Antihistone antibodies in linear scleroderma variants

Antibodies to histone in the pediatric population: a retrospective chart review

BACKGROUND

Antibodies to histone have been associated in the adult literature with systemic lupus erythematosus(SLE) and drug induced lupus(DILE). Little data is available regarding the spectrum of pathology that antibodies to histone encompass in the pediatric population. Prior studies suggest an association with SLE, juvenile idiopathic arthritis(JIA), uveitis and linear scleroderma.

METHODS

Patient charts were reviewed that contained positive anti-histone antibody testing during a consecutive three year period. Patient diagnosis along with the presence of: anti-histone antibody titer, ANA, and the presence of other autoantibodies to SSA, SSB, Sm, RNP, dsDNA and chromatin were obtained. The frequency of SLE, JIA and DILE was further investigated in specific subsets.

RESULTS

139 individual charts were reviewed containing 41 different diagnoses. The most common diagnosis was hypermobility arthralgia with 22 patients. The most frequent rheumatologic diagnosis was JIA(nonsystemic) with 19. 13 patients in this study were diagnosed with SLE and 2 with DILE. 18 patients had other autoantibody production, of these, 11 had SLE or DILE. Only one of 62 patients with a weak antihistone antibody titer(1.0-1.5) was diagnosed with SLE. When strong titers are present(> 2.5), the antihistone antibody test was associated with a greater than 50% incidence of an underlying rheumatologic disease and ten times higher incidence of SLE than a weak titer. In regards to the frequency of SLE, there was a statistically significant difference between weak and moderate titers and between weak and strong titers.

CONCLUSION

The presence of anti-histone antibody was observed in a variety of diagnoses in the pediatric population. Overall, the presence of anti-histone antibodies appears to have poor diagnostic utility for any specific condition. However, diagnostic utility for SLE does appear to improve with higher titers, when combined with other autoantibody positivity. Strength of titer did not appear to be a factor for JIA, but was the most frequently observed rheumatologic disease in this study.

Pediatric morphea state-of-the-art literature review: Reframing morphea as a systemic disease

Pediatric morphea is an inflammatory, fibrosing dermatologic disorder. Although morphea may be localized to the skin and subcutaneous tissues, differentiating it from systemic sclerosis, there is increasing evidence that morphea is a manifestation of a systemic inflammatory process, with the potential to involve many organ systems. Given the potential risk for irreversible sequelae, pediatric morphea should be treated early and aggressively. Long-term disease monitoring is essential.

Immunopathogenesis of Pediatric Localized Scleroderma

Localized scleroderma (LS) is a complex disease characterized by a mixture of inflammation and fibrosis of the skin that, especially in the pediatric population, also affects extracutaneous tissues ranging from muscle to the central nervous system. Although developmental origins have been hypothesized, evidence points to LS as a systemic autoimmune disorder, as there is a strong correlation to family history of autoimmune disease, the presence of shared HLA types with rheumatoid arthritis, high frequency of auto-antibodies, and elevated circulating chemokines and cytokines associated with T-helper cell, IFNγ, and other inflammatory pathways. This inflammatory phenotype of the peripheral blood is reflected in the skin via microarray, RNA Sequencing and tissue staining. Research is underway to identify the key players in the pathogenesis of LS, but close approximation of inflammatory lymphocytic and macrophage infiltrate with collagen and fibroblasts deposition supports the notion that LS is a disease of inflammatory driven fibrosis. The immune system is dynamic and undergoes changes during childhood, and we speculate on how the unique features of the immune system in childhood could potentially contribute to some of the differences in LS between children and adults. Interestingly, the immune phenotype in pediatric LS resembles to some extent the healthy adult cellular phenotype, possibly supporting accelerated maturation of the immune system in LS. We discuss future directions in better understanding the pathophysiology of and how to better treat pediatric LS.

Development of minimum standards of care for juvenile localized scleroderma

Juvenile localized scleroderma (jLS), also known as morphea, is an orphan disease. Pediatric guidelines regarding diagnosis, assessment, and management are lacking.Our objective was to develop minimum standards of care for diagnosis, assessment, and management of jLS. A systematic review was undertaken to establish the pediatric evidence for assessment and monitoring of jLS. An expert panel, including members of the Pediatric Rheumatology European Society (PRES) Scleroderma Working Group, were invited to a consensus meeting where recommendations were developed based on evidence graded by the systematic review and, where evidence was lacking, consensus opinion. A nominal technique was used where 75% consensus was taken as agreement. Recommendations for diagnosis, assessment, and management were developed. Due to a lack of pediatric evidence, these were primarily consensus driven. Careful assessment for extra-cutaneous manifestations including synovitis, brain involvement, and uveitis were key features together with joint assessments between Dermatology and Rheumatology to improve and standardize care.

CONCLUSION

Management of jLS is varied. These recommendations should help provide standardization of assessment and care for those with this rare and potentially debilitating condition. What is Known: • Children with juvenile localized scleroderma (jLS) are managed by a number of specialties including pediatric rheumatologists and dermatologists, sometimes in shared clinics. Studies have shown that management varies considerably and that there are notable differences between specialties [1]. • There is very little published guidance on management of jLS. What is new: • These recommendations aim to standardize diagnosis, assessment, and management through review of pediatric evidence and consensus agreement. • Joint review of patients by both pediatric rheumatologists and dermatologists is recommended.

Deimination of linker histones links neutrophil extracellular trap release with autoantibodies in systemic autoimmunity

Autoantibodies to nuclear antigens arise in human autoimmune diseases, but a unifying pathogenetic mechanism remains elusive. Recently we reported that exposure of neutrophils to inflammatory conditions induces the citrullination of core histones by peptidylarginine deiminase 4 (PAD4) and that patients with autoimmune disorders produce autoantibodies that recognize such citrullinated histones. Here we identify histone H1 as an additional substrate of PAD4, localize H1 within neutrophil extracellular traps, and detect autoantibodies to citrullinated H1 in 6% of sera from patients with systemic lupus erythematosus and Sjögren's syndrome. No preference for deiminated H1 was observed in healthy control sera and sera from patients with scleroderma or rheumatoid arthritis. We map binding to the winged helix of H1 and determine that citrulline 53 represents a key determinant of the autoantibody epitope. In addition, we quantitate RNA for H1 histone subtypes in mature human neutrophils and identify citrulline residues by liquid chromatography and tandem mass spectrometry. Our results indicate that deimination of linker histones generates new autoantibody epitopes with enhanced potential for stimulating autoreactive human B cells.-Dwivedi, N., Neeli, I., Schall, N., Wan, H., Desiderio, D. M., Csernok, E., Thompson, P. R., Dali, H., Briand, J.-P., Muller, S., Radic, M. Deimination of linker histones links neutrophil extracellular trap release with autoantibodies in systemic autoimmunity.

Localized scleroderma variants: pharmacologic implications

Scleroderma, a complex syndrome, is a disease with varied, yet presumably related subtypes. We searched articles relating to localized scleroderma. By detailing these similarities and differences we gain increased knowledge. Furthermore, by understanding parallels and dissimilarities, possible mechanisms and interventions should be clarified.

[Unilateral generalized morphea: a case and literature review]

Localized scleroderma is a connective tissue disorder generally involving de entire dermis and usually limited to the subcutaneous tissue; however, it may progress to large indurated plaques, growth retardation, muscle atrophy, and even to flexion deformities or poorly healing ulcers. Unilateral generalized morphea is an extremely rare variant of localized scleroderma which has seldom been reported in the literature. We report the case of a girl who developed unilateral generalized morphea on the right side of the body.