Trastuzumab retreatment after relapse on adjuvant trastuzumab therapy for human epidermal growth factor receptor 2-positive breast cancer: final results of the Retreatment after HErceptin Adjuvant trial.

AIMS: Trastuzumab, in combination with chemotherapy, is the standard of care for patients with early and metastatic human epidermal growth factor receptor 2 (HER2)-positive breast cancer. The Retreatment after HErceptin Adjuvant trial assessed the efficacy and safety of trastuzumab plus a taxane as first-line treatment for patients with metastatic breast cancer (MBC) who had relapsed after adjuvant trastuzumab for HER2-positive early breast cancer. MATERIALS AND METHODS: In total, 43 patients with HER2-positive MBC who had received previous adjuvant trastuzumab for ≥10 months, with a relapse-free interval of ≥6 months after the last adjuvant trastuzumab dose, were recruited. Eligible patients (n = 41) were assigned to receive trastuzumab, either weekly or every 3 weeks, in combination with docetaxel or paclitaxel until disease progression. RESULTS: At the final analysis, with a median follow-up time of 40 months, a positive response was observed in 25/41 patients (61%; 95% confidence interval: 48.7-80.4%), stable disease in 7/41 (17.1%) and progressive disease in 6/41 (14.6%). Three patients had missing response assessments (one had no measurable lesions at baseline and two had no post-baseline tumour assessments). The median progression-free survival (PFS) was 8.0 months (95% confidence interval: 6-11 months) and the median overall survival was 25.0 months (16-33 months). No correlation was found between response rate, PFS or overall survival and the duration of adjuvant trastuzumab treatment, trastuzumab-free interval, relapse-free interval, hormone receptor status or type of pre-metastatic treatment. The most common adverse events (all grades) were alopecia (32%) and diarrhoea (32%). Six patients (14.6%) developed at least one serious adverse event. No congestive heart failure or any unexpected adverse events were reported. CONCLUSION: Trastuzumab, in combination with a taxane, is an effective and well-tolerated first-line treatment for MBC in patients who relapse after trastuzumab-based adjuvant therapy.

Hibiscus sabdariffa L. extracts inhibit the mutagenicity in microsuspension assay and the proliferation of HeLa cells.

Hibiscus sabdariffa L. is used as a refreshing beverage and as a traditional medicine. The objective of this study was to determine the in vitro effect of phenolic compounds present in aqueous, ethyl acetate, and chloroform extracts of H. sabdariffa against mutagenicity of 1-nitropyrene (1-NP), and also the antiproliferative effect of these extracts. Inhibition of cell proliferation and DNA fragmentation were tested on transformed human HeLa cells. The hot aqueous extract (HAE) contained 22.27 +/- 2.52 mg of protocatechuic acid (PCA) per gram of lyophilized dried extract, and was not statistically different from the cold aqueous or chloroform extracts; the ethyl acetate extract produced the least amount of PCA. The H. sabdariffa extracts inhibited mutagenicity of 1-NP in a dose-response manner. The inhibition rate on HeLa cells of HAE was also dose-dependent. The HAE did not induce DNA fragmentation. The results suggest that H. sabdariffa L. extracts have antimutagenic activity against 1-NP and decrease the proliferation of HeLa cells, probably due to phenolic acid composition.

Reactivity to recombinant house-dust-mite allergens in asthma and rhinitis in a tropical environment.

BACKGROUND: House-dust mites contain components that are allergenic in mite-sensitive patients, and a number of these have been produced in recombinant form. METHODS: In the present study, we evaluated by skin prick testing the positivity to native Der p 2 and recombinant Der p 2, Der p 5, and Der p 7 allergens of Dermatophagoides pteronyssinus in patients with rhinitis, asthma, or a combination of these diseases, who were positive to whole-mite extract. RESULTS: In all patients, the positivity to both native and recombinant Der p 2 was high. In patients with either rhinitis or asthma, the reactivity to Der p 5 and 7 was significantly lower than to Der p 2. However, in patients with combined disease, the positivity to the minor allergens was almost as high as that to Der p 2. CONCLUSIONS: These results raise the question of whether patients with combined allergic rhinitis and asthma, when compared to those with either of these diseases alone, are predisposed to react to a wider range of mite allergens, or, inversely, whether patients who respond to the minor allergens are more susceptible to suffering the combined disease.

[Housedust mite culture medium: an alternative source for the production of allergenic extracts]. / Medio de cultivo condicionado por el crecimiento de ácaros caseros: una fuente alternativa para la producción de extractos alergénicos.

House dust mites are the most important source of allergens in the tropical environment, and aqueous whole body extracts of these organisms have wide use in the diagnosis and treatment of allergic diseases. However, it has been reported that mite excretions have a high allergenic activity. Because of this, we have evaluated spent house-dust mite culture medium as an alternative source of allergens from these organisms. We demonstrated that the extraction of allergens from this material is more efficient in alkaline solutions such as ammonium bicarbonate, and when the extraction process is extended to 48 hours. When the purification process is complemented with dialysis and ammonium sulphate precipitation, the toxicity of the extract decreases and its allergenic activity increases. The electrophoretic pattern of proteins of the spent culture medium extract showed bands that bound specific IgE antibodies, but this extract may be deficient in one of the principle allergens of mites, Der pII. The extract stimulates immediate hypersensitivity skin reactions in house-dust allergic patients, and produces RAST inhibitions with their sera. The allergenic activity of this extract is comparable to that of the 1st. International Standard for house-dust mite extracts. These results demonstrate that spent house-dust mite culture medium is an appropriate source of allergens from these organisms, and because of its low commercial value, may be an economical alternative for the production of allergenic extracts.

Nonspecific changes in immunotherapy with house dust extract.

Despite the possible complications and inadequacies of the immunotherapy of allergic patients with house dust extracts (HDE), this is widely applied in Latin America and is commonly considered to be a cost-effective treatment for allergic diseases. Doubts about its efficacy and mechanism of action prompted us to evaluate the immunological changes that occurred in a group of 99 patients selected for their confirmed allergic sensitivity to house dust, and who showed significant clinical improvement after a minimum of 12 months of immunotherapy with HDE. The favorable clinical response of these patients was associated with some of the mechanisms reported for immunotherapy with pollen or venom allergens, such as increased levels of IgG or IgG4 "blocking" antibodies, and the increased affinity of these antibodies for house dust antigens, or diminished basophil sensitivity to HDE. However, the magnitude of these changes was relatively small, and their biological significance questionable. In contrast, particularly evident was a reduction in the cutaneous reactivity not only to the specific allergen, but also to the nonspecific mast cell degranulator codeine and to histamine. These results suggest that as yet unidentified "nonspecific" mechanisms might contribute to the effect of immunotherapy with extracts as heterogeneous and complex as HDE.

Effect of age and helminthic infection on IgE levels in slum children.

Helminthic infections can cause an IL-4-dependent polyclonal synthesis of IgE, which is the major cause of the elevated serum levels of this immunoglobulin in tropical populations. In the present study, we measured the IgE levels in the serum of children of different ages in slum areas of Caracas, Venezuela, where intestinal helminths are endemic. As would be expected, in children over 5 years of age, the IgE levels were highly elevated, and in addition, the cord blood serum levels were higher than those reported for populations where parasitic infections are uncommon. However, the IgE levels measured in the sera of children under 5 years of age were relatively low, and within the generally accepted normal ranges. This was surprising because the latter children were infected by parasites and had high IgG antibody levels against helminths. We found, however, that whereas older children had detectable IL-4 levels in their sera, the younger children did not. These results suggest that, despite infection of these slum children by common intestinal helminths, a polyclonal stimulation of IgE synthesis did not occur, possibly due to a lack of IL-4 production by an immature immune system.

Allergic reactivity of children of different socioeconomic levels in tropical populations.

Widely variable prevalences of allergic diseases have been reported in tropical populations, and this has been suggested to be due to effects of the nonspecific polyclonal stimulation of IgE synthesis caused by the helminthic infections that are endemic in these areas. Since 1980, we have been evaluating the allergic reactivity of different socioeconomic sectors of the population of tropical Venezuela (lat. 2-12 degrees N), and in the present study analyze the overall results obtained in the laboratory evaluation of children (5-15 years of age) belonging to these groups. Children of medium-high socioeconomic level (M-HSEL), who experience occasional helminthic infections, have moderately high total serum IgE levels, and have elevated skin test positivities and specific IgE levels against environmental allergens. Persons of low socioeconomic level, in the urban, and particularly rural situation experience frequent helminthic infection, and have highly elevated total serum IgE levels. In contrast to the M-HSEL, the majority of these children have detectable specific IgE antibody against a variety of inhalant allergens, but relatively few have high levels, and their skin test positivity is also low. In these frequently parasitized persons, evidence of saturation of mast cell Fc epsilon receptors was found by tests of passive sensitization. We propose, therefore, that helminthic parasites have a biphasic effect on allergic reactivity; occasional infections are stimulatory, via their nonspecific potentiation of IgE synthesis against environmental allergens, and frequent infections are suppressive due to the widely polyclonal stimulation that they cause, resulting in both diminished specific antibody production against any given allergen and mast cell Fc epsilon receptor saturation.

Ascaris y alergía / Ascaris and alergy

Existen dos situaciones en las cuales es importante medir los niveles séricos de la IgE en las enfermedades alérgicas y en las parasitosis helmínticas. En este estudio fueron modificados ciertos aspectos en el procesamiento convencional. Primero se sometió a prueba el uso de discos de nitrocelulosa a los cuales se fijan proteínas y otros antígenos, sin la necesidad de una activación previa. Por otro lado, se utilizó un sistema ELISA (prueba inmunoenzimática en lugar de los marcadores radiactivos. Se establecieron comparaciones entre sujetos alérgicos y no alérgicos, y los resultados mostraron que las características de las reacciones pulmonares inducidas fueron del tipo alérgico, siendo reversibles por la inhalación de broncodilatadores. Hubo 4 pacientes asmáticos, en los cuales la inhalación del extracto no produjo ninguna reacción pulmonar, dichos resultados sugieren que las infecciones por helmintos intestinales, particularmente ascaris, no deben ser ignoradas como posibles agentes etiológicos del asma en el ambiente tropical

Seroprevalence of Toxocara canis infection in tropical Venezuela.

An enzyme-linked immunosorbent assay (ELISA) was used to determine the seroprevalence of Toxocara canis infection in different socio-economic groups of the tropical population of Venezuela. The lack of definitive independent diagnostic criteria for toxocariasis required the establishment of operational upper limits of normality for Toxocara ELISA values, based upon their log-normalized distribution in a presumptive "non-toxocariasis" sub-population. Only 1.8% of urban subjects of medium-high socio-economic level were considered to be clearly positive in Toxocara ELISA, compared to 20.0% of urban slum dwellers, 25.6% rural subsistence farmers and 34.9% Amazon Indians. As the test was performed using excretory-secretory antigen, and under conditions of competitive inhibition by soluble extracts of non-homologous parasites, co-infection by common intestinal helminths, protozoa or other organisms did not give rise to false positive results. However, strong cross-reactivity with Onchocerca volvulus may have influenced the prevalence figure obtained for the Amazon Indians. These results indicate that T. canis is yet another parasite that is widely distributed in economically underprivileged tropical populations.

Infestación por Ascaris: una posible explicación para los altos niveles de IgG anti-A observados en la población venezolana / Ascaris infestation: a possible explanation for the high levels of IgG anti-A found in Venezuela populations

Hemos investigado los niveles de IgG anti-A y los de IgG anti-Ascaris en grupos de nivel socioeconómico alto (NSEA) con un bajo grado de infestación por Ascaris (5,6%), de nivel socioeconómico bajo (NSEB) con un 47,6% por ciento de infestación y de indígenas del Amazonas con un nivel de infestación del 67,5 por ciento. Los títulos de IgG anti-A y anti-B se determinaron por hemaglutinación simple y por la técnica indirecta de Coombs, y los de IgG anti-Ascaris (en su forma adulta) por una técnica inmunoenzimática. Los títulos de IgG anti-A obtenidos por la prueba de Coombs, fueron significativamente mayores en el grupo indígena (media geométrica 1833) y en el de NSEB (659) en relación al grupo de NSEA (225). Aunque hubo una asociación positiva entre la frecuencia de infestación por Ascaris y los niveles de IgG anti-A, al comparar individualmente los títulos de IgG anti-A con los de IgG anti-Ascaris no se obtuvo correlación. Sin embargo, estos resultados no descartan la posibilidad de que componentes de otros estadios del parásito presenten reactividad cruzada con el antígeno A

Allergic reactivity and socio-economic level in a tropical environment.

As some factors associated with the tropical environment can modify the expression of atopic disease, various indicators of allergic reactivity were compared between allergic and non-allergic subjects of different socio-economic level in Caracas, Venezuela (Lat. 10 degrees N). The socio-economic levels considered were high (HSEL), medium-high (MSEL) or low (LSEL). As generally found in temperature climates, in the HSEL the total serum IgE levels of allergic patients were significantly greater than those of non-allergic individuals (geometric means of 274 vs 126 IU/ml, respectively), as were also the specific serum IgE antibody levels (55.6 vs 23.8% positive, respectively, for house dust). These results correlated closely with the skin-test reactivity of these subjects (60.3 vs 17.5% positive for house dust). In this group, the degree of intestinal helminthic infection was low (5.6% positive for Ascaris). In contrast, for the MSEL where the degree of parasitic infection was higher (13.0%), the total serum IgE levels were elevated in both allergic and non-allergic subjects (602 vs 363 IU/ml). Similarly, positivity for specific IgE antibody was high, and comparable between allergics and non-allergics of this group (61.5 vs 54.2%), as was also the case for skin-test reactivity (71.9 vs 60.4%). In the LSEL, parasitic infection was prevalent (47.6%), and the total serum IgE levels were markedly elevated, with little difference occurring between allergic and non-allergic individuals (2269 vs 1981 IU/ml). The positivity for specific IgE antibody was high, and effectively independent of the allergic state (75.6 vs 53.7%), but in contrast the skin test reactivity was relatively low (22.0 vs 9.8%).(ABSTRACT TRUNCATED AT 250 WORDS)

Measurement of anti-Ascaris IgE antibody levels in tropical allergic patients, using modified ELISA.

The two most common situations in which the determination of serum immunoglobulin E (IgE) levels is of interest are allergic disease and helminthic infection. This is of particular importance in the tropical environment, as helminthiasis possibly influences the expression of allergic reactivity. Because of the low absolute serum levels of IgE, solid-phase radioimmunoassay (RIA) is conventionally used for its measurement. The radioactive and toxic volatile reagents required restricted application of such assays in the tropical situation. We evaluated a nitrocellulose-based, avidin biotin-amplified enzyme-linked immunosorbent assay (ELISA) for IgE, in which monoclonal anti-IgE antibodies were employed. Excellent correlations were obtained between ELISA and RIA for both total and allergen-specific IgE measurement. The ELISA was then applied to determine the levels of anti-Ascaris antibodies in selected allergic patients, in whom no cutaneous immediate hypersensitivity reactions were demonstrated against common environmental allergens such as house dust, but who had positive skin reactions to Ascaris extract. When compared with non-allergic subjects who had equivalent cutaneous reactivity, no significant differences were found in total IgE levels, house-dust specific IgE levels or non-reaginic anti-Ascaris antibody levels. However, higher levels of IgE antibody against the parasite were detected in the allergic subjects. This observation raises the question of the possible role of Ascaris infection in the stimulation of allergic reactions in such patients. We describe an immunoenzymatic assay for total and specific IgE antibody that is better adapted to the tropical situation than the commonly used radioimmunoassays.(ABSTRACT TRUNCATED AT 250 WORDS)

An unusual case of hyper-production of IgE, treated by plasmapheresis.

A 15-year-old boy with severe inflammatory skin lesions from an early age was found to have extremely elevated serum IgE levels (up to 376.000 IU/ml). His skin showed positive direct immunofluorescence for IgE and he had peripheral and bone marrow eosinophilia. No evidence for atopic disease was found, but he suffered intestinal helminthic infection of moderate intensity. He showed a somewhat depressed cell mediated immune response but a normal polymorphonuclear function. Various treatments that included anti-inflammatory, anti-allergic, anti-parasitic, anti-mycotic and PUVA therapy did not significantly improve his condition A therapeutic test using plasmapheresis produced marked, though short-lived clinical improvement. We believe that this case might result from the superimposition of the stimulatory effects of intestinal helminthiasis on a background of intrinsic hyper-production of IgE.

Interrelationships between immediate, intermediate, and delayed cutaneous reactions and their in vitro correlates.

The mutual correlations between immediate, intermediate, and delayed cutaneous reactions, IgE, IgG, or combined IgG, A, and M antibody levels, and antigen- or mitogen-induced lymphocyte transformation were evaluated in a mixed group of allergic or non-allergic individuals. As might be expected, immediate and delayed reactions correlated significantly with IgE antibody levels and lymphocyte transformation, respectively. Intermediate time-course reactions did not correlate with IgG or IgG, A, and M antibody levels, but did so with immediate reactions, thus suggesting their "late phase" nature. Of particular interest was the finding of correlations that do not conform to the classical concept of the mechanisms involved in the generation of the different cutaneous reactions. Significant correlations were found between immediate or intermediate reactions and antigen-induced lymphocyte transformation, and between immediate and delayed reactions. These results are discussed in relation to recent suggestions that factors released from sensitized T cells can mediate early time-course reactions, and that such reactions may contribute to the manifestation of delayed-type hypersensitivity.

Incidence of atopic disease in a tropical environment: partial independence from intestinal helminthiasis.

The reported incidence of atopic disease in the tropical environment, albeit somewhat controversial, has often been very low. This has been postulated to be due to an inhibitory influence of intestinal helminthiasis, although the predominantly rural nature of the populations studied might also be an important factor to consider. We evaluated two tropical groups in Venezuela that were basically comparable, both being highly parasitized but one of which was urban and the other rural. The apparent incidence of allergic conditions in the urban group was, in fact, comparable to that in temperate countries, whereas that of the rural subjects was markedly lower. A similar difference was found in skin test positivity to common inhalant allergens, although reactivity to Ascaris extract was comparably high between the two groups, and total serum IgE and eosinophil levels were uniformly elevated. Our results suggest that the incidence of atopic disease in the topical environment may depend not only on the intensity of helminthiasis suffered but also on factors related to the urban-rural situation.