Saretta F, Giovannini M, Mori F, Arasi S, Liotti L, et al.
Frontiers in pediatrics •
The alpha-gal syndrome is an allergic syndrome that comprises two clinical pictures: an immediate hypersensitivity to drugs containing alpha-gal and a delayed hypersensitivity to the ingestion of red mammalian meat. This allergic syndrome is often under-recognized, and patients are mislabeled with diagnosis as spontaneous urticaria or idiopathic anaphylaxis. Even though less frequently, children could also be of interest, especially in tick-endemic areas. In most cases, a positive anamnesis for tick bites months before the onset of symptoms is recorded. The clinical manifestations could range from asymptomatic cases to severe anaphylaxis. The most frequently used diagnostic test is the determination of specific IgE for alpha-gal. Oral provocation test is usually reserved to unclear cases or to verify tolerance after diet. No long-term follow-up studies have been published, although an elimination diet could lead to a decrease of specific IgE for alpha-gal and a possible reintroduction of some avoided foods. This paper provides a literature review, focused on pediatric age, and an evaluation of available diagnostic tests. We analyze the correlation between tick bites and symptom onset and unfold the different clinical pictures to help clinicians to promptly recognized this syndrome. Lastly, we address unmet needs in this specific allergy.
Leoni P, Rupoli S, Salvi A, Sambo P, Cinciripini A, et al.
British journal of haematology •
Sera from patients with myelofibrosis were analysed for circulating antibodies against an antigenic determinant characterized by two molecules of galactose in alpha 1-3 linkage (anti-Gal antibodies). 50% of patients were found to have values above the 90th percentile of the values of control sera chosen as a cut-off. The median level of the antibodies was significantly higher than the value detected in normal controls, but no difference could be found between patients with idiopathic myelofibrosis and those with myelofibrosis associated to a chronic myeloproliferative disorder. Anti-Gal antibodies were found to correlate with disease activity and with platelet count whereas no correlation was detected with other haematological parameters. Furthermore, for evaluation of disease activity, determination of serum anti-Gal antibodies was a sensitive and specific parameter. We conclude that humoral immunity against Gal alpha 1-3Gal may provide a sensitive tool to detect disease activity in patients with idiopathic myelofibrosis and may be important for understanding its pathogenesis.
Gabrielli A, Candela M, Pisani E, Hermann K, Wieslander J, et al.
Clinical and experimental rheumatology •
Sera from 224 patients with systemic sclerosis (scleroderma) were analyzed for circulating antibodies against an antigenic determinant characterized by two molecules of galactose in alpha 1-3 linkage. About 45% of the patients were found to have values above the normal range. The mean antibody level was significantly higher than that found in normal subjects (p less than 0.001) or in patients with primary Raynaud's phenomenon who were included as controls. The mean level of anti-Gal antibodies correlated with the degree of skin and internal organ involvement, as well as with the presence of progression or inflammation. Furthermore, when patients with early onset disease were analyzed, high levels of anti-Gal antibodies were present in the subgroups characterized by evidence of progression or inflammation, whereas patients with stable disease did not differ from the controls. We conclude that humoral immunity against Gal alpha 1-3 Gal is an early feature of scleroderma, may be important for its pathogenesis, and may provide a more sensitive tool to detect disease activity.
Gabrielli A, Candela M, Ricciatti AM, Caniglia ML, Wieslander J
Clinical and experimental immunology •
Employing radioimmunoinhibition assays with distinct oligosaccharides as inhibitors, this study demonstrates that the epitope recognized on mouse laminin by sera from patients with systemic sclerosis (scleroderma) is a terminal galactosyl (alpha 1-3)-galactose disaccharide. The reaction with this alpha-digalactose was further confirmed when the sera were tested in radioimmunoassay (RIA) binding assay and in ELISA with synthetic galactose alpha 1-3 galactose coupled to human serum albumin. The circulating antibody appeared restricted to the IgG class and mostly to the subclass IgG3 and IgG4. Antibodies with the same specificity can be found in patients with American cutaneous leishmaniasis and Chagas disease; however, whilst in these diseases the antibody production is triggered by antigenic determinants present on the surface of the parasites, the events eliciting their appearance in systemic sclerosis are unknown.