Shrimp allergy: analysis of commercially available extracts for in vivo diagnosis

Background: Skin prick testing (SPT) with commercial extracts is the first step in the diagnosis of shrimp allergy, although its clinical efficiency is unknown. Objective: To analyze the clinical usefulness of all commercial crustacean extracts available for SPT in Italy. Methods: We performed a multicenter study of 157 shrimp-allergic patients who underwent SPT with 5 commercial crustacean extracts and with house dust mite (HDM) extract. Commercial extracts were analyzed using SDS-PAGE and compared with a freshly prepared in-house shrimp extract. IgE to Pen a 1/Pen m 1, Pen m 2, and Pen m 4 was determined, and immunoblot analysis was performed on a large number of sera. Results: The skin reactions caused by commercial crustacean extracts were extremely heterogeneous, resulting in 32 clinical profiles, with marked differences in protein content and missing proteins at molecular weights corresponding to those of major shrimp allergens. Only strong Pen a 1/Pen m 1 reactors reacted to both HDM and all 5 commercial extracts in SPT. Most patients, including those who were tropomyosin-negative, reacted to HDM. Patients reacted to a large and variable array of proteins, and IgE reactivity was common at high molecular weights (>50 kDa). Conclusions: The in vivo diagnosis of shrimp allergy must continue to be based on SPT with fresh material. Shrimp-allergic patients frequently react to a number of ill-defined high-molecular-weight allergens, thus leaving currently available materials for componentresolved diagnosis largely insufficient. Mites and crustaceans probably share several allergens other than tropomyosin (AU)

Introducción: Las pruebas cutáneas con extractos comerciales representan el primer paso en el diagnóstico de alergia a gamba, si bien, su eficacia clínica no está bien definida. Objetivos: El objetivo de este estudio fue analizar la utilidad clínica de todos los extractos comerciales disponibles en Italia frente a crustáceos en pruebas cutáneas. Métodos: En un estudio multicéntrico, se incluyeron 157 pacientes alérgicos a gamba a los que se realizaron pruebas cutáneas con cinco extractos comerciales de crustáceos y con ácaros del polvo doméstico. Los extractos comerciales fueron analizados mediante SDS-PAGE y comparados con un extracto de gamba preparado en fresco. Se determinó IgE frente a Pen a 1/Pen m 1; Pen m 2, y Pen m 4; y el análisis mediante inmunoblotting se realizó en un amplio número de sueros. Resultados: Los extractos de gamba comercializados dieron lugar a reacciones cutáneas muy poco homogéneas en 32 perfiles clínicos diferentes; así mismo, mostraron grandes diferencias en contenido proteico y, en algunos casos, a falta de proteína a pesos moleculares correspondientes a alérgenos mayoritarios de gamba. Únicamente los reactores más fuertes a Pen a1 /Pen m 1 reaccionaron tanto a ácaros del polvo de casa como a los cinco extractos comerciales en pruebas cutáneas. La mayoría de los pacientes, incluyendo los negativos a tropomiosina, reaccionaron a los ácaros del polvo. Los pacientes reaccionaron a un amplio y variable array de proteínas y se detectó con frecuencia reactividad de IgE en pesos moleculares altos (>50 kDa). Conclusiones: El diagnóstico in vivo de alergia a gamba todavía debe estar basado en pruebas cutáneas prick con producto fresco. Los pacientes alérgicos a gamba a menudo reaccionan a un número de alérgenos de peso molecular alto poco definido, lo que hace que las moléculas disponibles hoy en día para el diagnóstico por componentes sean muy insuficiente. Ácaros y crustáceos probablemente comparten varios alérgenos además de la tropiomiosina (AU)

Characteristics of patients with allergic polysensitization: the POLISMAIL study.

BACKGROUND: The natural history of respiratory allergy is commonly characterized by a worsening of symptom severity, frequent comorbidity of rhinitis and asthma, and polysensitization to aeroallergens. The polysensitization phenomenon starts since childhood and is rare to find monosensitized adult patients. However, there are few studies investigating the characteristics of polysensitized patients. METHODS: This study was performed on a large cohort of patients with allergic rhinitis (assessed by ARIA criteria) and/or mild to moderate asthma (assessed by GINA). The kind and the number of sensitizations, their patterns, and the relation with quality of life (QoL) measured by the Juniper's RQLQ guestionnaire, were evaluated. RESULTS: Globally 418 patients (50.2% males, 49.8% females, mean age 26.4 years, range 3.5-65 years, 64 smokers, 371 non-smokers) were enrolled: 220 had allergic rhinitis alone, and 198 allergic rhinitis and asthma. The mean number ofsensitizations was 2.6. Three hundred-five patients (73%) had persistent rhinitis (PER), 220 of them with moderate-severe form. There was no significant derence in rate of rhinitis and asthma in monosensitized or polysensitized patients. Most patients were sensitized to pollens, whereas only 24.2% of them were sensitized to perennial allergens. Polysensitization was significantly associated with some issues of QoL, confirming previous findings, but not with number ofsensitizations. CONCLUSIONS: This study provides data confirming for poly-sensitized patients the relevance of ARIA classification of AR. PER is the most common form of AR in this cohort, symptoms are frequently moderate-severe, and asthma is present in about the half of patients with AR.

Outcome of multidrug-resistant tuberculosis in human immunodeficiency virus-infected patients.

Among 324 cases of culture-proven tuberculosis from 1988 to 1996 in a hospital in Milan, Italy, 90 (27.8%) were due to Mycobacterium tuberculosis strains resistant to isoniazid and rifampin. Sixty-one of 69 isolates tested had identical restriction fragment length polymorphism patterns. The prevalent strain tested susceptible only to ethionamide and was also resistant to ethambutol, streptomycin, cycloserine, amikacin, kanamycin, terizodone, ofloxacin, rifabutin, rifapentin, and KRM 1648. The median survival time was 94 days. Multivariate analysis showed a trend toward better outcome in the period 1994-1996 (hazard ratio, 4.16; P<.001), and extrapulmonary localization of tuberculosis was the only other independent predictor of a negative outcome (hazard ratio, 2.1; P = .019). The delay from symptoms to beginning of therapy did not seem to be a determining factor in survival time. Standard antituberculosis therapy with four drugs (isoniazid, rifampin, ethambutol, and pyrazinamide) had a higher efficacy than did other regimens with fewer drugs but without a statistically significant difference.

Sublingual versus injective immunotherapy in grass pollen allergic patients: a double blind (double dummy) study.

BACKGROUND: Injective immunotherapy is a well-known and recognized treatment for allergic diseases, but its safety has been questioned during recent years. Alternative administration routes have been proposed and there is a growing interest and experience in sublingual therapy. The safety of alternative routes is nonetheless a real advantage, so long as it is not counterbalanced by a loss of clinical benefit. OBJECTIVE: We have compared the efficacy of the same biologically standardized grass pollen extract administered through the injective or the sublingual route, in a group of 20 patients followed for two pollen seasons. METHODS: Both therapies were administered for 12 months according to a double-blind (double-dummy) plan; at the end of the trial the cumulative dosage of the sublingual therapy was 2.4 times higher than that of the injective therapy. Data about skin reactivity, symptoms and drugs scores during the pollen season, as well as total specific IgG and specific IgG4, during and after the trial, were obtained. RESULTS: Our data show that sublingual and injective therapy are equally effective according to subjective clinical parameters, with a statistically highly significant reduction of symptoms and drugs (P = 0.002 for symptoms and drugs in SLIT-treated patients; P = 0.002 for symptoms and P = 0.0039 for drugs in patients given injections). On the other hand, objective parameters (total specific IgG, specific IgG4, skin reactivity) changed only in patients treated with active injective therapy, with P < 0.001, P < 0.001 and P = 0.021, respectively. CONCLUSIONS: The discrepancies observed could be interpreted as a consequence of different mechanisms of actin of the two therapies or to the lack of close relationships between the clinical and the objective parameters which were considered here.