John D. Pauls

The specificity of juvenile rheumatoid arthritis (JRA) sera for histone subclasses was examined by immunoblotting. Antibodies to H1 alone were found in 4 of 21 pauciarticular‐onset JRA sera, 4 of 19 polyarticular‐onset JRA sera, and 2 of 11 systemic‐onset JRA sera. Antibodies to H5 alone were found in 1 of 21 pauciarticular JRA sera, 1 of 19 polyarticular JRA sera, and 3 of 11 systemic JRA sera. Antibodies to both H1 and H5 were found in 4 of 21 pauciarticular JRA sera, 4 of 19 polyarticular JRA sera, and 1 of 11 systemic JRA sera. Antibodies to the core histones (H2A and H2B) were found in 1 of 21 pauciarticular JRA sera, 1 of 19 polyarticular JRA sera, and no systemic JRA sera. No reactivity to histones was observed in 30 sera from age‐matched children with nonrheumatic diseases. The presence of H1 and H5 antibodies did not correlate with antinuclear antibody titers or with a homogeneous pattern of immunofluorescence. The predominance of H1 and H5 antibodies and relative absence of antibodies binding to core histones in JRA contrast with findings in adult systemic lupus erythematosus. Further, the presence of antibodies to H5 alone in some of the JRA patients indicates that the immune response in these patients is directed to determinants that are not shared by sequences of mammalian proteins.

Within the general category of mastocytosis lies an array of clinical presentations with differing prognostic implications. We report 3 cases of systemic mastocytosis distinguished by novel aspects of the disease. Case 1 documents the first successful orthotopic liver transplantation in a patient with mastocytosis; case 2 depicts a potential hereditary component of mastocytosis; and case 3 documents the progression of mastocytosis with hematologic abnormality to mast cell leukemia. Future investigations, such as the early definition of c-kit receptor mutations, may provide additional insight as to the molecular basis for this heterogeneous disease and guidance for prognostic implications and targeted therapies.