Longitudinal follow-up of mixed connective tissue disease and overlapping autoimmune diseases of childhood onset in the Afro-descendant population of the French West Indies.

INTRODUCTION: Overlap autoimmune syndromes (OAS) and mixed connective tissue disease (MCTD) are rare in children. We performed a retrospective, longitudinal and descriptive study of Afro-Caribbean patients from the French West Indies followed for MCTD and OAS to describe their characteristics and outcomes during childhood. METHODS: Retrospective study from January 2000 to 2023. Listings of patients were obtained from multiple sources: computerized hospital archives and national hospital-based surveillance system, registry of pediatricians and adult specialists in internal medicine and the national registry for rare diseases. MCTD was defined according to Kasukawa's criteria. OAS was defined as overlapping features of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and dermatomyositis/autoimmune myositis (DM/AM). RESULTS: Sixteen patients were included over a 23-year period (10 MCTD and 6 OAS). The incidence was 0.23 per 100,000 children-years. The mean age at diagnosis was 11.9 years old (2.4-17) with median follow up of 7.9 years (2.1-19.6). SLE phenotype was present in the highest, followed by SSc and DM/AM. Patients had an average of three flares during childhood (1-7). A quarter (25%) had symptomatic pulmonary arterial hypertension (PAH). Ninety-four percent received steroids during follow-up and 88% required a corticosteroid-sparing therapy. Three patients (19%) developed SLE after more than 10y of follow-up. There were no death and no chronic organ failure. CONCLUSION: This is the largest pediatric cohort of MCTD and OAS in Afro-descendant patients treated in a country with a high standard of care. The clinical evolution did not differ between MCTD and OAS. The main complication was PAH, more frequent in our cohort.

Juvenile Dermatomyositis in Afro-Caribbean children: a cohort study in the French West Indies.

INTRODUCTION: The epidemiology of Juvenile Dermatomyositis (JDM) in non-Caucasian population is poorly described. We performed a study of patients followed up in the French West Indies for JDM. We aimed to describe clinical and biological specificities during childhood. METHODS: Retrospective study covering the period from Januarys 2000-2023. Listings of patients were obtained from multiple sources, namely computerized hospital archives, registry of referent pediatricians and adult specialists in internal medicine and the French National Registry for rare diseases. JDM and organ involvement were defined according to the international ILAR criteria. RESULTS: Twenty-one patients were included over a 23 year-period. Median age at onset was 8.1 years (Range: 2.5-13.9) with a median follow up of 8 years (Range: 2-19). Two-thirds (14/21) had dysphagia at onset and 33% had respiratory involvement. Thirteen had specific autoantibodies (58%), most frequently anti-Mi-2. The median number of flares during childhood was three (1-9). During childhood, 76% had calcinosis lesions. Clinical evolution seemed to be more aggressive for boys than girls (respectively 4.2 versus 2.2 flares (p = 0.04) and 50% vs 18% needing more than one background therapy, p = 0.03). CONCLUSION: This retrospective study is the largest cohort of pediatric patients of Afro-Caribbean and Black African descent treated for JDM in a high-income health system, and the first to describe the incidence and immunological profile in a population of African descent. They had higher rate of calcinosis and similar respiratory involvement. Overall outcomes during childhood were similar to North America and European countries.

Systemic lupus of pediatric onset in Afro-Caribbean children: a cohort study in the French West Indies and French Guiana.

BACKGROUND: Systemic diseases of pediatric onset are more frequent in the Afro-Caribbean population. We performed a study of patients followed in the French overseas departments of America (FOAD) for pediatric systemic lupus erythematosus (pSLE). The aims were to describe the clinical and biological specificities during childhood in this population. METHODS: A retrospective study was conducted between January 2000 and September 2021. Patients with pSLE were identified from multiple sources: computerized hospital archives, registry of referring pediatricians, adult specialists in internal medicine and the French National Registry for rare diseases. We studied SLE with pediatric onset defined by international criteria. RESULTS: Overall, 2148 patients were identified, of whom 54 were included. The average follow-up was 8.3 years (range: 0.3-25 years). We observed an increase in new diagnoses over time. At onset, pSLE patients had a median of 10 SLICC criteria (range: 4-12), and the median EULAR/ACR 2019 score was 38 (12-54). At onset, one third of patients had renal involvement, 15% had neurolupus and 41% cardiac involvement. During childhood, 54% had renal involvement, and 26% suffered from neurolupus. Patients suffered a median of 3 flares during childhood, and 26% had more than 5 flares. Patients with younger age at onset had worse outcomes than those who were older at diagnosis, i.e., more flares (median 5, p = 0.02) and requiring an average of 4 background therapies (p = 0.04). CONCLUSION: The outcomes of Afro-Caribbean patients were similar to those in Western population, but with worse disease activity at onset. Further studies should be performed to identify the genetic and environmental factors in this population.

ZIKA vasculitis: A new cause of stroke in children?

Viral infectious vasculitis is a cause of stroke in children. Zika virus infection is often asymptomatic. Neurological complications have however been reported: Guillain-Barré, ADEM, meningoencephalitis, myelitis, microcephaly in the fetus of infected mothers. We discuss the case of a child presenting acute infection with ZIKV that was associated with a stroke. A 10-months-old boy without medical history presented after 2days of fever and cutaneous rash, conjunctivitis on day 5, a right hemiparesis on day 6. Brain MRI found an ischemic stroke in the left superficial MCA territory with distal occlusion of left M1 portion of the MCA. Specific real-time reverse PCR detected Zika virus in serum. There are no known cases of cerebral infarction associated with Zika infection. However, cases of cerebral infarcts associated with dengue vasculitis have rarely been described. It has been recently showed that there is a tropism of the Zika virus for endothelial cells. This could be responsible for stroke, possibly particularly in young children.