Variant MBL2 genotypes producing low mannose-binding lectin may increase risk of Bacillus Calmette-Guerin osteitis in vaccinated newborns

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.

Interferon-gamma-dependent Immunity in Bacillus Calmette-Guérin Vaccine Osteitis Survivors

BACKGROUND

Inborn errors of interferon-gamma (IFN-γ)-mediated immunity underlie disseminated disease caused by Mycobacterium bovis Bacillus Calmette-Guérin (BCG) live vaccines. We hypothesized that some patients with osteitis after BCG vaccination may have an impaired IFN-γ immunity. Our aim was to investigate interleukin (IL)-12 and IFN-γ ex vivo production stimulated with BCG and BCG + IFN-γ or BCG + IL-12, respectively, in BCG osteitis survivors.

METHODS

Fresh blood samples were collected from 132 former BCG osteitis Finnish patients now aged 21-49 years, and IL-12 and IFN-γ were measured in cell cultures with and without stimulation with BCG and with BCG + IFN-γ or BCG + IL-12, respectively. As a pilot study, known disease-causing genes controlling IFN-γ immunity (IFNGR1, IFNGR2, STAT1, IL12B, IL12RB1, ISG15, IRF8, NEMO and CYBB) were investigated in 20 selected patients by whole exome sequencing.

RESULTS

By the limit of <5th percentile, ex vivo IL-12 concentration and increase in concentration was low in 5 and ex vivo IFN-γ concentration and increase in concentration was low in 6 patients (including 2 samples with both IL-12 and IFN-γ findings). By the limit of <10th percentile, an additional 6 and 4 patients were, respectively, detected (including 2 samples with both findings). With 2 exceptions, low concentrations and low increases in concentrations picked-up the same cases. Mutations in known disease-causing IFN-γ-related genes were not found in any of these patients.

CONCLUSION

These findings call for searching of mutations in new genes governing IFN-γ-dependent immunity to live BCG vaccine.