Incidence, severity and clinical manifestations of juvenile dermatomyositis among Maori and Pacific Island compared to European children

Calcinosis in Juvenile Dermatomyositis-Epidemiology, Pathogenesis, Clinical Features, and Treatment: A Systematic Review

PURPOSE OF REVIEW

We performed a systematic review of the literature on the epidemiology, pathogenesis, clinical and laboratory characterization, and treatment of calcinosis in patients with juvenile dermatomyositis (JDM). A qualitative systematic review was conducted from January 1975 to April 2023 according to the PRISMA protocol using three electronic databases: PubMed, Web of Science, and Scopus. Studies were analyzed based on the following eligibility criteria: at least one combination of the terms described in the search strategy appeared in the title, written in English, Portuguese, or Spanish, and addressed the epidemiology, pathogenesis, diagnosis, and treatment of calcinosis in juvenile dermatomyositis. Systematic or scoping reviews, letters, clinical images, book chapters, abstracts, inflammatory myopathy in other connective tissue diseases, idiopathic inflammatory myopathies in adults, and purely qualitative studies were excluded.

RECENT FINDINGS

Seventy-five studies were included. According to the literature, calcinosis is common in women, around five years old, with three years of disease in association with osteoarticular, cutaneous, pulmonary manifestations, and fever. The pathogenesis is still unknown, but the participation of interleukin 1 and 6, tumor necrosis factor alpha, and innate immunity dysregulation seem to be involved. Common autoantibodies are anti-NXP-2, anti-MDA-5, and anti-Mi-2, and their treatment remains controversial. Prospective, randomized, controlled studies are needed to evaluate treatment protocols and map the natural history of this serious complication. Calcinosis seems to be more common in White female children with muscle weakness, fever, arthritis, severe pulmonary, and skin involvement with anti-NXP-2, anti-MDA-5, and anti-Mi-2 autoantibodies. The multitargets and aggressive treatment is recommended.

Epidemiology of the idiopathic inflammatory myopathies

The idiopathic inflammatory myopathies (IIMs) are a heterogeneous group of systemic autoimmune diseases that affect the skeletal muscles and can also involve the skin, joints, lungs and heart. The epidemiology of IIM is obscured by changing classification criteria and the inherent shortcomings of case identification using healthcare record diagnostic coding. The incidence of IIM is estimated to range from 0.2 to 2 per 100,000 person-years, with prevalence from 2 to 25 per 100,000 people. Although the effects of age and gender on incidence are known, there is only sparse understanding of ethnic differences, particularly in indigenous populations. The incidence of IIM has reportedly increased in the twenty-first century, but whether this is a genuine increase is not yet known. Understanding of the genetic risk factors for different IIM subtypes has advanced considerably. Infections, medications, malignancy and geography are also commonly identified risk factors. Potentially, the COVID-19 pandemic has altered IIM incidence, although evidence of this occurrence is limited to case reports and small case series. Consideration of the current understanding of the epidemiology of IIM can highlight important areas of interest for future research into these rare diseases.

The long-term outcome of New Zealand Maori and Pacific Island children diagnosed with childhood onset lupus nephritis

OBJECTIVE

To determine the long-term outcome of Maori and Pacific Island children diagnosed with childhood onset lupus nephritis.

METHOD

A chart review was conducted of children diagnosed with biopsy proven lupus nephritis seen by the Starship Hospital and Kidz First paediatric rheumatology and/or Starship renal services between January 1992 and January 2018. Baseline and follow-up kidney histology, adherence and response to therapy including partial or full renal remission, refractory disease, end-stage kidney disease (ESKD) and mortality were determined.

RESULTS

In a New Zealand cohort of 42 with childhood onset lupus nephritis, Maori and Pacific Island children were significantly more likely to develop class 4 lupus nephritis (RR (95% CI), 11.3 (3.84-49.9), p < 0.0001), demonstrate medication nonadherence (RR (95% CI) 12.4 (3.48-85.7), p < 0.0001) and experience end stage kidney disease (RR (95% CI) 15.7 (2.97-389.3), p = 0.0003) and mortality (RR (95% CI) 11.1 (1.91-280.1), p = 0.005) compared to non-Maori and Pacific Island children. In addition, Maori children with childhood onset lupus nephritis developed chronic histological changes significantly more rapidly than Pacific or Asian children (p = 0.038).

CONCLUSION

Lupus nephritis is more common among Maori and Pacific Island children in New Zealand associated with a significant incidence of end stage kidney disease and mortality, with some Maori children developing rapid histologic disease progression.