Vaginal bacterial load in the second trimester is associated with early preterm birth recurrence: a nested case-control study.

OBJECTIVE: To assess the association between vaginal microbiome (VMB) composition and recurrent early spontaneous preterm birth (sPTB)/preterm prelabour rupture of membranes (PPROM). DESIGN: Nested case-control study. SETTING: UK tertiary referral hospital. SAMPLE: High-risk women with previous sPTB/PPROM <34+0 weeks' gestation who had a recurrence (n = 22) or delivered at ≥37+0 weeks without PPROM (n = 87). METHODS: Vaginal swabs collected between 15 and 22 weeks' gestation were analysed by 16S rRNA gene sequencing and 16S quantitative PCR. MAIN OUTCOME MEASURE: Recurrent early sPTB/PPROM. RESULTS: Of the 109 high-risk women, 28 had anaerobic vaginal dysbiosis, with the remainder dominated by lactobacilli (Lactobacillus iners 36/109, Lactobacillus crispatus 23/109, or other 22/109). VMB type and diversity were not associated with recurrence. Women with a recurrence, compared to those without, had a higher median vaginal bacterial load (8.64 versus 7.89 log10 cells/mcl, adjusted odds ratio [aOR] 1.90, 95% CI 1.01-3.56, P = 0.047) and estimated Lactobacillus concentration (8.59 versus 7.48 log10 cells/mcl, aOR 2.35, (95% CI 1.20-4.61, P = 0.013). A higher recurrence risk was associated with higher median bacterial loads for each VMB type after stratification, although statistical significance was reached only for L. iners domination (aOR 3.44, 95% CI 1.06-11.15, P = 0.040). Women with anaerobic dysbiosis or L. iners domination had a higher median vaginal bacterial load than women with a VMB dominated by L. crispatus or other lactobacilli (8.54, 7.96, 7.63, and 7.53 log10 cells/mcl, respectively). CONCLUSIONS: Vaginal bacterial load is associated with early sPTB/PPROM recurrence. Domination by lactobacilli other than L. iners may protect women from developing high bacterial loads. Future PTB studies should quantify vaginal bacteria and yeasts. TWEETABLE ABSTRACT: Increased vaginal bacterial load in the second trimester may be associated with recurrent early spontaneous preterm birth.

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

Whilst immune-mediated adverse drug reactions (ADRs) are rare, they are potentially life-threatening and present a major problem for clinicians. The underlying mechanisms that cause ADRs are not fully understood although genomewide association studies (GWAS) and case-control investigations have associated human leucocyte antigen (HLA) alleles as risk factors. There is evidence that a patient's ethnic background can have an impact on their risk of developing an ADR. This review summarizes the evidence related to HLA alleles and ADRs with particular focus on patient ethnicity. Our analysis indicated that many of the alleles which have been associated with ADRs are found at higher frequencies in Asian populations. The data also showed that many of the alleles that are reported to be statistically significantly associated with ADRs are in linkage disequilibrium with each other and that they form haplotypes specific to certain ethnicities indicating at least some of the allele associations may not be causal.

Low dose aspirin and pregnancy: how important is aspirin resistance?

UNLABELLED: Antiplatelet agents are pivotal for prevention of coronary artery disease and cerebrovascular disease worldwide. Individual patient data meta-analysis indicates that low-dose aspirin causes a 10% risk reduction in pre-eclampsia for women at high individual risk. However, in the last 15 years it has emerged that a significant proportion of aspirin-treated individuals exhibit suboptimal platelet response, determined biochemically and clinically, termed 'aspirin non-responsiveness', 'aspirin resistance' and 'aspirin treatment failure'. More recently, investigation of aspirin responsiveness has begun in pregnant women. This review explores the history and clinical relevance of 'aspirin resistance' applied to high-risk obstetric populations. TWEETABLE ABSTRACT: Is 'aspirin resistance' clinically relevant in high-risk obstetrics?

HLA-DQ allele-restricted activation of nitroso sulfamethoxazole-specific CD4-positive T lymphocytes from patients with cystic fibrosis.

BACKGROUND: For certain HLA allele-associated drug hypersensitivity reactions, the parent drug has been shown to associate directly with the risk allele. In other forms of hypersensitivity, HLA risk alleles have not been identified and T cells are activated in an allele unrestricted manner. Chemically reactive drug metabolites bind to multiple proteins; thus, it is assumed that the derived peptide antigens interact with a number of HLA molecules to activate T cells; however, HLA restriction of the drug metabolite-specific T-cell response has not been studied. OBJECTIVE: To utilize T cells from sulfamethoxazole (SMX) hypersensitive patients with cystic fibrosis to examine the HLA molecules that interact with nitroso SMX (SMX-NO)-derived antigens. METHODS: T-cell clones were generated from 4 hypersensitive patients. Drug-specific proliferative responses and cytokine secretion were measured. Anti-human class I and class II antibodies were used to analyse HLA restriction. Antigen-presenting cells expressing different HLA molecules were used to determine the alleles involved in the presentation of SMX-NO-derived antigens to T cells. RESULTS: A total of 976 clones were tested for SMX-NO reactivity. Thirty-nine CD4+ clones were activated with SMX-NO and found to proliferate and secrete cytokines. The SMX-NO-specific response was blocked with an antibody against HLA-DQ. SMX-NO-specific responses were detected with antigen-presenting cells expressing HLA-DQB1*05:01 (patient 1) and HLA-DQB1*02:01 (patient 2), but not other HLA-DQB1 alleles. CONCLUSION AND CLINICAL RELEVANCE: HLA-DQ plays an important role in the activation of SMX-NO-specific CD4+ T cells. Detection of HLA-DQ allele-restricted responses suggests that T cells are activated by a limited repertoire of SMX-NO-modified peptides.

A microRNA-based prediction algorithm for diagnosis of non-small lung cell carcinoma in minimal biopsy material.

BACKGROUND: Diagnosis is jeopardised when limited biopsy material is available or histological quality compromised. Here we developed and validated a prediction algorithm based on microRNA (miRNA) expression that can assist clinical diagnosis of lung cancer in minimal biopsy material to improve clinical management. METHODS: Discovery utilised Taqman Low Density Arrays (754 miRNAs) in 20 non-small cell lung cancer (NSCLC) tumour/normal pairs. In an independent set of 40 NSCLC patients, 28 miRNA targets were validated using qRT-PCR. A prediction algorithm based on eight miRNA targets was validated blindly in a third independent set of 47 NSCLC patients. The panel was also tested in formalin-fixed paraffin-embedded (FFPE) specimens from 20 NSCLC patients. The genomic methylation status of highly deregulated miRNAs was investigated by pyrosequencing. RESULTS: In the final, frozen validation set the panel had very high sensitivity (97.5%), specificity (96.3%) and ROC-AUC (0.99, P=10(-15)). The panel provided 100% sensitivity and 95% specificity in FFPE tissue (ROC-AUC=0.97 (P=10(-6))). DNA methylation abnormalities contribute little to the deregulation of the miRNAs tested. CONCLUSION: The developed prediction algorithm is a valuable potential biomarker for assisting lung cancer diagnosis in minimal biopsy material. A prospective validation is required to measure the enhancement of diagnostic accuracy of our current clinical practice.

Investigation of inter-individual variability of the one-carbon folate pathway: a bioinformatic and genetic review.

Genetic polymorphisms in the one-carbon folate pathway have been widely studied in association with a number of conditions. Most of the research has focused on the 677C>T polymorphism in the coding region of the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene. However, there are a total of 25 genes in this pathway coding for enzymes, transporters and receptors, which can be investigated using 267 tagging single nucleotide polymorphisms (SNPs); using SNP database (dbSNP), 38 non-synonymous SNPs with a minor allele frequency of >5% are present in these genes. Most of these variants have not been investigated in relation to disease or drug response phenotypes. In addition, their functional consequences are largely unknown. Prediction of the functional effect using six publicly available programs (PolyPhen, SIFT BLink, PMut, SNPs3D, I-Mutant2.0 and LS-SNP) was limited to functionally well-characterized SNPs such as MTHFR c.677C>T and c.1298A>C ranking low. Epigenetic modifications may also be important with some of these genes. In summary, to date, investigation of the one-carbon folate pathway genes has been limited. Future studies should aim for a more comprehensive assessment of this pathway, while further research is also required in determining the functional effects of these genetic variants.

Genetics of immune-mediated adverse drug reactions: a comprehensive and clinical review.

Adverse drug reactions (ADRs) are common and are a major problem in drug therapy. Patients experience unnecessary morbidity and mortality whilst many effective drugs are withdrawn because of ADRs in a minority of patients. Recent studies have demonstrated significant associations between human leukocyte antigens (HLA) and predisposition to ADRs such as drug-induced skin injury (DISI) and drug-induced liver injury (DILI). HLA-B*58:01 has been significantly associated with allopurinol-induced hypersensitivity. Associations between HLA and carbamazepine hypersensitivity reactions demonstrate both ethnicity and phenotype specificity; with HLA-B*15:02 associated with Stevens-Johnson syndrome and toxic epidermal necrolysis in South East Asian patients only whilst HLA-A*31:01 is associated with all phenotypes of hypersensitivity in multiple ethnicities. Studies of ximelagatran, an oral direct thrombin inhibitor withdrawn because of hepatotoxicity, found associations between HLA-DRB1*07:01 and HLA-DQA1*02:01 and ximelagatran DILI. Interestingly, HLA-B*57:01 is associated with both abacavir DISI and flucloxacillin DILI but the reasons for the different phenotype of ADR remains unknown. Pharmacogenetic screening for HLA-B*57:01 prior to abacavir therapy has significantly reduced the incidence of abacavir hypersensitivity syndrome in clinical practice. No other HLA associations have been translated into clinical practice because of multiple reasons including failure to replicate, inadequate sample sizes, and our lack of understanding of pathophysiology of ADRs. Here, we review genetic associations that have been reported with ADRs and discuss the challenges that scientists, clinicians, pharmaceutical industry and regulatory agencies face when attempting to translate these associations into clinically valid and cost-effective tests to reduce the burden of ADRs in future.

Association analysis of drug metabolizing enzyme gene polymorphisms in HIV-positive patients with co-trimoxazole hypersensitivity.

The use of co-trimoxazole in HIV-positive patients has been associated with a high frequency (40-80%) of hypersensitivity reactions. This has been attributed to the bioactivation of the sulphonamide component, sulphamethoxazole (SMX), to its toxic hydroxylamine and nitroso metabolites. The aim of this study was to determine whether functionally significant polymorphisms in the genes coding for enzymes involved in SMX metabolism influence susceptibility to SMX hypersensitivity. HIV-positive patients with (n = 56) and without (n = 89) SMX hypersensitivity were genotyped for allelic variants in CYP2C9, GSTM1, GSTT1, GSTP1 and NAT2 using polymerase chain reaction (PCR) and/or PCR-restriction fragment length polymorphism analysis. The CYP2C9*2/*3 genotype and CYP2C9*3 allele frequencies were nine- and 2.5-fold higher in the hypersensitive group compared to non-sensitive patients, respectively, although they were not statistically significant when corrected for multiple testing. There were no differences in the frequencies of the GSTM1 and GSTT1 null genotypes, and the slow acetylator genotype, between hypersensitive and non-sensitive patients, while GSTP1 frequency was lower (although non-significant) in the hypersensitive group [21% versus 32%, odds ratio (OR) = 0.5, Pc = 0.24]. Comparison of the genotype frequencies in HIV-positive and -negative patients showed that the NAT2 slow acetylator genotype frequency in the HIV-positive patients (74%) was significantly (Pc = 0.0003, OR = 2.3) higher than in control subjects (56%). Our results show that genetic polymorphisms in drug metabolizing enzymes are unlikely to be major predisposing factors in determining individual susceptibility to co-trimoxazole hypersensitivity in HIV-positive patients.

Phenotype standardization of angioedema in the head and neck region caused by agents acting on the angiotensin system.

Angioedema is a potentially life-threatening adverse reaction to angiotensin-converting enzyme inhibitors and angiotensin receptor blockers. To study the genetic etiology of this rare adverse event, international consortia and multicenter recruitment of patients are needed. To reduce patient heterogeneity, we have standardized the phenotype. In brief, it comprises swelling in the head and neck region that first occurs during treatment. It should not coincide with urticaria or have another likely cause such as hereditary angioedema.

Phenotype standardization for statin-induced myotoxicity.

Statins are widely used lipid-lowering drugs that are effective in reducing cardiovascular disease risk. Although they are generally well tolerated, they can cause muscle toxicity, which can lead to severe rhabdomyolysis. Research in this area has been hampered to some extent by the lack of standardized nomenclature and phenotypic definitions. We have used numerical and descriptive classifications and developed an algorithm to define statin-related myotoxicity phenotypes, including myalgia, myopathy, rhabdomyolysis, and necrotizing autoimmune myopathy.

Predictive genetic testing for drug-induced liver injury: considerations of clinical utility.

Genetic predisposition to drug-induced liver injury may be due to variation in both pharmacokinetic and pharmacodynamic pathways. Recent genome-wide association studies have identified, in the human leukocyte antigen (HLA) alleles, strong genetic factors that predispose to liver injury on exposure to any of several drugs. Although the genetic associations have provided mechanistic insights, none has been developed as a predictive test. Further work in this area, in combination with other "-omics" technologies, is needed to develop tests that are both clinically useful and cost-effective.

HLA genotype and carbamazepine-induced cutaneous adverse drug reactions: a systematic review.

Carbamazepine (CBZ) therapy is associated with cutaneous adverse reactions in up to 10% of patients. Predisposition to these hypersensitivity reactions has been linked to the human leukocyte antigen (HLA) genotype. This systematic review determines the strength of these associations and accuracy of proposed genetic screening. We determined that carriage of HLA-B*1502 in Asian patients was associated with a pooled odds ratio (OR) of 113.4 (95% confidence interval (CI) = 51.2-251.0, P < 1 × 10(-5)) for CBZ-induced Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). A total of 461 patients would need to be screened for HLA-B*1502 to prevent one episode of SJS/TEN. HLA-A*3101 is significantly associated with all phenotypes of CBZ hypersensitivity in multiple ethnicities with a pooled OR of 9.5 (95% CI = 6.4-13.9, P < 1 × 10(-5)). Between 47 and 67 patients would need to be tested for HLA-A*3101 to prevent one episode of hypersensitivity. Our findings suggest that HLA testing before carbamazepine therapy would be effective at identifying individuals at risk of hypersensitivity and applicable to multiple populations providing hope for prevention in the future.

The d3/fl-GH receptor gene polymorphism does not influence quality of life and body composition in GH-deficient adults receiving GH replacement therapy.

CONTEXT: The growth response to recombinant human growth hormone (rhGH) in GH deficient (GHD) patients may be influenced by polymorphisms in the growth hormone receptor (GHR) gene. OBJECTIVES: To investigate adults with GHD who have been treated with rhGH for more than 1 year to determine the relationship between genomic deletion of exon 3 in the GHR gene and quality of life (QoL), body composition (BC) and serum IGF1 levels, and to compare these variables to a healthy adult control population. DESIGN: Cross-sectional study. METHODS: A total of 100 healthy adult controls and 131 patients were studied. Deletion of exon 3 in the GHR gene was determined in DNA that was isolated from peripheral blood. QoL was determined using the adult GHD assessment scale and three other validated QoL instruments. RESULTS: In the control population, the frequency of the genotypes was 53% fl/fl, 40% d3/fl and 7% d3/d3, and in the patient population, 55, 39 and 6% respectively. There was no significant difference in QoL scores and BC in control subjects with the fl/fl genotype compared with those with the d3/d3 or fl/d3 genotype. There was no difference in the rhGH dose required to optimize serum IGF1, QoL or BC in patients with the fl/fl genotype compared with those with the d3/d3 or d3/fl genotype. CONCLUSION: Deletion of exon 3 in the GHR gene does not influence adult height, QoL or BC of the normal adult population nor does it influence rhGH dose, QoL and BC in GHD adults treated with rhGH for more than 1 year.

Correlation between bone scans and serum levels of osteocalcin, prostate-specific antigen, and prostatic acid phosphatase in monitoring patients with disseminated cancer of the prostate.

Response of prostatic cancer bone metastases to therapy (androgen withdrawal and Estracyt) was studied in 43 patients by applying scintiscanning and radioimmunodetective measurement of serum osteocalcin (OC) values. The prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP) concentrations, as sensitive probes for the overall tumor spread, were used in parallel in a monitoring procedure. A significant rise in OC levels to values elevated from a pretreatment normal level has been found in patients with a partial osseous tumor remission, and this may be easily distinguished from normal and/or subnormal OC level in bony tumor progression (P less than 0.01) and during stabilization in metastatic spread (P less than 0.01). On these bases, differences between disease progression and the "no change" response category could not be statistically recognized (P greater than 0.05). A sharp increase in circulating OC level has been recorded 1 months after the beginning of the treatment leading to bone remodeling processes and precedes improvements in scintiscan appearance. Blood OC concentration seems also to be of utility 1) in distinguishing scintigraphic flare phenomenon from a slight bone scan progression and 2) when related to scans with regions of both disease improvement and worsening. Furthermore, serum OC concentration can frequently be measured through a noninvasive procedure, thus serving as a significant addition to bone scintigraphy.