Background. Systemic reactions after Hymenoptera sting are a common initial manifestation of clonal mast cell disorders (CMD). Since the majority of these patients lack classical skin lesions, sensitive and expensive diagnostic techniques are needed to make the diagnosis. The Red Espanola de Mastocytosis (REMA) had proposed a score to identify among patients with Hymenoptera venom allergy (HVA) those with high likelihood of having mastocytosis, in order to specifically address the diagnostic work-up. Aims and Methods. To validate the REMA score in an independent large series, we evaluated 98 consecutive patients referred to our Multidisciplinary Mastocytosis Outpatient Clinic for systemic reactions to Hymenoptera and suspect for CMD in the absence of skin lesions. Patients performed bone marrow smears and biopsy, flow cytometry analysis and D816V KIT mutation detection by allele-specific RT-PCR. The diagnosis of mastocytosis was made according the World Health Organization criteria. Results. CMD were diagnosed in 75/98 patients (78.8%), 53 males and 22 females, median age at first observation was 51 years. Indolent Systemic Mastocytosis without skin lesions was diagnosed in 72 patients, the remaining 3 had monoclonal MC activation syndrome, lacking coexpression of CD25 on MC but showing KIT D816V mutation. Notably, 5/8 patients with normal serum basal tryptase (<11.4 ng/mL) had a CMD. As in REMA score, a tryptase level >25 ng/mL, the presence of syncope/presyncope and absence of erythema or angioedema confirmed their predictive power of CMD at univariate analysis. In our series, male gender and tryptase level <15 ng/mL had not independent predictive value. Based on multivariate analysis, we propose a simplified score, considering only 3 variables. Our score showed the same specificity as the original REMA score and the sensitivity was improved from 0.90 to 0.93, thus allowing to foresee the diagnosis of CMD in other 2 patients. Conclusions. A simple clinical score applied to patients with systemic reactions to Hymenoptera venom without skin lesions reliably predicts the presence of underlying CMD and identifies patients for which a complete diagnostic work-up is needed.
A simple score predicts clonal mast cell disorders in patients with systemic reactions to Hymenoptera venom without skin lesions
BONIFACIO, Massimiliano;BONADONNA, PATRIZIA;ARTUSO, ANNA;PERBELLINI, Omar;ZANOTTI, ROBERTA
2013-01-01
Abstract
Background. Systemic reactions after Hymenoptera sting are a common initial manifestation of clonal mast cell disorders (CMD). Since the majority of these patients lack classical skin lesions, sensitive and expensive diagnostic techniques are needed to make the diagnosis. The Red Espanola de Mastocytosis (REMA) had proposed a score to identify among patients with Hymenoptera venom allergy (HVA) those with high likelihood of having mastocytosis, in order to specifically address the diagnostic work-up. Aims and Methods. To validate the REMA score in an independent large series, we evaluated 98 consecutive patients referred to our Multidisciplinary Mastocytosis Outpatient Clinic for systemic reactions to Hymenoptera and suspect for CMD in the absence of skin lesions. Patients performed bone marrow smears and biopsy, flow cytometry analysis and D816V KIT mutation detection by allele-specific RT-PCR. The diagnosis of mastocytosis was made according the World Health Organization criteria. Results. CMD were diagnosed in 75/98 patients (78.8%), 53 males and 22 females, median age at first observation was 51 years. Indolent Systemic Mastocytosis without skin lesions was diagnosed in 72 patients, the remaining 3 had monoclonal MC activation syndrome, lacking coexpression of CD25 on MC but showing KIT D816V mutation. Notably, 5/8 patients with normal serum basal tryptase (<11.4 ng/mL) had a CMD. As in REMA score, a tryptase level >25 ng/mL, the presence of syncope/presyncope and absence of erythema or angioedema confirmed their predictive power of CMD at univariate analysis. In our series, male gender and tryptase level <15 ng/mL had not independent predictive value. Based on multivariate analysis, we propose a simplified score, considering only 3 variables. Our score showed the same specificity as the original REMA score and the sensitivity was improved from 0.90 to 0.93, thus allowing to foresee the diagnosis of CMD in other 2 patients. Conclusions. A simple clinical score applied to patients with systemic reactions to Hymenoptera venom without skin lesions reliably predicts the presence of underlying CMD and identifies patients for which a complete diagnostic work-up is needed.
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
