Sequential determinations of Blomia tropicalis allergens in mattress and floor dust samples in a tropical city.

BACKGROUND: The mite species Blomia tropicalis is commonly found in tropical and subtropical regions, and it is an important source of allergen in the city of Cartagena, Columbia. AIM: The study was designed to determine seasonal allergen levels of B. tropicalis in homes of patients with asthma and mite allergy. METHODS: Dust samples from mattresses and floors in 20 homes were collected on a monthly basis for 1 year. Outdoor temperature, relative humidity, and rainfall were recorded. RAST inhibition was performed on extracts of dust samples. Allergen levels were compared with variations in climate. RESULTS: B. tropicalis allergens were detected in all mattress samples. More than 50% RAST inhibition was detected in 30% of mattress samples and in 4.3% of floor samples, reflecting a high concentration of allergen. Significant correlations were only found between allergen levels and absolute humidity. CONCLUSION: Levels of B. tropicalis allergen fluctuated minimally in Cartagena, Colombia.

IgE antibodies to four mite allergens in atopics and non-atopics living in Barbados - abstract

The prevalence of specific IgE (RAST) to Blomia tropicalis (Bt) was evaluated for 64 individuals from four families residing in Barbados, with self-reported atopic asthma (AA) and/or self-reported allergic rhinitis (AR) or individuals with no reported atopic disease (NA). The presence of specific IgE antibodies that reacted with components of Chortoglyphus arcuatus (Ca), Dermatophagoides pteronyssinus (Dp) and Euroglyphus maynei (Em) was also evaluated; components from Ca, Dp and Em were separated by SDS-PAGE, transferred to nitrocellulose membranes and screened with sera from the 22 AAs, 17 ARs and 25 NAs. Total serum IgE was significantly higher in individuals with self-reported AA (logIgE = 977 ng/ml) than in individuals reporting no AA (logIgE = 323 ng/ml). There was a significant difference between the number of AAs who were Bt-positive according to RAST (68 percent) and the number of individuals without AA(p=0.002). IgE antibodies to Ch and Em were significantly higher in individuals with AA than in those without AA (p = 0.001 and p = 0.005, respectively), and there was a weak correlation between IgE antibodies to Dp and self-reported AA (p=0.05). A significant pattern of conversion of response to certain bands within families was observed (AU)

Sensitivity to blomia tropicalis among allergic individuals in Barbados - abstract

The prevalence of specific IgE (RAST) to tropical house dust mite Blomia tropicalis (Bt) was studied in 126 related individuals with self-reported atopic asthma (AA) and/or self-reported allergic rhinitis (AR) and individuals with no reported atopic disease. RAST results were considered positive when a serum bound > 5 percent of the total counts (percent TCB) added; 17 (65.4 percent) AA were positive to Bt, 7 (29.2 percent) AR without AA were positive to Bt, and 16 (21.9 percent) individuals reporting no AA or AR were positive to Bt. Total serum IgE was significantly higher in individuals with self-reported AA (750 ng/ml) than in individuals reporting no AA (282 ng/ml; Student's t test, p = 0.02). There was no association between total serum IgE and self-reported AR. Additionally, total IgE was weakly correlated with RAST (Bt) for all individuals (r=0.349, p=0.001). Subjects with self-reported AA had a significantly higher mean percentage TCB (19 + 17) than individuals without self-reported AA (10 + 14; Student's test, p<0.05). This study suggests that sensitivity to Bt is common in individuals with atopic asthma living in Barbados (AU)

Cutaneous sensitivity to six mite species in asthmatic patients from five Latin American countries.

The prevalence of positive skin prick tests to the mite species Dermatophagoides pteronyssinus, D. farinae, Blomia tropicalis, Chortoglyphus arcuatus, Lepidoglyphus destructor and Aleuroglyphus ovatus was determined in 297 asthmatic adults and children living in seven cities of five Latin American countries. A standardized protocol and a common battery of extracts were used at each site. The mean wheal diameters were measured after 15 min, and those > or = 3 mm were considered positive. Sensitization to D. pteronyssinus varied from 60.7% in Cartagena to 91.2% in São Paulo; to D. farinae from 53.3% in Córdoba to 97.2% in Caracas; to A. ovatus from 26.6% in Bogotá to 71.2% in São Paulo; to B. tropicalis from 46.5% in Mexico City to 93.7% in São Paulo; to C. arcuatus from 33.3% in Mexico City to 75% in São Paulo; and to L. destructor from 30% in Mexico City to 76.2% in São Paulo. This study reported the results of skin test sensitivities in both children and adults. The studies from São Paulo and Córdoba were confined to children and thus could be compared; there was a significantly higher prevalence of cutaneous sensitivity to mite allergens in the children of São Paulo than in those of Córdoba (p < 0.001 for all mite species). Cutaneous sensitivity to mite allergens is very common in young and adult asthmatics in Latin America, in areas both at sea level and at high altitudes. Environmental control measures should be reinforced in the treatment of asthmatics in Latin America.

Mite allergy in the tropics: sensitization to six domestic mite species in Cartagena, Colombia.

Sensitization to the domestic mites Blomia tropicalis, Chortoglyphus arcuatus, Lepidoglyphus destructor and Aleuroglyphus ovatus was investigated in 77 subjects with clinical symptoms of asthma and/or allergic rhinitis and a positive skin prick test (wheal > or = 3 mm) to Dermatophagoides pteronyssinus and/or D. farinae. Seventy patients were skin test-positive to D. pteronyssinus and 73 to D. farinae. Serum samples from 29 nonallergic, skin test-negative individuals were used as negative controls. Specific IgE was determined by RAST and the results expressed as the % of the total counts bound (% TCB). A positive result (> or = 1% TCB) to D. farinae was detected in 89.6% of subjects, to B. tropicalis in 80.5%, to D. pteronyssinus in 75.3%, to C. arcuatus in 71.4%, to A. ovatus in 68.8% and to L. destructor in 59.7%. None of the controls had a positive RAST to any of the mite species. Different IgE binding patterns were observed among these subjects, suggesting sensitization to unique as well as common allergens in the different mite species. Sensitization to Pyroglyphidae (D. pteronyssinus and D. farinae) and non-Pyroglyphidae mites (B. tropicalis, C. arcuatus, L. destructor and A. ovatus) is common among allergic individuals in Cartagena. Extracts of these mites may be needed for a more accurate diagnosis and effective treatment of respiratory diseases due to mite allergy in tropical environments.

Reliability of sexual risk behavior interviews with psychiatric patients.

Test-retest interviews examining recent sexual activity were administered to 27 severely ill psychiatric patients after stabilization. Three reports were judged to be questionable. For the 16 sexually active patients among the remaining 24, high test-retest reliability was found for number of sexual partners, frequency of episodes, and proportions of episodes involving vaginal intercourse and use of condoms. The interviews did not exacerbate psychiatric symptoms.

Mite fauna, Der p I, Der f I and Blomia tropicalis allergen levels in a tropical environment.

Fifty dust samples were collected from the mattresses and bedroom floors of 25 subjects with allergic asthma in Cartagena, Colombia, in order to identify house dust mites and quantitate Der p I, Der f I and Blomia tropicalis allergens. The geometric mean of the total mite density per gram of dust was 418 (range, 40-2280). Twenty-two samples (44%) had more than 500 mites and four, less than 100. B. tropicalis and Dermatophagoides pteronyssinus were found in 96% and 90% of the samples, accounting for 40.1% and 35.7% of the total mites, respectively. Cheyletus malaccensis, Chortoglyphus arcuatus, Pyroglyphus africanus, Oribatids, Grallacheles bakeri, Tarsonemus spp., Suidasia spp., Dermatophagoides farinae and unidentified mites accounted for the rest. The geometric mean of the total mites/gram of dust in mattresses (563.9) was significantly higher than in floor dust (309.1), P < 0.01. Allergen concentrations and mite numbers were analysed by Spearman rank correlations: B. tropicalis mites vs B. tropicalis allergen, r = 0.54, P < 0.001; D. pteronyssinus mites vs Der p I, r = 0.52, P < 0.001. A negative correlation was obtained between B. tropicalis mites and Der p I. Allergens derived from B. tropicalis and other domestic mite species may play an important role in sensitization and allergic symptoms in Cartagena, Colombia.

Sensitization to Chortoglyphus arcuatus and Aleuroglyphus ovatus in Dermatophagoides spp. allergic individuals.

The prevalence of specific IgE to the storage mites Aleuroglyphus ovatus (Ao) and Chortoglyphus arcuatus (Ca) was studied in 77 individuals with allergic asthma and/or chronic allergic rhinitis. All these individuals had a positive skin test (weal > or = 3 mm) to extracts of Dermatophagoides pteronyssinus (Dp) and/or Dermatophagoides farinae (Df). Sera from 29 non-atopic individuals were used as controls. A RAST was considered positive when a serum bound > or = 1% of the total counts added. The prevalence of a positive RAST to Dp was 75.3%, and to at least one of the two storage mites (Ao and Ca), 76.6%. Among patients with a positive RAST to Dp, 79.3% and 75.8% were RAST positive to Ao and Ca, respectively. RAST inhibition studies with a pool of sera from 13 subjects with high RAST binding to all three mites showed significant crossreactivity between Ao and Ca and minimal to moderate crossreactivity between Dp and Ao and Ca. This study demonstrates that sensitization to Ao and Ca is common in individuals with respiratory allergies in Cartagena, Colombia and suggests that Ao, Ca and Dp have unique and common allergenic determinants.

HLA alleles in the population of Cartagena (Colombia).

It is known from historical records that the population of Cartagena (Colombia) is a mixture of caucasoids (Spaniards) and negroids (Africans) that is named mulattos. The present study was carried out to determine the distribution of HLA antigens in this population. A sample of 370 individuals was HLA serologically typed; 91 of them were typed for Complement alleles and 47 were DNA typed using PCR amplification and oligonucleotide probes for the HLA-DQA1 locus. The analysis of the allele and haplotype frequencies obtained, together with the genetic distances calculated with other populations, showed that most of the HLA genes of mulattos are from negroids and caucasoids. The Asian and Amerindian contribution is small, consistent with the historical and socioanthropological documentation. For example, A23, Aw34, Aw36 and Bw45, as well as DQA1*0101, DQA1*0301 and BfF have frequencies similar to that observed in negroids. In contrast, many significant differences were observed when comparing the antigen and allele frequencies of mulattos with that of Asians and Amerindians. Our results add evidence to the notion that the arrival of Spaniards in America 500 years ago established several racial mixtures. The HLA characterization of one of these, mulattos, will allow a better application of the HLA technology in the fields of basic research, organ transplantation and forensic medicine among this population.

HLA haplotype segregation in families with allergic asthma.

In order to evaluate genetic linkage between Allergic Asthma (AA) and the HLA system, we studied 20 families having AA affected sib pairs and 8 families with Intrinsic Asthma (IA) affected sib pairs. All AA patients had a strong IgE immune response to the mite D. farinae. Serological HLA typing (A, B, C, DR, and DQ antigens) was performed by the standard microcytotoxicity assay. Genetic analysis was made by means of the "Affected sib pairs" method. Out of the 20 affected sib pairs, 14 shared two HLA haplotypes, five shared one HLA haplotype and one was HLA-non-identical. These results differed significantly from the random ratio 1:2:1 for sharing, 2, 1 or 0 haplotypes (p less than 0.0001), and was very close to that expected for a recessive mode of inheritance. In contrast, among the IA sib pairs there was not an important distortion in the pattern of haplotypes segregation. However, a significant association between any of the HLA alleles and the two types of Asthma studied was not found. The results suggest the existence of an HLA-linked recessive gene controlling the IgE immune responsiveness to mite allergens and conferring susceptibility to AA.