MBL2 genetic polymorphisms in Italian children with adenotonsillar hypertrophy

Siblings' Risk of Adenoid Hypertrophy: A Cohort Study in Children

BACKGROUND

The aim of this study was to compare adenoid size in preschool-age siblings using flexible nasopharyngoscopy examination (FNE) when they reach the same age. The occurrence of adenoid symptoms in these patients was also analyzed. This study was conducted to analyze the adenoid size in siblings when they reach the same age and substantiate a correlation between adenoid hypertrophy (AH) and adenoid symptoms.

METHODS

We analyzed and reported on the symptoms, ENT examination results, and FNE of 49 pairs of siblings who were examined at the same age.

RESULTS

There was a strong association in adenoid size between siblings when they are at a similar age (r = 0.673, p < 0.001). Second-born children whose older sibling had IIIo AH (A/C ratio > 65%) had a risk of IIIo AH 26 times greater than patients whose older sibling did not have IIIo AH (OR = 26.30, 95% CI = 2.82-245.54). Over 90% of snoring children whose siblings had confirmed IIIo AH would develop IIIo AH by the time they reach the same age. Second-born children in whom snoring occurs and whose older siblings have a IIIo AH have about a 46 times higher risk of IIIo AH compared to patients who did not meet these two conditions (p < 0.001, OR = 46.67, 95% CI = 8.37-260.30).

CONCLUSIONS

A significant familial correlation between adenoid size in siblings when they reach the same age was shown. If the older sibling has a confirmed overgrown adenoid (IIIo AH) and their younger sibling presents adenoid symptoms, particularly snoring, it is highly probable that they will also have an overgrown adenoid.

Significant association between SCGB1D4 gene polymorphisms and susceptibility to adenoid hypertrophy in a pediatric population

BACKGROUND/AIM

Adenoid hypertrophy (AH) is chronic enlargement of the adenoid tissue. The pathophysiology of the disease is unclear. We analyzed SCGB1D4 gene polymorphisms in order to determine the effect of the variants or their genetic combinations on AH.

MATERIALS AND METHODS

We genotyped the SCGB1D4 (IIS) gene in 167 participants (95 children with AH and 72 controls) by performing DNA sequencing in blood samples.

RESULTS

We genotyped three single nucleotide polymorphisms (SNPs). In the analysis, we found that in the presence of those SNPs and the minor alleles of individual SNPs four haplotypes were associated with an increased risk of AH. In addition, those SNPs were significantly associated with asthma, allergy, sleep-disordered breathing, AH grade +4, and a high level of IgE. As indicated on multifactor dimensionality reduction analysis, single-locus (rs35328961), two-locus (rs35328961_rs56196602), and three-locus models (rs200327820_rs35328961_rs56196602) had the highest synergistic interaction effect on AH. The three-factor model was also significantly associated with some genotypes of rs35328961 and allergic-asthmatic AH.

CONCLUSION

SNPs of SCGB1D4 and their combinations are associated with an increased risk for developing AH. We highlighted the importance of genetic factors on AH and AH-related clinical phenotypes.

DEFB1 polymorphisms and susceptibility to recurrent tonsillitis in Italian children

INTRODUCTION

The tonsils are secondary lymphoid organs fundamental for immune system response against pathogens within the oral cavity. Tonsillitis refers to inflammation of the pharyngeal tonsils that may include the adenoids and the lingual tonsils and that can be acute, recurrent, and chronic. Viral or bacterial infections, as well as immunologic factors are the main trigger to tonsillitis and disease's chronicity: the host immune responses, especially the innate one, could play an important role in susceptibility to the disease.

OBJECTIVES

The current study aims at investigating the role of functional polymorphisms in the 5'UTR (c.-52G>A, c.-44G>C and c.-20G>A) of DEFB1 gene, encoding for the antimicrobial peptide human beta-defensin 1, in the predisposition to recurrent tonsillitis in children from North Eastern Italy.

RESULTS

No significant correlation was found between DEFB1 allele, genotype and haplotype frequencies and recurrent tonsillitis susceptibility with the exception of an increased risk to disease development in patients carrying DEFB1 rare haplotypes.

CONCLUSION

Our results may suggest that DEFB1 polymorphisms alone may not influence pathology susceptibility, however they could possibly concur, together with other factors involved in the genetic control of innate immune system, in the predisposition towards recurrent tonsillitis.

Manganese-superoxide dismutase and glutathione peroxidase 1 polymorphisms in recurrent tonsillitis and tonsillar hypertrophy

OBJECTIVES

To investigate the association of manganese-superoxide dismutase and glutathione peroxidase 1 polymorphisms with susceptibility to recurrent tonsillitis and tonsillar hypertrophy.

METHODS

The study consisted of 103 patients with recurrent tonsillitis, 105 patients with tonsillar hypertrophy and 106 control subjects with similar age and sex. Genomic DNA was extracted from peripheral leukocytes of whole blood which were obtained from all patients and control subjects. Genotyping was performed to identify MnSOD Ala-9Val and GPx1 Pro198Leu polymorphisms by a method based on PCR amplification and detection of polymorphisms with hybridization probes labeled with fluorescent dyes. Genotype and allele frequencies were compared between patients with recurrent tonsillitis and tonsillar hypertrophy and 106 healthy control subjects.

RESULTS

The genotype distribution of the MnSOD Ala-9Val single nucleotide polymorphism was significantly different for the controls and the recurrent tonsillitis patients (P=0.009). Whereas, no significant difference was found between the patients with tonsillar hypertrophy and the control group (P=0.369). The frequency of the MnSOD CC genotype was lower, and that of the T allele was significantly higher, in recurrent tonsillitis patients than in control subjects. In addition, the frequency of tonsillitis was significantly higher in recurrent tonsillitis patients with the MnSOD Ala-9Val polymorphism than the patients with wild-type (P=0.008). Also, no significant difference was found between patient groups and control subjects in the distribution of the genotype and allele frequency of the GPx1 Pro198Leu single nucleotide polymorphism.

CONCLUSIONS

The MnSOD Ala-9Val polymorphism causes susceptibility to recurrent tonsillitis in Turkish children. And we suggest that there may be a possible relation between local and recurrent infections or inflammation of the tonsillar tissue and the MnSOD Ala-9Val single nucleotide polymorphism in pediatric patients with RT.

A clinical case-control study on the association between mannose-binding lectin and susceptibility to HIV-1 infection among northern Han Chinese population

Mannose-binding lectin (MBL) is a key molecule of the innate immune system and a competent to bind carbohydrates of a variety of microorganisms, resulting in complement activation and opsonophagocytosis against various pathogens. However, there is no systemic investigation on the MBL's role in innate immune responses against HIV-1 infection among northern Han Chinese. This study investigated the association between MBL and HIV-1 infection susceptibility among northern Han Chinese. A total of 91 HIV-1 infected patients and 91 HIV-1 seronegative healthy individuals were recruited. Six polymorphisms of MBL2 gene were genotyped by pyrosequencing. The quantitative measurement of serum MBL concentration and MBL complex activity were performed by ELISA. The CD4+ T-cell counts were determined by flow cytometry. The plasma viral loads of 91 HIV-1 infected patients were determined by bDNA method. The results show that there is an association between MBL and HIV-1 infection susceptibility among northern Han Chinese. The individuals with B variant, low serum MBL concentration and low MBL complex activity are more susceptible to HIV-1 infection.

MBL expression in patients with recurrent tonsillitis

OBJECTIVE

We evaluated mannose binding lectin (MBL) protein production and histological localization, MBL2 gene expression and genotypes distribution in patients characterized by recurrent tonsillitis, with the aim of verifying the innate immune response to the infection and inflammation occurring in the tonsils.

METHODS

MBL2 exon 1 and promoter polymorphims were detected by PCR amplification and subsequent direct sequencing of the amplicons. Monoclonal antibodies to MBL were used on frozen sections of tonsils for the immunohistochemical localization of MBL protein. MBL Oligomer ELISA kit was used to quantify the level of MBL in the serum of the 30 patients with recurrent tonsillitis. Quantitative RT PCR for the evaluation of MBL2 expression of MBL high producers (HP), low producers (LP) and deficient producers (DP) was performed using the Hs00175093 gene-expression Assay on Demand.

RESULTS

The distribution of the MBL2 combined genotypes was as follows: 21 HP (70%; 15 HYA/HYA, 6 HYA/LXA), 6 LP (20%; 5 HYA/0, 1 LXA/LXA) and 3 DP (10%, all 0/0). MBL levels were directly correlated to the MBL2 combined genotypes: HP patients showed higher mean MBL concentration of 4044 ng/mL, LP patients were characterized by a mean of 905 ng/mL whereas those with DP combined genotype presented extremely low levels of MBL (mean value of 74 ng/mL) (p=0.0005). Immunohistochemistry performed on tonsils sections demonstrated that MBL was widely distributed throughout the surface of the basal lamina of all the 21 HP subjects. MBL was undetectable in situ in both LP and DP patients. MBL2 expression, although at very low levels, was found for the HP group, the LP and the DP group as well.

CONCLUSIONS

We confirmed the genotype-phenotype correlation of MBL2 gene exon 1 and promoter polymorphisms with the quantitative production of serum MBL, we reported a very low MBL2 expression at local level in tonsils and we determined the in situ localization of MBL in the basal lamina of the tonsils of patients who underwent to tonsillectomy. Our findings suggest an important role of MBL protein in the innate immune response of the tonsil to pathogens, as in recurrent infection and inflammation.