Anti‐Ku antibody‐positive systemic sclerosis‐polymyositis overlap syndrome in an adolescent

Abstract

Systemic sclerosis-polymyositis overlap syndrome is rare in children. Anti-PM/Scl is the most common autoantibody associated with this syndrome. We present a case of systemic sclerosis-polymyositis overlap syndrome in a child with isolated anti-Ku antibodies, an uncommon antibody associated with this rare syndrome. | 961 Pediatric Dermatology BRIEF REPORT the clinical features and outcome of children with this antibody are limited, with only six previously reported pediatric cases of anti-Ku antibody-positive overlap syndrome. 2-6 Including our patient, all seven children had myositis. Five also had SSc, three had articular disease, two had SLE, two had Raynaud phenomenon, one had overlap of SSc, SLE, and myositis, and one developed ILD. Additional skin findings included 2 with generalized morphea, 2 with malar erythema, 1 with pernio-like erythema of the hands and feet, 1 with facial discoid lesions, and 1 with heliotrope rash of the eyelids. These findings suggest that the clinical manifestations in children and adults with anti-Ku antibody are similar. Anti-Ku-associated SSc-myositis overlap syndrome is rare in children. Our report underscores the importance of testing for anti-Ku antibodies specifically in patients with myositis and SSc suggestive of this syndrome.

Systemic Sclerosis-Specific Antibodies: Novel and Classical Biomarkers

“…Finally, in an Italian study, 13 out of the 46 Ku-positive patients presented a diagnosis of the SSc spectrum diseases (including PM/SSc, DM/SSc and SSc): all displayed a limited cutaneous involvement with a higher prevalence of myositis, arthritis, and ILD [ 121 ]. Anti-Ku is rarely found in SSc children or adolescents, and, in fact, only seven cases of overlap syndrome are described, all presenting with myositis and with only one case of ILD [ 122 ].…”