Haplotype of the Interleukin 17A gene is associated with osteitis after Bacillus Calmette-Guerin vaccination

Gene polymorphisms of IL-17A and bacterial meningitis in Angolan children

Interleukin (IL)-17 A plays a crucial role in protecting hosts from invading bacterial pathogens. In this study, we investigated if single nucleotide polymorphisms (SNPs) in IL-17A are associated with susceptibility and outcome of bacterial meningitis (BM) in Angolan children. The study sample comprised 241 confirmed BM patients and 265 controls, which were matched for age and ethnicity. Three IL-17A SNPs - rs2275913 (-197G > A), rs8193036 (-737C > T) and rs4711998 (-877 A > G) - were determined by high-resolution melting analysis (HRMA). The frequency of variant genotype rs4711998 was significantly higher in patients with BM caused by Haemophilus influenzae (odds ratio [OR] 3.5; 95% confidence interval [CI] 1.49-8.23; P = 0.0025) than in controls. Also, patients with BM caused by Gram-negative bacteria and who carried the variant genotype rs2275913 had a lower glucose level (P = 0.0051) in cerebrospinal fluid (CSF). Patients with BM caused by Streptococcus pneumoniae who carried the variant type rs8193036 had a reduced risk for severe neurological sequelae (OR: 0.14; 95% CI: 0.029-0.68; P = 0.0079), blindness (OR: 0.012; 95% CI: 0.012-0.87; P = 0.017) and ataxia (OR: 0.28; 95% CI: 0.091-0.83; P = 0.023). This study suggests an association of IL-17A genetic variations with susceptibility and outcome of bacterial meningitis in Angolan children.

Polymorphisms in IL-17A Gene and Susceptibility of Colorectal Cancer in Bangladeshi Population: A Case-Control Analysis

OBJECTIVE

Interleukin-17A (IL-17A) genetic polymorphisms are associated with multiple cancer types, including colorectal cancer (CRC). However, no previous study was performed in the Bangladeshi population to evaluate the association. Our study aimed to find the association between two IL-17A variants (rs10484879 C/A and rs3748067 G/A) and susceptibility of CRC.

METHODS AND MATERIALS

This retrospective case-control study comprised 292 CRC patients and 288 age, sex, and BMI matched healthy volunteers. Genotyping of both variants was done by the tetra-primer ARMS-PCR method, and the results were analyzed by the SPSS software package (version-25.0).

RESULTS

Logistic regression analysis indicated that in case of IL-17A rs10484879 polymorphism, AC and AA genotype carriers showed 2.44- and 3.27-times significantly increased risk for CRC development (OR = 2.44, P = .0008 and OR = 3.27, P = .0133, individually). A significant association was also observed for AC + AA genotype (OR = 2.58, P = .0001). Again, over-dominant and allelic model revealed statistically significant link to CRC risk (OR = 2.13, P = .0035 and OR = 2.22, P = .001). For rs3748067 polymorphism, AG and AA genotype carriers showed 2.30- and 2.45-times enhanced risk for CRC (OR = 2.30, P = .005 and OR = 2.45, P = .031). A statistically significant association was also observed for AG + AA genotype (OR = 2.35, P = .001), over-dominant model (OR = 2.05, P = .014), and allelic model (OR = 2.11, P = .0004).

CONCLUSION

This study highlights that IL-17A rs10484879 and rs3748067 polymorphisms may be associated with CRC development. However, further functional research with larger samples may reveal more statistically significant outcomes.

The sixty-year story of Finnish Bacillus Calmette-Guérin (BCG) osteitis

AIM

A review published in 2015 showed that 331 Bacillus Calmette-Guérin (BCG) osteitis cases were globally reported in 1976-2012. The 222 Finnish cases from 1960 to 1988 formed two-thirds of all cases. The present narrative review summarises epidemiological, clinical and immunological findings obtained from this Finnish cohort in relation to data from other countries.

METHODS

Six reports including 93 BCG osteitis cases, which were not included in the 2015 review, were identified from PubMed.

RESULTS

In all, 424 BCG osteitis cases have been published. Population-based data were available only from Finland and Taiwan. The BCG osteitis incidence in Finnish infants was 6.4/100 000/year in 1960-1988 compared to 3.4/100 000/year in Taiwanese infants in 1998-2012. The incidence in Finland increased to 36.9/100 000 in 1971-1977, and the vaccinations were temporarily discontinued. Over half of lesions were in lower limbs and nearly all were solitary in both cohorts. The outcomes after surgery and chemotherapy were good. Immunology of BCG osteitis was studied only in the Finnish cohort. There were deviations from population data in polymorphisms of genes regulating Toll-like receptors 1, 2 and 6, mannose-binding lectin and interleukin-17A.

CONCLUSION

BCG osteitis after vaccination is rare. Preliminary findings in innate immunity raise a question of genetic background.

Interleukin 17F gene variations showed no association with BCG osteitis risk after newborn vaccination

AIM

Interleukin-17 (IL-17) family cytokines promote the host defence against mycobacterial infections. We have previously shown an association between IL17A variations and Bacillus Calmette-Guérin (BCG) osteitis. This paper evaluates the association of three IL17F polymorphisms with BCG osteitis after newborn vaccination.

METHODS

IL17F rs763780, rs11465553 and rs7741835 single nucleotide polymorphisms (SNPs) were studied in 132 adults, who presented with BCG osteitis in infancy. The genotypes and minor allele frequencies (MAFs) were compared between cases and Finnish population-based controls (N = 99) from the 1000 Genomes Project, and MAFs were compared between cases and allele data of Finnish subjects from the large Genome Aggregation Database.

RESULTS

There were no significant differences between former BCG osteitis patients and population-based controls in the IL17F rs763780 (wild 84.4% vs 84.8%), rs11465553 (86.4% vs 91.9%) or rs7741835 (65.7% vs 67.7%) genotypes. Homozygous variant genotypes were only present in 1.5%, 0.8% and 3.8% of cases, respectively. Likewise, MAFs of the three IL17F SNPs did not substantially differ from those of 11 252, 11 939 and 1371 Finnish subjects, respectively, from the available Genome Aggregation Database.

CONCLUSION

IL17F rs763780, rs11465553 and rs7741835 variations showed no association with the risk of BCG osteitis after newborn vaccination.

The impact of human single nucleotide polymorphisms on Bacillus Calmette-Guérin responses

The influence of genetic variability on human immune responses has major implications for the understanding of disease mechanisms and host-pathogen interactions. Bacillus Calmette-Guérin (BCG) vaccine, which is given globally to protect against tuberculosis, has high variability in its protective efficacy against mycobacteria and its beneficial off-target (heterologous) effects. Single nucleotide polymorphisms (SNPs) are major cause of genetic variation and have been strongly associated with susceptibility to tuberculosis and outcomes following BCG immunotherapy for cancer. This review discusses the contribution of SNPs to the variability in mycobacterial-specific and off-target BCG responses, and the implications for this on development of novel TB vaccines and strategies to harness the beneficial off-target effects of BCG.

First insight into the whole-genome sequence variations in Mycobacterium bovis BCG-1 (Russia) vaccine seed lots and their progeny clinical isolates from children with BCG-induced adverse events

Background

The only licensed live Bacille Calmette-Guérin (BCG) vaccine used to prevent severe childhood tuberculosis comprises genetically divergent strains with variable protective efficacy and rates of BCG-induced adverse events. The whole-genome sequencing (WGS) allowed evaluating the genome stability of BCG strains and the impact of spontaneous heterogeneity in seed and commercial lots on the efficacy of BCG-vaccines in different countries. Our study aimed to assess sequence variations and their putative effects on genes and protein functions in the BCG-1 (Russia) seed lots compared to their progeny isolates available from immunocompetent children with BCG-induced disease (mainly, osteitis).

Results

Based on the WGS data, we analyzed the links between seed lots 361, 367, and 368 used for vaccine manufacture in Russia in different periods, and their nine progeny isolates recovered from immunocompetent children with BCG-induced disease. The complete catalog of variants in genes relative to the reference genome (GenBank: CP013741) included 4 synonymous and 8 nonsynonymous single nucleotide polymorphisms, and 3 frameshift deletions. Seed lot 361 shared variants with 2 of 6 descendant isolates that had higher proportions of such polymorphisms in several genes, including ppsC, eccD5, and eccA5 involved in metabolism and cell wall processes and reportedly associated with virulence in mycobacteria. One isolate preserved variants of its parent seed lot 361 without gain of further changes in the sequence profile within 14 years.

Conclusions

The background genomic information allowed us for the first time to follow the BCG diversity starting from the freeze-dried seed lots to descendant clinical isolates. Sequence variations in several genes of seed lot 361 did not alter the genomic stability and viability of the vaccine and appeared accumulated in isolates during the survival in the human organism. The impact of the observed variations in the context of association with the development of BCG-induced disease should be evaluated in parallel with the immune status and host genetics. Comparative genomic studies of BCG seed lots and their descendant clinical isolates represent a beneficial approach to better understand the molecular bases of efficacy and adverse events during the long-term survival of BCG in the host organism.

Causality assessment of adverse events following immunization: the problem of multifactorial pathology

The analysis of Adverse Events Following Immunization (AEFI) is important in a balanced epidemiological evaluation of vaccines and in the issues related to national vaccine injury compensation programs. If manufacturing defects or vaccine storage and delivering errors are excluded, the majority of adverse reactions to vaccines occur as excessive or biased inflammatory and immune responses. These unwanted phenomena, occasionally severe, are associated with many different endogenous and exogenous factors, which often interact in complex ways. The confirmation or denial of the causal link between an AEFI and vaccination is determined pursuant to WHO guidelines, which propose a four-step analysis and algorithmic diagramming. The evaluation process from the onset considers all possible "other causes" that can explain the AEFI and thus exclude the role of the vaccine. Subsequently, even if there was biological plausibility and temporal compatibility for a causal association between the vaccine and the AEFI, the guidelines ask to look for any possible evidence that the vaccine could not have caused that event. Such an algorithmic method presents some concerns that are discussed here, in the light of the multifactorial nature of the inflammatory and immune pathologies induced by vaccines, including emerging knowledge of genetic susceptibility to adverse effects. It is proposed that the causality assessment could exclude a consistent association of the adverse event with the vaccine only when the presumed "other cause" is independent of an interaction with the vaccine. Furthermore, the scientific literature should be viewed not as an exclusion criterion but as a comprehensive analysis of all the evidence for or against the role of the vaccine in causing an adverse reaction. These issues are discussed in relation to the laws that, in some countries, regulate the mandatory vaccinations and the compensation for those who have suffered serious adverse effects.

Causality assessment of adverse events following immunization: the problem of multifactorial pathology

The analysis of Adverse Events Following Immunization (AEFI) is important in a balanced epidemiological evaluation of vaccines and in the issues related to vaccine injury compensation programs. The majority of adverse reactions to vaccines occur as excessive or biased inflammatory and immune responses. These unwanted phenomena, occasionally severe, are associated with many different endogenous and exogenous factors, which often interact in complex ways. The confirmation or denial of the causal link between an AEFI and vaccination is determined pursuant to WHO guidelines, which propose a four-step analysis and algorithmic diagramming. The evaluation process from the onset considers all possible "other causes" that might explain the AEFI and thus exclude the role of the vaccine. Subsequently, even if there was biological plausibility and temporal compatibility for a causal association between the vaccine and the AEFI, the guidelines ask to look for any possible evidence that the vaccine could not have caused that event. Such an algorithmic method presents several concerns that are discussed here, in the light of the multifactorial nature of the inflammatory and immune pathologies induced by vaccines, including emerging knowledge of genetic susceptibility to adverse effects. It is proposed that the causality assessment could exclude a consistent association of the adverse event with the vaccine only when the presumed "other cause" is independent of an interaction with the vaccine. Furthermore, the scientific literature should be viewed not as an exclusion criterion but as a comprehensive analysis of all the evidence for or against the role of the vaccine in causing an adverse reaction. Given these inadequacies in the evaluation of multifactorial diseases, the WHO guidelines need to be reevaluated and revised. These issues are discussed in relation to the laws that, in some countries, regulate the mandatory vaccinations and the compensation for those who have suffered serious adverse effects.