Comorbid Conditions Associated with Alopecia Areata: A Systematic Review and Meta-analysis

Causal Relationship and Potential Common Pathogenic Mechanisms Between Alopecia Areata and Related Cancer

Objective

Alopecia areata (AA) is an autoimmune skin disease. Observational studies have reported an association between AA and cancer. However, the causal relationship between AA and cancer has not been reported. We employed a two-sample Mendelian randomization (MR) study to assess the causality between AA and 17 subtypes of cancers.

Methods

We employed a two-sample Mendelian randomization (MR) study to assess the causality between AA and 17 subtypes of cancers. AA and cancers' association genome-wide association study (GWAS) data were collected. The inverse variance weighted (IVW) method was utilized as the principal method in our Mendelian randomization (MR) study, with additional use of the MR-Egger, weighted median, simple mode, and weighted mode methods. After that, we explored the underlying biological mechanisms by Bioinformatic Analysis.

Results

According to our MR analysis, AA has a causal relationship with hepatic bile duct cancer (HBDC, (odds ratio [OR] = 0.944, 95% confidence interval [CI] = 0.896-0.994, P-value = 0.030) and colorectal cancer (CRC, OR = 0.981, 95% CI = 0.963-0.999, P-value = 0.046). AA could decrease the risk of HBDC and CRC. No causal link between AA and other subtypes of cancers was observed. No heterogeneity or pleiotropy was observed. Furthermore, disease-related genes were obtained, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis results showed that the set of genes associated with immunity-inflammatory signaling pathway.

Conclusion

This study provided new evidence of the relationship between AA with HBDC and CRC. AA may play a protective role in both HBDC and CRC progression. This could provide newer avenues for research in search of treatment for HBDC and CRC.

Cardiodermatology: the heart of the connection between the skin and cardiovascular disease

The skin and cardiovascular systems are connected in unique and meaningful ways, and many diseases conventionally considered as being limited to one organ system are more closely related than previously believed. Major cardiovascular diseases and phenomena such as infective endocarditis, congestive heart failure, Kawasaki disease and thromboembolism are associated with specific skin findings, and advances in genetics, immunology and clinical epidemiology show that inflammatory dermatological diseases, such as psoriasis, have serious cardiovascular and cardiometabolic consequences. Additionally, commonly used cardiovascular therapies, such as antihypertensive medications, are associated with important cutaneous adverse effects, including photosensitivity, photocarcinogenesis and eczematous skin reactions. Moreover, systemic dermatological therapies, including retinoids, Janus kinase inhibitors and biologics, can alter the risk of cardiovascular and cardiometabolic diseases. In this Review on cardiodermatology, we provide interdisciplinary insights from dermatology and cardiology that will be of practical use to both cardiologists and generalists who manage cardiovascular and cardiometabolic diseases in patients with dermatological findings or histories. We discuss specific skin findings associated with cardiovascular diseases to aid in diagnosis; important cutaneous adverse effects of common cardiovascular therapies, for the purpose of treatment monitoring; and the effect of dermatological diseases and dermatological treatment on cardiovascular risk.

Complete Blood Collection-based Systemic Inflammation Biomarkers as a Severity Biomarker in Alopecia Areata: A Cross-sectional Study

Previous studies have suggested that alopecia areata (AA) is an organ-specific disease characterized by loss of immune privilege of hair follicles. However, an increasing body of research indicates that it not only affects the skin but may also be accompanied by systemic inflammatory reactions. Therefore, searching for simple and easily available biomarkers to describe the underlying systemic inflammation in AA patients is of great clinical significance. Complete blood collection-based systemic inflammation biomarkers have been shown to be associated with the severity and prognosis of various skin and autoimmune diseases. They involve multiple cell lineages and can reveal different pathways of immune-inflammatory responses. The aim of this study was to investigate the level of complete blood collection-based systemic inflammation biomarkers in patients with AA, and to analyse their relationship with the disease severity. A total of 302 AA patients and 296 healthy controls were included in this study and the neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), systemic immune inflammation index (SII), and white blood cell/lymphocyte ratio (WLR) were calculated. The differences in these indicators between the 2 groups were compared, and the relationship between NLR, PLR, SII, WLR, and the risk of severe AA were analysed. AA patients had higher NLR, SII, and WLR compared with healthy controls (p = 0.004, 0.002, and 0.002 respectively). PLR and SII were higher in the severe AA group compared with the mild-to-moderate AA patients (p = 0.005 and 0.011 respectively). The risk of severe AA increased with the increasing of PLR, SII, NLR, and WLR (p for trend was 0.001, 0.006, 0.022, and 0.021, respectively). The levels of systemic inflammation biomark-ers in AA patients are higher than in healthy people. NLR, PLR, SII, and WLR are risk factors for severe AA, suggesting a close association between systemic inflammation and disease occurrence in AA patients.

Amygdalin ameliorates alopecia areata on C3H/HeJ mice by inhibiting inflammation through JAK2/STAT3 pathway

BACKGROUND

Evidence has demonstrated that Chinese medicine formula Xuefu Zhuyu decoction can markedly promote the formation of new hair in patients and mice with alopecia areata (AA). Amygdalin is one of the active components of Xuefu Zhuyu decoction, but its therapeutic effects and the underlying mechanisms on AA remains largely unrevealed.

PURPOSE

Therefore, this study aims to investigate the therapeutic effects and to probe its molecular mechanisms of inflammation and immune regulation on AA model of C3H/HeJ mice.

STUDY DESIGN

The C3H/HeJ female mice were divided into control, AA, rusolitinib (60 mg/kg), and amygdalin groups (60, 90, and 120 mg/kg, 0.2 ml/10 g, i.g.).

METHODS

The optical microscope was used to observe the feature of the local skin, and the number of lanugo and terminal hair. H&E staining was performed to determine the degree of pathological damage to the skin. ELISA was performed to detect levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in mice serum. Flow cytometry was carried out to analyze the CD4+CD25+FOXP3+, CD4+ and CD8+ of skin tissue. And the levels of CD4+ and CD8+, p-JAK/JAK2, p-STAT3/STAT, and SOCS3 were detected by immunohistochemistry. Western blot and qRT-PCR were employed to examine the expression levels of IL-6, TNF-α, IFN-γ, JAK2, p-JAK, STAT, p-STAT3 and SOCS3 proteins and genes in skin tissues.

RESULTS

Compared with AA group, amygdalin immensely increased the number of vellus hairs and decreased the number of terminal hairs determined by skin microscopy and H&E staining. ELISA, Western blot and qRT-PCR data showed that the levels of IL-6, TNF-α and IFN-γ in serum and skin tissues of AA mice were significantly increased, while amygdalin administration dramatically restrained the contents of the three pro-inflammatory factors. Flow cytometry and immunohistochemistry hinted that amygdalin observably enhanced the number of CD4+CD25+FOXP3+ and CD4+ cells, while inhibited the number of CD8+ positive cells in mice with AA. Moreover, amygdalin signally reduced JAK2/STAT3 pathway-related protein and gene levels in AA mice.

CONCLUSION

Amygdalin could inhibit inflammatory response and improve immune function in the treatment of AA. The underlying molecular mechanism may be related to inhibition of JAK2/STAT3 pathway.

Immune-Mediated and Psychiatric Comorbidities Among Patients Newly Diagnosed With Alopecia Areata

Importance

Alopecia areata (AA) has been associated with multiple comorbidities, yet information regarding the timing of comorbidity development after AA diagnosis is limited.

Objective

To evaluate the prevalence and new-onset incidence of psychiatric and autoimmune comorbidities in patients with AA in the US.

Design, Setting, and Participants

This retrospective cohort analysis used data collected from January 1, 2007, to April 30, 2023, from the Merative MarketScan Research Databases, which contains medical and drug claims data from more than 46 million patients in the US. Data from adolescent and adult patients (aged 12-64 years) diagnosed with AA and patients without AA (ie, controls) were evaluated. For some analyses, patients with AA were matched (1:4) to controls based on sex, age, and geographic region.

Main Outcomes and Measures

Prevalence (at the time of AA diagnosis) and incidence (new onset after AA diagnosis) of psychiatric and autoimmune diseases were reported as percentage of patients. Risk of developing a new-onset psychiatric or autoimmune disease after AA diagnosis was calculated as adjusted hazard ratios (AHRs) with 95% CIs.

Results

At baseline, 63 384 patients with AA and 3 309 107 without AA were identified. After matching, there were 16 512 and 66 048 patients in the AA and control groups, respectively, with a mean (SD) age of 36.9 (13.4) years and 50.6% of whom were female. Compared with the unmatched controls, patients with AA had higher prevalence of psychiatric (30.9% vs 26.8%; P < .001) and autoimmune (16.1% vs 8.9%; P < .0001) comorbidities at AA diagnosis; incidence was also higher in patients with AA (without history of these comorbidities) vs the matched control group. Patients with AA vs controls had a significantly higher risk of developing a psychiatric (AHR, 1.3; 95% CI, 1.3-1.4) or autoimmune (AHR, 2.7; 95% CI, 2.5-2.8) comorbidity.

Conclusions and Relevance

In this cohort study, patients with AA had a higher prevalence of autoimmune and psychiatric comorbidities at AA diagnosis and demonstrated an elevated risk of new-onset autoimmune and psychiatric comorbidities after their diagnosis. These data highlight the most common comorbidities among patients with AA and may help physicians counsel and monitor patients newly diagnosed with AA.

The genetic link between thyroid dysfunction and alopecia areata: a bidirectional two-sample Mendelian randomization study

Background

Although descriptive studies have found an association between thyroid dysfunction (TD) and alopecia areata (AA), however, the causal relationship between TD and AA remains unclear. The purpose of this study is to investigate the causal relationship between the two and the specific directions.

Methods

We performed large-scale, two-sample Mendelian randomization (MR) analyses to examine whether there was an association between TD (such as Graves' disease (GD), Hashimoto's thyroiditis (HT), thyroid cancer (TC), thyroid stimulating hormone (TSH), thyrotropin-releasing hormone (TRH), etc.) and AA. Genome-wide association study (GWAS) summary statistics for TD and AA were from the IEU OpenGwas project. The inverse variance-weighted (IVW) method was used as the primary analysis method to evaluate the causality between TD and AA, supplemented by the weighted median, MR-Egger, simple mode and weighted mode. In addition, sensitivity analyses were performed to assess the reliability of the study results.

Results

Our study found that single nucleotide polymorphisms (SNPs) in HT (IVW OR = 1.396, 95% CI 1.030-1.892, P=0.031) and hypothyroidism (IVW OR = 1.431, 95% CI 1.138-1.799, P=0.002) significantly increased the risk of AA. Reverse MR analysis indicated that genetic susceptibility to AA (β=-0.029, 95%CI=-0.051 to -0.007, P=0.009) may be a risk for TRH. Positive MR analysis observed no statistically significant causal relationship between other TD and AA (IVW P>0.05). Reverse MR analysis also showed no statistically significant association between AA and other TD (IVW P>0.05) other than TRH. Furthermore, additional sensitivity analyses were performed, including a leave-one-out test, a heterogeneity test, and a pleiotropy test to assess the robustness of the results.

Conclusions

This study provides a very comprehensive analysis of the causal relationship between TD and AA, providing convincing genetic evidence to support the causal relationship between TD and alopecia areata. It reveals some causes of AA patients, which is of great significance for the management and treatment of AA patients.

Italian National Registry of Alopecia Areata: an epidemiological study of 699 Italian patients

BACKGROUND

Alopecia areata (AA) is an organ-specific autoimmune disease that affects the hair follicles of the scalp and the rest of the body causing hair loss. Due to the unpredictable course of AA and the different degrees of severity of hair loss, only a few well-designed clinical studies with a low number of patients are available. Also, there is no specific cure, but topical and systemic anti-inflammatory and immune system suppressant drugs are used for treatment. The need to create a global registry of AA, comparable and reproducible in all countries, has recently emerged. An Italian multicentric electronic registry is proposed as a model to facilitate and guide the recording of epidemiological and clinical data and to monitor the introduction of new therapies in patients with AA.

METHODS

The aim of this study was to evaluate the epidemiological data of patients with AA by collecting detailed information on the course of the disease, associated diseases, concomitant and previous events, and the clinical response to traditional treatments. Estimate the impact on the quality of life of patients.

RESULTS

The creation of the National Register of AA has proven to be a valid tool for recording, with a standardized approach, epidemiological data, the trend of AA, response to therapies and quality of life.

CONCLUSIONS

AA is confirmed as a difficult hair disease to manage due to its unpredictable course and, in most cases, its chronic-relapsing course, capable of having a significant impact on the quality of life of patients.

Non-Cicatricial Alopecia and Its Association with Anthropometric Measurements and Nutritional Laboratory Markers

Alopecia constitutes one of the most common dermatological disorders, and its steadily increasing prevalence is a cause for concern. Alopecia can be divided into two main categories, cicatricial/scarring and non-cicatricial/non-scarring, depending on the causes of hair loss and its patterns. The aim of this study was to investigate the relationship between anthropometric and nutritional laboratory parameters in Caucasian adult women and men with non-cicatricial alopecia. A total of 50 patients (37 with non-cicatricial alopecia and 13 healthy controls) were included in the study. Clinical examination and scalp trichoscopy were performed. The anthropometric and nutritional laboratory parameters were collected and analyzed. No statistically significant differences in the laboratory findings were found. The patients with non-cicatricial alopecia were statistically significantly younger as compared to the controls. An elevated risk of hair loss, which was detected among the younger participants, might be associated with a modern lifestyle and the so-called 'Western diet'. It seems safe to assume that suboptimal nutrition and poor eating habits during childhood might constitute risk factors for early hair loss.

Pathogenesis of Alopecia Areata and Vitiligo: Commonalities and Differences

Both alopecia areata (AA) and vitiligo are distinct, heterogenous, and complex disease entities, characterized by nonscarring scalp terminal hair loss and skin pigment loss, respectively. In AA, inflammatory cell infiltrates are in the deep reticular dermis close to the hair bulb (swarm of bees), whereas in vitiligo the inflammatory infiltrates are in the epidermis and papillary dermis. Immune privilege collapse has been extensively investigated in AA pathogenesis, including the suppression of immunomodulatory factors (e.g., transforming growth factor-β (TGF-β), programmed death-ligand 1 (PDL1), interleukin-10 (IL-10), α-melanocyte-stimulating hormone (α-MSH), and macrophage migration inhibitory factor (MIF)) and enhanced expression of the major histocompatibility complex (MHC) throughout hair follicles. However, immune privilege collapse in vitiligo remains less explored. Both AA and vitiligo are autoimmune diseases that share commonalities in pathogenesis, including the involvement of plasmacytoid dendritic cells (and interferon-α (IFN- α) signaling pathways) and cytotoxic CD8+ T lymphocytes (and activated IFN-γ signaling pathways). Blood chemokine C-X-C motif ligand 9 (CXCL9) and CXCL10 are elevated in both diseases. Common factors that contribute to AA and vitiligo include oxidative stress, autophagy, type 2 cytokines, and the Wnt/β-catenin pathway (e.g., dickkopf 1 (DKK1)). Here, we summarize the commonalities and differences between AA and vitiligo, focusing on their pathogenesis.

Characteristics and Management of Patients with Alopecia Areata and Selected Comorbid Conditions: Results from a Survey in Five European Countries

INTRODUCTION

Alopecia areata (AA) is an autoimmune condition that causes non-scarring hair loss and can impose a high psychosocial burden on patients. The presence of comorbid conditions may impact the management of AA in clinical practice. This analysis aims to describe disease characteristics and management of AA in patients with concomitant atopic, autoimmune, and psychiatric comorbid conditions.

METHODS

Data were collected from the Adelphi Disease Specific Programme™, a cross-sectional survey of physicians and their adult patients with AA conducted in France, Germany, Italy, Spain, and the UK between October 2021 and June 2022. Patients' disease severity was based on physician's definition. Physician-reported data on demographics, AA clinical characteristics, comorbid conditions, and information related to AA therapies were analyzed. Analyses were descriptive.

RESULTS

Overall, 239 dermatologists provided data for 2083 patients, of which 558 patients (27%) had at least one atopic, autoimmune, or psychiatric comorbid conditions. The most common comorbid conditions were atopic dermatitis, autoimmune thyroid disease, and anxiety. The mean (standard deviation) patient age for the three comorbidity groups was 37.6 years (12.1) and 56% of the patients were women (n = 313). In the three comorbidity groups, 51%, 50%, and 55% of patients with atopic, autoimmune, and psychiatric comorbidities had severe AA with disease progression reported as worsening in 30%, 28%, and 30%, respectively, whereas in the group with no comorbidities, 37% were described as having severe AA and 21% getting worse. Scalp hair loss was the primary sign reported across the three groups of comorbid conditions (atopic, 91%; autoimmune, 91%; psychiatric, 88%). Patients with preselected comorbidities presented more frequently AA-related signs and symptoms beyond scalp hair loss than patients without comorbid conditions. These patients were also more likely to receive topical calcineurin inhibitors, topical immunotherapy, conventional systemic immunosuppressants, and oral Janus kinase inhibitors for the treatment of their AA.

CONCLUSION

This analysis provided insights into the burden and management of AA in patients presenting with atopic, autoimmune, and psychiatric comorbid conditions in five European countries.

Integrated Safety Analysis of Ritlecitinib, an Oral JAK3/TEC Family Kinase Inhibitor, for the Treatment of Alopecia Areata from the ALLEGRO Clinical Trial Program

BACKGROUND

The ALLEGRO phase 2a and 2b/3 studies demonstrated that ritlecitinib, an oral JAK3/TEC family kinase inhibitor, is efficacious at doses of ≥ 30 mg in patients aged ≥ 12 years with alopecia areata (AA).

OBJECTIVE

The objective of this study was to evaluate the safety of ritlecitinib in an integrated analysis of four studies in AA.

METHODS

Two cohorts were analyzed: a placebo-controlled and an all-exposure cohort. Proportions and study size-adjusted incidence rates (IRs) of adverse events (AEs) of interest and laboratory abnormalities are reported.

RESULTS

In the placebo-controlled cohort (n = 881; median exposure: 169 days), the proportion of ritlecitinib-treated patients with AEs was 70.2-75.4% across doses versus 69.5% in the placebo group; serious AEs occurred in 0-3.2% versus 1.9% for the placebo. A total of 19 patients permanently discontinued due to AEs (5 while receiving the placebo). In the all-exposure cohort (n = 1294), median ritlecitinib exposure was 624 days [2091.7 total patient-years (PY)]. AEs were reported in 1094 patients (84.5%) and serious AEs in 57 (4.4%); 78 (6.0%) permanently discontinued due to AEs. The most common AEs were headache (17.7%; 11.9/100 PY), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive test (15.5%; 9.8/100 PY), and nasopharyngitis (12.4%; 8.2/100 PY). There were two deaths (breast cancer and acute respiratory failure/cardiorespiratory arrest). Proportions (IRs) were < 0.1% (0.05/100 PY) for opportunistic infections, 1.5% (0.9/100 PY) for herpes zoster, 0.5% (0.3/100 PY) for malignancies (excluding nonmelanoma skin cancer), and 0.2% (0.1/100 PY) for major adverse cardiovascular events.

CONCLUSIONS

Ritlecitinib is well tolerated with an acceptable safety profile up to 24 months in patients aged ≥ 12 years with AA (video abstract and graphical plain language summary available).

TRIAL REGISTRIES

ClinicalTrials.gov: NCT02974868 (date of registration: 11/29/2016), NCT04517864 (08/18/2020), NCT03732807 (11/07/2018), and NCT04006457 (07/05/2019).