Human leucocyte antigen-adverse drug reaction associations: from a perspective of ethnicity

Case Report: A successful case of toxic epidermal necrolysis treated with plasmapheresis therapy

Toxic epidermal necrosis (TEN) is rare and can be life-threatening for patients. Appropriate management of TEN patients could give optimal results and prevent complications. One treatment modality for TEN is plasmapheresis, which is rarely available in most cases with severe TEN. Here we reported a successful treatment of severe TEN with plasmapheresis. A 40-year-old woman under tuberculosis therapy complained of shortness of breath that began four days prior to hospital admission and worsened ever since. The patient's skin was peeling with red spots and rashes all over the body for a week. During the examination, the patient was compos mentis, and the SCORTEN score was 2 with 12.1% risk of mortality rate. Dermatological examination of the face, trunk and extremities found extensive erosions, loose bullae filled with clear fluid, brown crusts, and generalized distribution with more than 30% epidermolysis. The patient was diagnosed with toxic epidermal necrolysis caused by antituberculosis therapy. We treated the patient by discontinuing the suspected drugs and administering the corticosteroids, but no improvement was observed. The patient underwent two cycle plasmaphereses with 5% albumin, resulting in 1.2 liter of plasma exchange. Re-epithelialization was observed after three days, and the patient was discharged on day 8. This case-report highlights the important role of plasmapheresis in treating the TEN patients. However, a study with larger sample sizes is warranted to validate the efficacy of plasmapheresis in TEN.

African Global Representation in Biomedical Sciences

African populations are diverse in their ethnicity, language, culture, and genetics. Although plagued by high disease burdens, until recently the continent has largely been excluded from biomedical studies. Along with limitations in research and clinical infrastructure, human capacity, and funding, this omission has resulted in an underrepresentation of African data and disadvantaged African scientists. This review interrogates the relative abundance of biomedical data from Africa, primarily in genomics and other omics. The visibility of African science through publications is also discussed. A challenge encountered in this review is the relative lack of annotation of data on their geographical or population origin, with African countries represented as a single group. In addition to the abovementioned limitations,the global representation of African data may also be attributed to the hesitation to deposit data in public repositories. Whatever the reason, the disparity should be addressed, as African data have enormous value for scientists in Africa and globally.

A snapshot of human leukocyte antigen (HLA) diversity using data from the Allele Frequency Net Database

The extensive allelic variability observed in several genes related to the immune response and its significance in different areas including transplantation, disease association studies, diversity in human populations, among many others, has led the scientific community to analyse these variants among individuals. Serving as an electronic data warehouse, the Allele Frequency Net Database (AFND, http://www.allelefrequencies.net) contains data on the frequency of immune related genes and their corresponding alleles from more than 1700 worldwide population samples covering more than ten million unrelated individuals. The collection of population data sets available in AFND encompasses different polymorphic regions including the highly-polymorphic human leukocyte antigen (HLA) system for which more than 1200 populations are available. In this article, we provide an insight of the high diversity found in the HLA region by examining population data sets stored in AFND, as well as a description of the available data sets for further analyses.

Allele frequency net database (AFND) 2020 update: gold-standard data classification, open access genotype data and new query tools

The Allele Frequency Net Database (AFND, www.allelefrequencies.net) provides the scientific community with a freely available repository for the storage of frequency data (alleles, genes, haplotypes and genotypes) related to human leukocyte antigens (HLA), killer-cell immunoglobulin-like receptors (KIR), major histocompatibility complex Class I chain related genes (MIC) and a number of cytokine gene polymorphisms in worldwide populations. In the last five years, AFND has become more popular in terms of clinical and scientific usage, with a recent increase in genotyping data as a necessary component of Short Population Report article submissions to another scientific journal. In addition, we have developed a user-friendly desktop application for HLA and KIR genotype/population data submissions. We have also focused on classification of existing and new data into ‘gold–silver–bronze’ criteria, allowing users to filter and query depending on their needs. Moreover, we have also continued to expand other features, for example focussed on HLA associations with adverse drug reactions. At present, AFND contains >1600 populations from >10 million healthy individuals, making AFND a valuable resource for the analysis of some of the most polymorphic regions in the human genome.

HLA-DRB1*07:01 and lapatinib-induced hepatotoxicity: a systematic review and meta-analysis

Associations between HLA-DRB1*07:01 and lapatinib-induced hepatotoxicity have been reported. To consolidate the results from all available reports in scientific databases, systematic review and meta-analysis techniques were used to quantify these associations. Studies investigating associations between HLA-DRB1*07:01 and lapatinib-induced hepatotoxicity were systematically searched in PubMed, Human Genome Epidemiology Network, and the Cochrane Library. Primary outcomes were the associations between HLA-DRB1*07:01 and lapatinib-induced hepatotoxicity. Overall odds ratios (ORs) with the corresponding 95%CIs were calculated using a random-effect model to determine the associations between HLA-DRB1*07:01 and lapatinib-induced hepatotoxicity. A clear association between HLA-DRB1*07:01 and lapatinib-induced hepatotoxicity was identified in our analyses. The summary OR was 6.23 (95%CI = 4.11-9.45). Similar associations were also found in the subgroup analyses by lapatinib treatment regimens. ORs were 10.04 (95%CI = 6.15-16.39), 8.65 (95%CI = 4.52-16.58), and 3.88 (95%CI = 2.20-6.82) in the lapatinib group, lapatinib + trastuzumab group, and lapatinib + chemotherapy or lapatinib + trastuzumab + chemotherapy group, respectively. Since HLA-DRB1*07:01 is associated with lapatinib-induced hepatotoxicity, genetic screening of HLA-DRB1*07:01 in breast cancer patients prior to lapatinib therapy is warranted for patient safety. In addition, further studies should define the risk of HLA-DRB1*07:01 and lapatinib-induced hepatotoxicity in specific ethnicities.

Allele Frequency Net Database

The allele frequency net database (AFND, http://www.allelefrequencies.net ) is an online web-based repository that contains information on the frequencies of immune-related genes and their corresponding alleles in worldwide human populations. At present, the system contains data from 1505 populations in more than ten million individuals on the frequency of genes from different polymorphic regions including data for the human leukocyte antigens (HLA) system. This resource has been widely used in a variety of contexts such as histocompatibility, immunology, epidemiology, pharmacogenetics, and population genetics, among many others. In this chapter, we present some of the more commonly used searching mechanisms and some of the most recent developments included in AFND.

Sulfasalazine-Induced Agranulocytosis Is Associated With the Human Leukocyte Antigen Locus

Agranulocytosis is a serious, although rare, adverse reaction to sulfasalazine, which is used to treat inflammatory joint and bowel disease. We performed a genome-wide association study comprising 9,380,034 polymorphisms and 180 HLA alleles in 36 cases of sulfasalazine-induced agranulocytosis and 5,170 population controls. Sulfasalazine-induced agranulocytosis was significantly associated with the HLA region on chromosome 6. The top hit (rs9266634) was located close to HLA-B, odds ratio (OR) 5.36 (95% confidence interval (CI) (2.97, 9.69) P = 2.55 × 10^-8 ). We HLA-sequenced a second cohort consisting of 40 cases and 142 treated controls, and confirmed significant associations with HLA-B*08:01, OR = 2.25 (95% CI (1.02, 4.97) P = 0.0439), in particular the HLA-B*08:01 haplotype HLA-DQB1*02:01-DRB1*03:01-B*08:01-C*07:01, OR = 3.79 (95% CI (1.63, 8.80) P = 0.0019), and with HLA-A*31:01, OR = 4.81 (95% CI (1.52, 15.26) P = 0.0077). The number needed to test for HLA-B*08:01 and HLA-A*31:01 to avoid one case was estimated to be 1,500. We suggest that intensified monitoring or alternative treatment should be considered for known carriers of HLA-B*08:01 or HLA-A*31:01.

Donor Selection for Allogenic Hemopoietic Stem Cell Transplantation: Clinical and Ethical Considerations

Allogenic hematopoietic progenitor cell transplantation (allo-HSCT) is an established treatment for many diseases. Stem cells may be obtained from different sources: mobilized peripheral blood stem cells, bone marrow, and umbilical cord blood. The progress in transplantation procedures, the establishment of experienced transplant centres, and the creation of unrelated adult donor registries and cord blood banks gave those without an human leucocyte antigen- (HLA-) identical sibling donor the opportunity to find a donor and cord blood units worldwide. HSCT imposes operative cautions so that the entire donation/transplantation procedure is safe for both donors and recipients; it carries with it significant clinical, moral, and ethical concerns, mostly when donors are minors. The following points have been stressed: the donation should be excluded when excessive risks for the donor are reasonable, donors must receive an accurate information regarding eventual adverse events and health burden for the donors themselves, a valid consent is required, and the recipient's risks must be outweighed by the expected benefits. The issue of conflict of interest, when the same physician has the responsibility for both donor selection and recipient care, is highlighted as well as the need of an adequate insurance protection for all the parties involved.