecia areata while on biologic therapies for inflammatory bowel disease. JAK1 inhibitors are currently undergoing investigation as potential therapies for Crohn’s disease. Upadacitinib, an oral JAK1 inhibitor, has demonstrated efficacy in treating Crohn’s disease during phase III clinical trials. In this case report, we present a 23-year-old man with Crohn’s disease who previously developed alopecia areata while on adalimumab. He had near-complete resolution of his alopecia universalis after 7 months of treatment with upadacitinib while on concurrent ustekinumab for Crohn’s disease, which he had been taking for 16 months prior to starting upadacitinib. Upadacitinib may be a beneficial therapy for treating concomitant alopecia areata and Crohn’s disease.

Immune-mediated diseases and subsequent risk of alopecia areata in a prospective study of US women

INTRODUCTION

Alopecia areata (AA) is the most common form of immune-mediated hair loss. Studies have begun to establish the most frequent comorbid diseases of AA; however, results have been inconsistent with few prospective studies.

METHODS

A total of 63,692 women in the Nurses' Health Study, 53-80 years, were prospectively followed from 2002 to 2014 to determine whether history of immune-mediated disease was associated with AA risk. Hazard ratios (HRs) and 95% confidence intervals (CIs) for AA in relation to immune-mediated conditions were computed using Cox proportional hazard models, adjusted for AA risk factors.

RESULTS

133 AA cases were identified during follow-up. Personal history of any immune-mediated disease was associated with increased AA risk (HR 1.72, 95% CI 1.24-2.37). History of systemic lupus erythematosus (HR 5.43, 95% CI 2.11-13.97), multiple sclerosis (HR 4.10, 95% CI 1.40-11.96), vitiligo (HR 3.13, 95% CI 1.08-9.10), psoriasis (HR 2.01, 95% CI 1.00-4.03), hypothyroidism (HR 1.88, 95% CI 1.30-2.71), and rheumatoid arthritis (HR 1.66, 95% CI 1.09-2.52) were associated with increased AA risk. History of inflammatory bowel disease or Graves' disease/hyperthyroidism was not significantly associated with AA risk.

CONCLUSIONS

In this prospective study, personal history of immune-mediated diseases either individually or overall was associated with increased AA risk.

How Our Microbiome Influences the Pathogenesis of Alopecia Areata

Alopecia areata is a multifactorial autoimmune-based disease with a complex pathogenesis. As in all autoimmune diseases, genetic predisposition is key. The collapse of the immune privilege of the hair follicle leading to scalp loss is a major pathogenic event in alopecia areata. The microbiota considered a bacterial ecosystem located in a specific area of the human body could somehow influence the pathogenesis of alopecia areata, as it occurs in other autoimmune diseases. Moreover, the Next Generation Sequencing of the 16S rRNA bacterial gene and the metagenomic methodology have provided an excellent characterization of the microbiota. The aim of this narrative review is to examine the published literature on the cutaneous and intestinal microbiota in alopecia areata to be able to establish a pathogenic link. In this review, we summarize the influence of the microbiota on the development of alopecia areata. We first introduce the general pathogenic mechanisms that cause alopecia areata to understand the influence that the microbiota may exert and then we summarize the studies that have been carried out on what type of gut and skin microbiota is found in patients with this disease.

Clinical Case of Tofacitinib Therapy in Autoimmune Alopecia in Patient with Ulcerative Colitis

This article presents the clinical case of a patient with a long history of ulcerative colitis. Seven years after the onset of the disease, other autoimmune disorders such as sacroiliitis and alopecia have manifested. Ulcerative colitis is characterized by severe exacerbations, development of steroid resistance, ineffectiveness of mesalazine therapy, and onset of leukopenia when taking azathioprine and 6-mercaptopurine. Janus kinase inhibitor (tofacitinib) administration leads to remission of the disease, reduced activity of ulcerative colitis and sacroiliitis, and a resumption of hair growth was also observed.

TOX Expression in Mycosis Fungoides and Sezary Syndrome

Mycosis fungoides (MF) and Sezary syndrome (SS) are the two most common type of cutaneous T-cell lymphoma (CTCL). Currently, no markers can be clearly related to prognosis or to differential diagnosis between early stages and inflammatory benign diseases (IBD). The thymocyte selection-associated high mobility group box factor (TOX), has been proposed as a possible marker in differential diagnosis between early CTCL stages and IBD. Recently TOX has been related to prognosis. We aimed to investigate whether TOX may be a diagnostic or prognostic marker. MF and SS biopsies between 2010 and 2020 were retrieved. New tissues slides were stained with an anti-TOX antibody, (Clone NAN448B). On each slide, 5 fields were examined at high magnification (400×), to evaluate the percentage of marker-positivity in a quantitative way. Thirty-six patients (12 females and 24 males) and 48 biopsies were collected. Nine patients had multiple biopsies. TOX expression in MF/SS cases showed an increase from early to advanced phases. TOX was not regarded as a prognostic marker due to the absence of significant changes by comparing early MF cases with reactive conditions. TOX statistical significance increased in patients alive with disease and in those dead of disease (p = 0.013 and = 0.0005, respectively) as compared with patients in complete remission. Our results show that TOX should be regarded more as a prognostic than a diagnostic marker.

Gut microbiota characterization in Chinese patients with alopecia areata

BACKGROUND

The gut microbiota is known to play a key role in autoimmune diseases.

OBJECTIVES

To identify and compare the characteristics in the gut microbial composition of patients with alopecia areata (AA) and healthy controls (HCs).

METHODS

In a cross-sectional discovery cohort, we enrolled 33 patients with AA and 35 HCs from the same geographic location in Shanghai, China. The 16S rRNA gene sequencing and bioinformatic analyses were conducted to analyze DNA extracted from the subjects.

RESULTS

The α-diversity of the AA group demonstrated no statistically significant differences compared with the HC group (P > 0.05). However, the overall gut microbial communities in the AA group were distinct from the HCs (P = 0.0096). We also adopted a random forest model to select three AA-associated OTU biomarkers: OTU1237(Achromobacter), OTU257(Megasphaera), and OTU1784(Lachnospiraceae Incertae Sedis).

CONCLUSION

The overall gut microbial composition for AA was distinct from that of HCs. The gut microbial markers we identified may potentially be used for earlier diagnosis and as therapeutic targets.