Azithromycin anaphylaxis in children.

Allergic reactions associated to the use of macrolides are uncommon; in particular only two cases of anaphylaxis with erithromycin and clarithromycin have been reported to date. The aim of this study was to investigate macrolide-induced anaphylaxis. Between December 2007 and December 2011, 136 consecutive children were referred to the Allergy Unit of A. Meyer Children's Hospital because of a past history of reactions to macrolides. Allergy work-ups were carried out according to the European Network for Drug Allergy protocol. Anaphylaxis was diagnosed according to the clinical criteria proposed by Sampson et al. and graded according to Brown SGA et al. Sixty-six out of 136 patients completed the allergologic work-up and among them we investigated three cases of anaphylaxis due to azithromycin which included one child with anaphylaxis to both clarithromycin and azithromycin. In two of the children with anaphylaxis, the diagnosis was only confirmed with the skin prick test, the third was positive to the Intradermal Test. The azithromycin allergy shows a surprisingly high sensitivity to the in-vivo tests. Moreover, this study shows that cross-reactivity may occur between different macrolidic molecules; it has even been suggested that macrolide allergies are unlikely to be class allergies.

Coding sequence and intron-exon junctions of the c-myb gene are intact in the chronic phase and blast crisis stages of chronic myeloid leukemia patients.

The c-myb gene encodes a transcription factor required for proliferation, differentiation and survival of normal and leukemic hematopoietic cells. c-Myb has a longer half-life in BCR/ABL-expressing than in normal cells, a feature which depends, in part, on PI-3K/Akt-dependent regulation of proteins interacting with the leucine zipper/negative regulatory region of c-Myb. Thus, we asked whether the stability of c-Myb in leukemic cells might be enhanced by mutations interfering with its degradation. We analyzed the c-myb gene in 133 chronic myeloid leukemia (CML) patients in chronic phase and/or blast crisis by denaturing-high performance liquid chromatography (D-HPLC) and sequence analysis of PCR products corresponding to the entire coding sequence and each exon-intron boundary. No mutations were found. We found four single nucleotide polymorphisms (SNPs) and identified an alternatively spliced transcript lacking exon 5, but SNPs frequency and expression of the alternatively spliced transcript were identical in normal and CML cells. Thus, the enhanced stability of c-Myb in CML blast crisis cells and perhaps in other types of leukemia is not caused by a genetic mechanism.