Exploring the depths of IgG4: insights into autoimmunity and novel treatments.

IgG4 subclass antibodies represent the rarest subclass of IgG antibodies, comprising only 3-5% of antibodies circulating in the bloodstream. These antibodies possess unique structural features, notably their ability to undergo a process known as fragment-antigen binding (Fab)-arm exchange, wherein they exchange half-molecules with other IgG4 antibodies. Functionally, IgG4 antibodies primarily block and exert immunomodulatory effects, particularly in the context of IgE isotype-mediated hypersensitivity reactions. In the context of disease, IgG4 antibodies are prominently observed in various autoimmune diseases combined under the term IgG4 autoimmune diseases (IgG4-AID). These diseases include myasthenia gravis (MG) with autoantibodies against muscle-specific tyrosine kinase (MuSK), nodo-paranodopathies with autoantibodies against paranodal and nodal proteins, pemphigus vulgaris and foliaceus with antibodies against desmoglein and encephalitis with antibodies against LGI1/CASPR2. Additionally, IgG4 antibodies are a prominent feature in the rare entity of IgG4 related disease (IgG4-RD). Intriguingly, both IgG4-AID and IgG4-RD demonstrate a remarkable responsiveness to anti-CD20-mediated B cell depletion therapy (BCDT), suggesting shared underlying immunopathologies. This review aims to provide a comprehensive exploration of B cells, antibody subclasses, and their general properties before examining the distinctive characteristics of IgG4 subclass antibodies in the context of health, IgG4-AID and IgG4-RD. Furthermore, we will examine potential therapeutic strategies for these conditions, with a special focus on leveraging insights gained from anti-CD20-mediated BCDT. Through this analysis, we aim to enhance our understanding of the pathogenesis of IgG4-mediated diseases and identify promising possibilities for targeted therapeutic intervention.

Short-Term Effects Of Dry Heat Treatment (Fluidotherapy) In The Management Of Breast Cancer Related Lymphedema: A Randomized Controlled Study.

BACKGROUND: To investigate whether fluidotherapy added to complete decongestive therapy (CDT) would provide additional contribution to edema reduction in patients with breast cancer related lymphedema (BCRL). MATERIAL AND METHODS: Thirthy-two patients with unilateral BCRL were randomly divided into 2 groups: standard treatment with CDT only (Group 1) and CDT + fluidotherapy (Group 2). All patients underwent phase 1 CDT, which included manual lymphatic drainage, multilayer bandaging, supervised exercises and skin care for a total of 15 sessions, 5 times a week for 3 weeks. Only Group 2 received a total of 15 sessions application of fluidotherapy. Before and after CDT, patients were evaluated for extremity volumes and excess volumes, according to circumferencial measurements of the extremity. Arm pain was evaluated with Visual Analaogue Scale (VAS-Pain). RESULTS: Seventeen patients in Group 1 and 15 patients in Group 2 completed the study. Patients' demographic data and volume measurements were similar at the beginning of the treatment. Limb volumes of both groups were significantly reduced after treatment (P < .001 for both group). Pain significantly decreased (P = .001 for both group). No adverse reactions were recorded. The mean change in volume measurements and VAS-Pain scores of patients in CDT+fluidotherapy group before and after treatment were significantly higher than those in only CDT group (P = .028, P = .020 respectively). CONCLUSION: Fluidotherapy added to CDT reduced pain and edema severity more than standard CDT in the patients with BCRL. As a noninvasive, novel, and effective method, fluidotherapy may be a promising treatment modality for the treatment of lymphedema.

Multiple environmental antigens may trigger autoimmunity in psoriasis through T-cell receptor polyspecificity.

Introduction: Psoriasis is a T-cell mediated autoimmune skin disease. HLA-C*06:02 is the main psoriasis-specific risk gene. Using a Vα3S1/Vß13S1 T-cell receptor (TCR) from a lesional psoriatic CD8+ T-cell clone we had discovered that, as an underlying pathomechanism, HLA-C*06:02 mediates an autoimmune response against melanocytes in psoriasis, and we had identified an epitope from ADAMTS-like protein 5 (ADAMTSL5) as a melanocyte autoantigen. The conditions activating the psoriatic autoimmune response in genetically predisposed individuals throughout life remain incompletely understood. Here, we aimed to identify environmental antigens that might trigger autoimmunity in psoriasis because of TCR polyspecificity. Methods: We screened databases with the peptide recognition motif of the Vα3S1/Vß13S1 TCR for environmental proteins containing peptides activating this TCR. We investigated the immunogenicity of these peptides for psoriasis patients and healthy controls by lymphocyte stimulation experiments and peptide-loaded HLA-C*06:02 tetramers. Results: We identified peptides from wheat, Saccharomyces cerevisiae, microbiota, tobacco, and pathogens that activated both the Vα3S1/Vß13S1 TCR and CD8+ T cells from psoriasis patients. Using fluorescent HLA-C*06:02 tetramers loaded with ADAMTSL5 or wheat peptides, we find that the same CD8+ T cells may recognize both autoantigen and environmental antigens. A wheat-free diet could alleviate psoriasis in several patients. Discussion: Our results show that due to TCR polyspecificity, several environmental antigens corresponding to previously suspected psoriasis risk conditions converge in the reactivity of a pathogenic psoriatic TCR and might thus be able to stimulate the psoriatic autoimmune response against melanocytes. Avoiding the corresponding environmental risk factors could contribute to the management of psoriasis.

Evaluating dietary considerations in hidradenitis suppurativa: a critical examination of existing knowledge.

Hidradenitis suppurativa (HS) is a chronic condition that can overwhelm patients, and the effectiveness of supplementary dietary treatments remains uncertain. The primary aim of this review is to explore the connection between diet and HS progression. However, it is imperative to note that the evidence supporting a substantial role of the diet in HS remains weak. Dietary alterations alone should not be considered independent solutions for managing HS. Medical therapy continues to be indispensable for adequate treatment. Research indicates that the Mediterranean lifestyle and diet may provide cost-effective and beneficial adjustments when combined with traditional therapies. Conversely, foods with a high glycemic index and dairy could worsen HS symptoms, conceivably through mechanisms linked to insulin resistance and inflammation. Zinc, known for its antioxidant properties, shows promise as an adjunct therapy. Moreover, evidence suggests a connection between vitamin D deficiency and HS severity, although the findings are inconclusive. Brewer's yeast-free diet, B12 supplementation, intermittent fasting, and reducing the intake of refined sugar and dairy merit further investigation. In conclusion, this review highlights the need for additional research because of the lack of standardized reporting of clinical effects in the studies under scrutiny. A deeper exploration of the pathophysiology focusing on dietary modifications and their potential associations with HS severity is essential. Furthermore, it is crucial to recognize that patients' willingness to experiment with new diets makes them vulnerable to fraudulent interventions, highlighting the importance of evidence-based dietary guidance.

Successful infliximab treatment in siblings with Netherton syndrome: Unveiling a novel SPINK5 gene variant and literature review.

Netherton syndrome (NS) is a rare autosomal recessive genodermatosis. In this article, we present two siblings with NS who harbour a novel variant in the SPINK5 gene and were treated with infliximab infusions. Both patients exhibited the characteristic clinical triad of NS, and their whole exome sequencing analysis revealed a homozygous variant, c.1820+53G>A, in the SPINK5 gene. Notably, this is the first documented instance of homozygosity for this particular variant. Despite the absence of a specific treatment, both patients achieved total clearance of the skin lesions, and a significant decrease in total IgE levels was documented.

Oral mucosa involvement in pediatric patients with xeroderma pigmentosum: a comprehensive review.

BACKGROUND: Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder presenting with an inability to repair UV-induced DNA damage. This can lead to the development of neoplasms affecting multiple organ systems, with onset often in childhood. Unfortunately, no cure currently exists for XP, and management strategies focus on sun protection and early intervention for malignancies. Although most skin problems in XP patients are UV induced, various oral lesions are also described. However, the literature has not extensively characterized the oral manifestations and their prognostic significance. METHODS: We conducted a comprehensive review to evaluate the prevalence and nature of oral mucosal lesions in pediatric XP patients. RESULTS: Our literature search yielded 130 pediatric XP patients with oral involvement and 210 associated tumoral or non-tumoral lesions. Squamous cell carcinoma was the most common type of oral mucosal tumor reported, with other malignancies including basal cell carcinoma, melanoma, angiosarcoma, fibrosarcoma, and trichilemmal carcinoma. CONCLUSION: Given the potential morbidity and mortality associated with oral mucosal tumors in XP patients, our study aims to raise awareness of these manifestations. Early diagnosis and treatment are crucial for managing these lesions effectively, and routine oral exams should be considered a critical component of dermatological evaluations for XP patients, especially in the pediatric age group.

Isotretinoin-associated acne fulminans: A multicentre, retrospective study of the European Academy of Dermatology and Venereology Task Force on Acne, Rosacea and Hidradenitis Suppurativa.

BACKGROUND: Acne fulminans (AF) is a rare severe acne entity. Although occasionally reported, it is unclear whether AF development is associated with oral isotretinoin treatment. OBJECTIVES: To investigate the occurrence of isotretinoin-associated AF, clinical characteristics and prognosis at follow-up. METHODS: An international, multicentre, retrospective study was performed in eight hospitals following the call of the EADV Task Force on Acne, Rosacea and Hidradenitis Suppurativa (ARHS). Characteristics of patients treated with isotretinoin before the development of AF (isotretinoin-associated acne fulminans, IAF) were compared with non-IAF (NAF). RESULTS: Forty-nine patients diagnosed with AF from 2008 to 2022 were included (mean age 16.4 years, SD 2.9, 77.6% male). Αrthralgias/arthritis occurred in 11 patients (22.9%). AF occurred without any previous acne treatment in 26.5% of the patients. Overall, 28 patients (57.1%) developed AF after oral isotretinoin intake (IAF group), while the remaining 21 patients (42.9%) developed AF without previous oral isotretinoin administration (NAF group). IAF occurred after a median duration of isotretinoin treatment of 45 days (IQR: 30, 90). Patients with IAF were more frequently male compared to patients with NAF (89.3% vs. 61.9%, respectively, p = 0.023). There were no differences in patients with IAF versus NAF in patient age, the duration of pre-existing acne, a family history of AF, the distribution of AF lesions or the presence of systemic symptoms or arthralgias. Regarding the management of AF, patients with IAF were treated more frequently with prednisolone (96.2%) compared to those with NAF (70%; p = 0.033) and less frequently with isotretinoin (32.1%) compared to NAF (85.7%; p < 0.001). At a median follow-up of 2.2 years, 76.4% of patients were free of AF and scarring was present in all patients. CONCLUSIONS: No specific clinical or demographic characteristics of IAF compared with NAF could be detected, a fact that does not support IAF as a district clinical entity.

Behçet's Disease: A Comprehensive Review on the Role of HLA-B*51, Antigen Presentation, and Inflammatory Cascade.

Behçet's disease (BD) is a complex, recurring inflammatory disorder with autoinflammatory and autoimmune components. This comprehensive review aims to explore BD's pathogenesis, focusing on established genetic factors. Studies reveal that HLA-B*51 is the primary genetic risk factor, but non-HLA genes (ERAP1, IL-10, IL23R/IL-12RB2), as well as innate immunity genes (FUT2, MICA, TLRs), also contribute. Genome-wide studies emphasize the significance of ERAP1 and HLA-I epistasis. These variants influence antigen presentation, enzymatic activity, and HLA-I peptidomes, potentially leading to distinct autoimmune responses. We conducted a systematic review of the literature to identify studies exploring the association between HLA-B*51 and BD and further highlighted the roles of innate and adaptive immunity in BD. Dysregulations in Th1/Th2 and Th17/Th1 ratios, heightened clonal cytotoxic (CD8+) T cells, and reduced T regulatory cells characterize BD's complex immune responses. Various immune cell types (neutrophils, γδ T cells, natural killer cells) further contribute by releasing cytokines (IL-17, IL-8, GM-CSF) that enhance neutrophil activation and mediate interactions between innate and adaptive immunity. In summary, this review advances our understanding of BD pathogenesis while acknowledging the research limitations. Further exploration of genetic interactions, immune dysregulation, and immune cell roles is crucial. Future studies may unveil novel diagnostic and therapeutic strategies, offering improved management for this complex disease.

Evaluation of the effect of pitavastatin on motor deficit and functional recovery in sciatic nerve injury: A CatWalk study.

Objectives: This study aims to investigate the electrophysiological, scintigraphic, and histopathological effects of pitavastatin and its impact on functional status in rats with sciatic nerve injury. Materials and methods: A total of 30 Wistar albino rats were divided into three equal groups including 10 rats in each group: sham group (no injury), control group (nerve injury induced), and pitavastatin group (nerve injury induced and 2 mg/kg of pitavastatin administered orally once a day for 21 days). Before and at the end of intervention, quantitative gait analysis with the CatWalk system and sciatic nerve conduction studies were performed. After the intervention, the gastrocnemius muscle was scintigraphically evaluated, and the sciatic nerve was histopathologically examined. Results: There was no significant difference in the sciatic nerve conduction before the intervention and Day 21 among the groups (p>0.05). According to the quantitative gait analysis, there were significant differences in the control group in terms of the individual, static, dynamic, and coordination parameters (p<0.05). The histopathological examination revealed a significant difference in the total myelinated axon count and mean axon diameter among the groups (p<0.001). Conclusion: Pitavastatin is effective in nerve regeneration and motor function recovery in rats with sciatic nerve injury.

Risk of skin cancers in mycosis fungoides patients receiving PUVA therapy: A real-life experience from a single tertiary center.

BACKGROUND: Mycosis fungoides (MF) is the most common cutaneous T-cell lymphoma. Skin-directed therapies, including phototherapy, are the first-line treatment modalities. Psoralen plus ultraviolet A light photochemotherapy (PUVA) is quite effective in controlling the disease; however, long-term adverse effects, particularly carcinogenesis, are the cons of this treatment. OBJECTIVE: There are various studies on the negative impact of PUVA on skin cancer in patients with autoimmune skin diseases. The data on the long-term effects of phototherapy on MF patients are scarce. METHODS: All MF cases that received PUVA alone or combined with other treatments at a single tertiary center were analyzed. This study compared the development of non-melanoma skin cancers, melanoma, and solid organ tumors in MF patients with at least 5-year follow-up data with age- and sex-matched controls. RESULTS: A total of 104 patients were included in the study. Ninety-two malignancies were detected in 16 (15.4%) patients, and six developed multiple malignancies. Skin cancers consisted of 56 basal cell carcinomas, 16 Bowen's disease, four squamous cell carcinomas, three melanomas, two basosquamous cell carcinomas, one Kaposi sarcoma, and one keratoacanthoma were found in nine (8.7%) patients. Eight patients developed three solid cancers and six lymphomas. The risk of developing skin cancer was associated with the total number of PUVA sessions (<250 vs ≥250 sessions; hazard ratio (HR) 4.44, 95% confidence interval (CI) 1.033-19.068; p = .045). 9 (13.2%) of 68 patients who had follow-ups for at least 5 years developed skin cancer. Compared to an age- and sex-matched cohort, the prevalence of new skin cancer was considerably greater (p = .009). CONCLUSIONS: Patients with MF are predisposed to develop secondary malignancies, and continual exposure to PUVA may potentiate this risk. Annual digital dermoscopic follow-up in MF patients treated with UVA is advised for early diagnosis and treatment of secondary cutaneous malignancies.

EULAR study group on 'MHC-I-opathy': identifying disease-overarching mechanisms across disciplines and borders.

The 'MHC-I (major histocompatibility complex class I)-opathy' concept describes a family of inflammatory conditions with overlapping clinical manifestations and a strong genetic link to the MHC-I antigen presentation pathway. Classical MHC-I-opathies such as spondyloarthritis, Behçet's disease, psoriasis and birdshot uveitis are widely recognised for their strong association with certain MHC-I alleles and gene variants of the antigen processing aminopeptidases ERAP1 and ERAP2 that implicates altered MHC-I peptide presentation to CD8+T cells in the pathogenesis. Progress in understanding the cause and treatment of these disorders is hampered by patient phenotypic heterogeneity and lack of systematic investigation of the MHC-I pathway.Here, we discuss new insights into the biology of MHC-I-opathies that strongly advocate for disease-overarching and integrated molecular and clinical investigation to decipher underlying disease mechanisms. Because this requires transformative multidisciplinary collaboration, we introduce the EULAR study group on MHC-I-opathies to unite clinical expertise in rheumatology, dermatology and ophthalmology, with fundamental and translational researchers from multiple disciplines such as immunology, genomics and proteomics, alongside patient partners. We prioritise standardisation of disease phenotypes and scientific nomenclature and propose interdisciplinary genetic and translational studies to exploit emerging therapeutic strategies to understand MHC-I-mediated disease mechanisms. These collaborative efforts are required to address outstanding questions in the etiopathogenesis of MHC-I-opathies towards improving patient treatment and prognostication.

The clinical and demographical characteristics of Turkish pediatric lymphedema patients: a multicenter study.

BACKGROUND: Reducing lymphedema-associated burden and disability in the pediatric setting requires improved awareness and understanding clinical properties of the lymphedema. The aim of this study was to evaluate the clinical and demographic characteristics of patients with pediatric lymphedema presented to different lymphedema centers in Turkey. METHODS: The socio-demographic and clinical characteristics of the children including age, gender, presence of genetic syndromes, duration of edema, site and stage of lymphedema and the received therapies were determined. Parental and children education on self-management techniques were recorded. RESULTS: A total of 122 children (female: 66, male: 56) with a mean age of 120.7 ± 71.2 months were included from 7 centers. Of them; 92% had primary, 8% had secondary lymphedema mostly due to infection and trauma. Lymphedema was part of a syndrome in 18% of the children. The most common site of involvement was the lower extremity, followed by upper extremity and genital involvement. Lymphedema was complicated in 17 % of children, mainly with a clinical picture of cellulitis, infection, and pain. The median duration of lymphedema was 41 (5-216) months. Although most of the children had stage 2 lymphedema, only 40% of them received treatment. The most commonly received treatment was compression therapy. No family or child was educated for self- care management before. DISCUSSION: In conclusion, pediatric lymphedema has a comparable gender distribution and usually involves the lower extremities. Although most of the children had advanced disease, more than half of the patients did not receive any treatment indicating the unmet need for management of lymphedema. The education of patients and/or children about self-management methods were lacking. We suggest educational activities for both families of children with lymphedema and health care providers, in order to facilitate early reference to lymphedema units and to receive prompt preventive and therapeutic approaches for this suffering condition.

Effect of Perineural Dextrose Injection on Ulnar Neuropathy at the Elbow: A Randomized, Controlled, Double-Blind Study.

OBJECTIVE: To compare perineural dextrose injection efficacy in the treatment of ulnar neuropathy at the elbow with a control group. DESIGN: Prospective double-blind randomized control study. SETTING: Training and research hospital. PARTICIPANTS: The study was completed with 40 patients with ulnar neuropathy at the elbow. INTERVENTION: Normal saline (0.9% sodium chloride) was injected in patients in the control group (n=20; mean age=38.1±10.7 years; median duration of symptoms=4.5 months), and 5% dextrose was injected in patients in the dextrose group (n=20; mean age=43.6±13.5 years; median duration of symptoms=5 months), perineurally under ultrasound guidance twice at 2-week intervals. Ultrasound-guided perineural injection of 1 cc each was administered into the ulnar nerve, 2 cm and 4 cm distal to the medial epicondyle, at the level of the medial epicondyle, and 2 cm and 4 cm proximal to the medial epicondyle. The amount of total fluid injected was 5 cc. MAIN OUTCOME MEASURE(S): At baseline and weeks 2, 4, and 12, the patients were evaluated with the Visual Analog Scale for pain and the Disabilities of the Arm Shoulder and Hand questionnaire for disability. Electrophysiological evaluation was performed with ulnar nerve conduction studies, and the ulnar nerve cross-sectional area was measured on ultrasonography. RESULTS: The improvements in pain, disability, ulnar motor nerve velocity, and ulnar nerve cross-sectional area in the dextrose group were superior to those in the control group, especially at weeks 4 and 12 (P<.001, using independent samples t tests). CONCLUSION: Perineural 5% dextrose may be an effective alternative therapy for those with ulnar neuropathy at the elbow for up to the 12th week.

Phenotypic and molecular characterization of five patients with PIK3CA-related overgrowth spectrum (PROS).

Somatic and germline PI3K-AKT-mTOR pathway pathogenic variants are involved in several segmental overgrowth phenotypes such as the PIK3CA-related overgrowth spectrum (PROS), Proteus syndrome, and PTEN hamartoma tumor syndrome. In this study, we describe five patients with PROS. We identified by high-throughput sequencing four different somatic PIK3CA pathogenic variants in five individuals. The Glu726Lys variant, which was previously reported in megalencephaly-capillary malformation-polymicrogyria (MCAP) syndrome, was identified in two patients with unclassified PROS. The Cys420Arg substitution, which was previously reported in CLOVES, was found in a patient with fibroadipose hyperplasia. Additionally, relatively rare pathogenic variants, His1047Tyr and Tyr1021Cys, were detected in two patients with MCAP. Therefore, we suggest performing deep sequencing of PIK3CA in all patients with suspected PROS, instead of targeted polymerase chain reaction for hotspot pathogenic variants.

Therapeutic outcomes of one-minute application of sodium hydroxide versus phenol in the chemical cauterization of ingrown toenails.

BACKGROUND: Ingrown nails are frequently encountered in dermatology practice. The recurrence tendency of the disorder makes chemical cauterization essential during surgical procedures. In studies comparing nail matrix cauterization with sodium hydroxide (NaOH) versus phenol, phenol's application time was highly variable. OBJECTIVE: To compare the therapeutic outcomes of matrix cauterization for a standard duration of one minute for NaOH versus phenol in stage II and III ingrown nails. MATERIAL AND METHODS: The medical records of patients undergoing matrix cauterization with 10% NaOH or 88% phenol were evaluated. The primary outcome measure was the lack of recurrences on long-term follow-up. The secondary outcome measures were complete healing duration, patient-reported pain scores, and adverse effects related to the procedure. RESULTS: Enrolled in this study were 62 ingrown toenail sides treated with 10% NaOH and 56 ingrown toenail sides treated with 88% phenol. The mean follow-up duration was 25.17 months. Recurrence was observed in four nail sides of the NaOH group (%6.45) and three nail sides of the phenol group (%5.35). The difference between the recurrence rates did not reach statistical significance. Patients treated with both methods were free of pain on the post-procedural tenth day. The visual analog scale pain scores and complete healing duration were similar between the two groups (p>0.05). CONCLUSION: In a large group with long-term follow-up results, the short-term and long-term post-operative treatment outcomes were similar between the one-minute applications of 10% NaOH versus 88% phenol groups.

COVID-19-related oral mucosa lesions among confirmed SARS-CoV-2 patients: a systematic review.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus responsible for coronavirus disease 2019 (COVID-19), which manifests as a flu-like respiratory infection affecting multiple organ systems, including the gastrointestinal system, central nervous system, cardiovascular system, skin, and mucosa. In this review, we investigated the literature on specific manifestations of COVID-19 in the oral mucosa. An online literature search in PubMed, Scopus, Google Scholar, and Medline was conducted to retrieve relevant studies on confirmed COVID-19 patients with oral mucosa findings published between December 31, 2019, and April 07, 2021. After an independent review by two authors, 39 articles considering 59 laboratory-confirmed cases of SARS-CoV-2 infection were included in the final analysis. The most common finding, reported in 29 patients (43.9%), was Kawasaki-like syndrome. In addition, oral ulcers including aphthous, hemorrhagic, and necrotic ulcers were reported in 24 patients (36.3%). Other lesions reported included pustules, macules, bullae, maculopapular enanthema, and erythema multiforme-like lesions. Concomitant skin lesions were present in 60.6% of patients. Fever was reported in 86.2% of patients. Forty-eight patients (76.1%) were hospitalized. Loss of taste and smell was present in 30.8% of the patients. A comprehensive understanding of the dermatologic manifestations of COVID-19 can improve and facilitate patient management and referrals.