ABSTRACT
Background: Banana allergy is on the rise in tropical regions. Advances in genomics and candidate gene identification have increased interest in genetic factors in food allergies. However, the genetic basis of IgE-mediated banana allergy is underexplored. Objective: To characterize HLA variants and their association with IgE-mediated banana allergy. Methods: This cross-sectional study recruited banana-allergic adults, confirmed by allergology tests, with non-allergic individuals as controls. Genomic DNA extraction and sequencing BAM files for HLA typing were conducted. Allele frequency was calculated using the direct counting method, and odds ratio (OR) with 95 % confidence interval (CI) were determined. Fisher's exact or chi-square tests were used to assess associations with Bonferroni's correction for multiple tests. The allele frequency of the Thai population from The Allele Frequency Net Database was used to compute the allele enrichment ratio (ER). Results: A total of 59 cases and 64 controls were recruited. HLA genotyping indicated potential associations of HLA-B*15:25 (OR 11.872; p-value 0.027), HLA-C*04:03 (OR 7.636; p-value 0.033), and HLA-DQB1*06:09 (OR 11.558; p-value 0.039) with banana allergy. However, after Bonferroni correction, none of these associations reached statistical significance. Comparing allele frequency with the general population from The Allele Frequency Net Database, our ER analysis revealed a higher prevalence in the banana allergy group for B*15:25 (ER 1.849), C*04:03 (ER 1.332), and DQB1*06:09 (ER 6.602) alleles. Conclusions: This study provides initial genetic insights into banana allergy, suggesting potential links with specific HLA alleles. Despite 12 initially identifying alleles, none were statistically significant after multiple testing correction. Larger studies are needed to detect possible significant correlations.
ABSTRACT
BACKGROUND: Perioperative anaphylaxis is a severe immediate hypersensitivity reaction to drugs administered in immediate temporal association to surgical procedures. The European Academy of Allergy and Clinical Immunology recommends allergologic tests be performed within the golden period of between 1 and 4 months after the date of the event to avoid false negatives. Nonetheless, many obstacles prevent patients from receiving diagnostic tests within the recommended time frame. CASE PRESENTATION: A 39-year-old male with congenital glaucoma had a history of multiple episodes of perioperative anaphylaxis since the age of 1 year including generalized urticaria, bronchospasm, cyanosis, and hypotension. Because the sequence of events was unclear due to incomplete documentation of operations and the destruction of medical records, the allergists tested different perioperative drugs on the patient. Although the first test results were all negative, repeated tests at 6 weeks were positive for morphine and ketamine. We identified more than one causative drug at the second round of skin tests. Using recommended skin test concentrations, negative skin tests in 5 control subjects could support the validity of the second test. The patient underwent sinus surgery in the next 3 months after the second skin test using propofol, midazolam, sevoflurane, chlorhexidine, and cefazolin without any anaphylactic reactions. CONCLUSIONS: Repeated skin tests after negative results of the first tests may identify the causative drugs, thus providing optimal patient safety, and should be considered under the physician's discretion together with consideration of the severity of the allergic symptoms, time interval from last reactions, and the patient's consent.
ABSTRACT
BACKGROUND: Oral mite anaphylaxis (OMA) is a condition characterized by severe allergic reactions after ingesting food containing dust mite-contaminated flour. Physical exertion is recognized as a common trigger factor inducing anaphylaxis. The association of OMA with exercise-induced anaphylaxis has rarely been reported. CASE PRESENTATION: We report a 29-year-old Thai woman who had dust mite ingestion-associated, exercise-induced anaphylaxis who tolerated the same bag of contaminated flour without exercise. A sample of contaminated cooking flour was examined under a light microscope. Living mites, Dermatophagoides farinae, were detected by a medical entomologist based on the morphology. We performed skin test to both mite-contaminated and newly opened Gogi® cooking flour, common aeroallergens, food allergens, and all other ingredients in the fried coconut rice cake 5 weeks after the anaphylactic episode. Specific IgE tests, using ImmunoCAP were also performed. CONCLUSIONS: Dust mite ingestion-associated, exercise-induced anaphylaxis may be misdiagnosed as wheat-dependent exercise-induced anaphylaxis and should be suspected in patients with anaphylaxis linked to food intake and exercise, but who have no apparent evidence to the index food ingredients on allergy workup.
ABSTRACT
The early detection of drug-resistant tuberculosis (TB) strains is of utmost importance for patient management and effective TB control programs. This study aimed to demonstrate the performance of direct drug susceptibility testing (DST) performed in our laboratory in the past 11 years. The direct DST was performed on Middlebrook 7H10 medium using isoniazid (INH) and rifampicin (RIF), and the results were compared with those obtained from indirect DST (gold standard). The direct DST was performed with 15,598 smear-positive sputum samples, of which 11,284 (72%) yielded reportable results. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated and revealed 89%, 99%, 95%, and 99%, respectively, for RIF and 90%, 98%, 93%, and 97%, respectively, for INH. Direct DST results could be reported within 1 month after sample processing. This method was also shown to be suitable for use in resource-limited countries, particularly in settings with high numbers of TB cases.
