Background and objective Nail disorders encompass a wide spectrum of conditions, spanning congenital, developmental, infectious, neoplastic, degenerative, dermatological, and systemic diseases. A comprehensive exploration of their clinical manifestations, incidence, and associations is crucial for precise diagnosis and effective management. Methods This observational cross-sectional study conducted at B.J. Medical College and Civil Hospital, Ahmedabad involved 300 consecutive patients with nail changes from July 2017 to June 2019 reporting diverse dermatological and systemic conditions. The inclusion criteria involved patients of both genders and all age groups displaying nail changes associated with dermatological and systemic diseases. Data collection entailed a comprehensive clinical history, systemic and dermatological examinations, nail assessment using Dermoscope (DermLite 3, 10x), and supplementary tests. Analyses were performed on Microsoft Excel 2007 software. The study was approved by the Institute Ethics Committee. Results Among the 300 cases, females had a higher prevalence of nail involvement (57%), with a female-to-male ratio of 1.3:1. The most affected age group was 21-40 years, with 6-10 nails typically affected. Notably, housewives showed a higher prevalence. The most frequent nail condition was onychomycosis (24.33%) followed by psoriatic nail changes (20%). Less frequent nail changes involved eczema (5.7%), paronychia (5%), drug-induced (4.3%), lichen planus (3.7%), trauma-induced (3%), twenty nail dystrophy (2.33%), Darier\'s disease (2%), pemphigus vulgaris (2%), alopecia areata (1.67%), median Heller dystrophy (1.33%), atopic dermatitis (1%), epidermolysis bullosa (1%), racquet nail (1%), leprosy (1%), pityriasis rubra pilaris (0.67%), vitiligo (0.67%), secondary syphilis (0.67%), pachyonychia congenita (0.67%), as well as a case each of total leukonychia, subungual warts, Koenen tumor, and periungual fibroma(0.33%). Systemic autoimmune connective tissue disorders (CTD) accounted for 9%; the most common nail finding observed was nail fold erythema (48.1%) followed by nail fold telangiectasis (44.4%). In systemic sclerosis (SS), the most common finding was nail fold telangiectasia, and in systemic lupus erythematosus (SLE), the most common was nail fold erythema. Scleroderma capillary pattern on nail fold capillaroscopy was found in seven patients with SS, two patients with dermatomyositis, and only one patient with SLE. Nail changes observed in systemic diseases include onychomycosis in diabetes mellitus and chronic renal failure patients, splinter hemorrhages in ischemic heart disease and hypertension, longitudinal melanonychia in HIV, and koilonychia and platynychia in iron deficiency anemia. Other systemic diseases, such as Addison\'s disease and renal failure, also exhibited various nail changes. Conclusions Beyond their cosmetic importance, nails hold a vital pathologic role. Proficiency in nail terminology and classification is key for skillful evaluation. Understanding normal and abnormal nail variants, along with their disease associations, benefits diagnosis and tailored management. Nails, often overlooked but accessible, serve as a window into patients\' general health and should be an integral part of thorough examinations. This study highlights an intricate clinical panorama of nail disorders, highlighting their significant role in both dermatological and systemic contexts.

Diagnosis of autoimmune diseases is in most cases challenging for clinicians as there is not a single specific laboratory or histological marker to diagnose or exclude the presence of the conditions. This review focused on the current knowledge of the role of autoantibodies\' testing in various diseases, such as systemic lupus erythematosus, rheumatoid arthritis, antiphospholipid syndrome, undifferentiated connective tissues disease, primary biliary cholangitis and primary sclerosing cholangitis. Similarly, the prognostic and diagnostic values of autoantibodies testing in patients with interstitial lung disease have been reviewed. In-depth research on the molecular action of these autoantibodies on immune regulation and diseases pathogenesis has been explored beyond their correlation with disease phenotypes, highlighting the impact of autoantibodies targeting on disease outcomes and etiopathogenesis.

BACKGROUND: Connective tissues diseases (CTDs) are a heterogeneous group of disorders that share certain clinical characteristics and disturbed immunoregulation. Interstitial lung diseases (ILDs), also known as diffuse parenchymal lung diseases, are among the most serious pulmonary complications associated with CTDs. Interleukin 9 (IL-9), IL-4 and interferon γ (IFN-γ) - cytokines with important roles in autoimmune disease - were studied in CTD patients and CTD-ILD patients.
METHODS: Sixty-one hospitalized untreated CTD patients were recruited, and 20 healthy volunteers were enrolled as controls. The 61 CTD patients were divided into a simple CTD group and a CTD-ILD group, and the plasma protein IL-9, IL-4 and IFN-γ levels were measured by enzyme-linked immunosorbent assay (ELISA).
RESULTS: The results indicate that the serum IL-9 levels were significantly higher in CTD-ILD and simple CTD patients than they were in healthy controls (each p < 0.05) and that the levels were elevated in CTD-ILD patients compared with simple CTD patients (p < 0.05). The IL-4 levels were higher in CTD-ILD patients than they were in the simple CTD patients (p < 0.05) and healthy controls (p < 0.01). In addition, the serum IL-9 levels were negatively correlated with the level of IFN-γ (r (2) = 0.34, p = 0.01), the estimated percentage of predicted forced vital capacity (FVC%) (r (2) = 0.36, p = 0.00) and the estimated percentage of predicted diffusing capacity (DLCO%) (r (2) = 0.27, p = 0.04) and were positively correlated with the IL-4 level (r (2) = 0.31, p = 0.01).
CONCLUSIONS: Interleukin-9 may play an important role in the pathogenesis of CTD and may contribute to the progression of interstitial lung injury in CTD patients.