Predictive factors for identifying macrolide responder in treating chronic rhinosinusitis.

BACKGROUND: Low-dose macrolides (LDM) are anti-inflammatory agents with antineutrophilic activity, but patient selection for LDM therapy in treating chronic rhinosinusitis (CRS) is controversial. This study aimed to assess factors which predict LDM responders. METHODOLOGY: A prospective cohort study was performed. Patients with CRS received roxithromycin (150 mg) once daily for 12 weeks. Nasal secretions and serology were collected. Nine predictors for LDM response were assessed: nasal secretion IgE, nasal secretion IL-5, serum IgE, serum eosinophils, serum neutrophils, nasal polyps, asthma, allergy, and aspirin hypersensitivity, using receiver-operating curve analysis and multivariable logistic regression. Macrolide responders were those with sino-nasal outcome test-22 improvement, symptoms visual analogue scale decreased to ≤ ≤ ≤5, and no rescue medication. RESULTS: One hundred CRS patients (mean age 47.4 +- 14.1 years, 45% male) were enrolled. Univariable logistic regression showed local total IgE less than 5.21; and serum eosinophils less than 2.2% associated with macrolide response. Multivariate models showed local total IgE maintained an independent association with macrolide response, with an ability to discriminate between responders and non-responders of 63%. Serum total IgE, nasal secretion IL-5, serum neutrophil, nasal polyp, asthma, allergy, and aspirin hypersensitivity showed no association with LDM response. CONCLUSIONS: Low total IgE level in the nasal secretion but not in the serum, predict LDM response.

The minor house dust mite allergen Der p 13 is a fatty acid-binding protein and an activator of a TLR2-mediated innate immune response.

BACKGROUND: The house dust mite (HDM) allergen Der p 13 could be a lipid-binding protein able to activate key innate signaling pathways in the initiation of the allergic response. We investigated the IgE reactivity of recombinant Der p 13 (rDer p 13), its lipid-binding activities, and its capacity to stimulate airway epithelium cells. METHODS: Purified rDer p 13 was characterized by mass spectrometry, circular dichroism, fluorescence-based lipid-binding assays, and in silico structural prediction. IgE-binding activity and allergenic potential of Der p 13 were examined by ELISA, basophil degranulation assays, and in vitro airway epithelial cell activation assays. RESULTS: Protein modeling and biophysical analysis indicated that Der p 13 adopts a ß-barrel structure with a predominately apolar pocket representing a potential binding site for hydrophobic ligands. Fluorescent lipid-binding assays confirmed that the protein is highly selective for ligands and that it binds a fatty acid with a dissociation constant typical of lipid transporter proteins. The low IgE-binding frequency (7%, n = 224) in Thai HDM-allergic patients as well as the limited propensity to activate basophil degranulation classifies Der p 13 as a minor HDM allergen. Nevertheless, the protein with its presumptively associated lipid(s) triggered the production of IL-8 and GM-CSF in respiratory epithelial cells through a TLR2-, MyD88-, NF-kB-, and MAPK-dependent signaling pathway. CONCLUSIONS: Although a minor allergen, Der p 13 may, through its lipid-binding capacity, play a role in the initiation of the HDM-allergic response through TLR2 activation.

The association of single nucleotide polymorphism within vascular endothelial growth factor gene with systemic lupus erythematosus and lupus nephritis.

There were no statistically significant difference in allele and genotype frequency of the polymorphisms within the vascular endothelial growth factor (VEGF) gene (-460 and +405) between 193 systemic lupus erythematosus patients and 234 healthy controls. However, the +405 GG was significantly associated with lupus nephritis (LN) patients with low VEGF mRNA expression and LN with end-stage renal disease.

An investigation of the relationship between serotonin transporter gene promoter polymorphism and psoriasis susceptibility in a Thai population.

The serotonin transporter (5-HTT) is of great significance in the control of the serotonergic system, and its expression is known to be upregulated in psoriasis, a chronic or recurrent inflammatory skin disease. We investigated a possible association between the 5-HTT gene-linked polymorphic region (5-HTTLPR) and psoriasis in a Thai population. One hundred and fifty-six psoriatic patients and 156 unrelated healthy controls from Bangkok were genotyped using PCR. We found no overall differences in genotype distributions or allele frequencies between the two groups. In addition, when subgroups of psoriatic patients classified by either onset or severity were analyzed, no significant association between this polymorphism and any subgroup was observed. We conclude that 5-HTTLPR is not associated with susceptibility to psoriasis in this Thai population.

Up-regulation of Id1 in peripheral blood of psoriatic patients.

Although the precise causes of psoriasis are unclear, it is widely accepted that psoriasis is a disorder in which factors in the immune system, enzymes, and other biochemical substances that regulate skin cell division are impaired, leading to rapid proliferation of keratinocytes and incomplete keratinization. Expression of the helix-loop-helix transcription factor Id1 (inhibitor of differentiation/DNA binding), functioning as an inhibitor of differentiation, is known to increase in psoriatic skin. However, the molecular involvement of this particular biomarker in the psoriatic immune system remains to be elucidated. We measured Id1 mRNA expression in peripheral blood mononuclear cells (PBMCs) of psoriatic patients and healthy controls using semi-quantitative reverse transcriptase-PCR. The normalized level of Id1 transcripts in psoriatic patients was about 2-fold higher than that in controls (P < 0.05). When we examined the proliferation rate of PBMCs, the stimulation index obtained from the phytohemagglutinin stimulation assay was not significantly different in psoriatic patients. In patients with psoriasis, there was no correlation between the stimulation index and the psoriasis area severity index. We suggest that Id1 has a role in causing psoriatic immune cell symptoms.

Association between the -1438A/G polymorphism of the serotonin 2A receptor gene and late-onset psoriasis in a Thai population.

Expression of serotonin 2A receptor (5-HTR2A) is known to increase in psoriasis, a chronic inflammatory skin disease. We investigated a possible association between the -1438A/G single nucleotide polymorphism (rs6311) in the promoter region of 5-HTR2A gene and psoriasis in a Thai population. One hundred and twelve psoriatic patients and 151 unrelated healthy controls were included in our study. Genotyping was performed using the polymerase chain reaction and restriction fragment length polymorphism techniques. We found no overall differences in genotype distributions and allele frequencies when comparing between the two groups. When we analyzed a subset of psoriatic patients classified by onset and severity, only the -1438A allele was significantly increased in patients with late-onset psoriasis when compared with the healthy control group (chi(2) = 4.77, d.f. = 1, P = 0.029, odds ratio = 2.298 [95% confidence interval = 1.126-4.691]). This single nucleotide polymorphism may be involved in late-onset psoriasis in this Thai population.

Genetic association of interferon-alpha subtypes 1, 2 and 5 in systemic lupus erythematosus.

In this study, the association between the systemic lupus erythematosus (SLE) susceptibility and the new candidate genes, IFNA1, IFNA2 and IFNA5 genes, major interferon-alpha subtypes, in responses to viral infection was investigated. Allele and genotype frequencies of each marker were compared between 150 SLE patients and 150 healthy control subjects. This study indicated that the A/A genotype of IFNA5 (-2529) and the G/G genotype of IFNA1 (-1823) were associated with the protection of SLE disease in a recessive model [P(c) = 0.03, P = 0.01, odds ratio (OR) = 0.4, 95% confidence interval (CI) = 0.2-0.8 and P(c) = 0.09, P = 0.03, OR = 0.5, 95% CI = 0.2-0.9, respectively). Multifactor dimensionality reduction analysis showed a marginal interaction between IFNA5 (-2529) and IFNA1 (-1823) gene, with a cross-validation consistency of 10 of 10 and a prediction error of 46% (permutation P-value = 0.05). This is the first report of positive association of IFNA gene in SLE, especially the role of specific subtypes IFNA1 and IFNA5.

Association of the CTG (-2578/-460/+405) haplotype within the vascular endothelial growth factor gene with early-onset psoriasis.

Polymorphism of vascular endothelial growth factor (VEGF) influences the VEGF production and is subjected to genetic susceptibility of many diseases including psoriasis. Three single nucleotide polymorphisms (SNPs) within the promoter and exon 1 region [-2578(C/A), -460(C/T) and +405(C/G)] were analyzed in 154 patients with chronic plaque psoriasis and in 234 ethnically matched healthy controls from Thailand. The CTG (-2578/-460/+405) haplotype frequency was higher in patients with early-onset psoriasis (44.12%) compared with healthy controls (33.33%) (odds ratio = 1.54, 95% confidence interval = 1.08-2.18, P = 0.016, corrected P value: P(c) = 0.048). The results suggest that the CTG haplotype can be used as a genetic marker for psoriasis especially the early-onset group of Thais.

Association of the interleukin-10 distal promoter (-2763A/C) polymorphism with late-onset psoriasis.

Polymorphisms of the IL-10 promoter have been implicated in the genetic susceptibility to many autoimmune diseases, including psoriasis. Four putative functional single-nucleotide polymorphisms (SNPs) within the interleukin-10 promoter region (-3575T/A, -2763A/C, -1082G/A and -592C/A) were analysed in 139 patients with chronic plaque psoriasis and in 155 unrelated healthy controls from Thailand. There were no significant differences in the allele frequencies of any of the four SNPs between patients with psoriasis and controls. However, the frequency of the -2763A allele was increased in patients with late-onset psoriasis compared with controls and patients with early-onset psoriasis [OR=2.94, 95% CI 1.16-7.39, corrected P value (Pc)=0.04 and OR=3.26, 95% CI 1.13-9.51, Pc=0.048, respectively]. The AAGC (-3575/-2763/-1082/-592) haplotype frequency was higher in late-onset compared with early onset psoriasis (OR=4.37, 95% CI 1.24-15.97, Pc=0.027). This study suggests that the -2763A allele and the extended AAGC haplotype can be used as a genetic marker for susceptibility to late-onset psoriasis in a Thai population.

Genetic susceptibility to SLE is associated with TNF-alpha gene polymorphism -863, but not -308 and -238, in Thai population.

The production of cytokine varies among individuals and correlates with the polymorphism of cytokine genes. Three functional single nucleotide polymorphisms (SNPs) at position -863, -308, and -238 in the tumour necrosis factor alpha (TNF-alpha) gene promoter were analysed for association with systemic lupus erythematosus (SLE) (n = 154), and clinical manifestations in a Thai population were compared with 154 ethnically matched controls. The genotyping was determined by polymerase chain reaction-restriction fragment length polymorphism method. The association between these SNPs and SLE was analysed using chi-squared test. The -863A allele and -863A, -308G, -238G haplotype were found to be significantly increased in SLE patients (25%) compared with healthy controls (15.3%) (Pc = 0.009, OR = 1.85, 95% CI = 1.21-2.83). In addition -863A allele was found to be significantly increased in the SLE group with Raynaud's phenomenon compared to SLE without Raynaud's phenomenon (35% vs. 19.4%) (Pc = 0.048, OR = 2.23, 95% CI = 1.21-4.10). The -863A allele of TNF-alpha gene and the extended haplotype of -863A, -308G, -238G can be used as a genetic marker for SLE susceptibility in Thai populations. In addition, the -863A genotype could produce high TNF levels and potentially induce the occurrence of Raynaud's phenomenon.

The synergistic effect of FC gamma receptor IIa and interleukin-10 genes on the risk to develop systemic lupus erythematosus in Thai population.

Several linkage analyses have consistently shown that systemic lupus erythematosus (SLE) susceptible genes are located on chromosome 1q21-44. In this study, two major candidate genes, interleukin-10 (IL-10) and Fc gamma receptor IIa (FcgammaRIIa), within these regions were investigated in Thai SLE patients. The genotyping of three single-nucleotide polymorphisms (promoter area: -1082, -819 and -592) within IL-10 gene and one polymorphism (change amino acid at position 131) within FcgammaRIIa gene was determined in 195 SLE patients and 159 ethnically matched controls. The RR/RH genotypes of FcgammaRIIa were found to be significantly increased in SLE patients compared with healthy controls [OR = 2.01, 95% confidence interval (CI) = 1.28-3.14, P= 0.001]. Interestingly, the synergistic effect between RR/RH genotypes of FcgammaRIIa and ACC/ACC haplotype of IL-10 in susceptibility to SLE was observed (OR = 7.84, 95% CI = 1.60-52.04, P= 0.002). In addition, the FcgammaRIIa, RR homozygotes was also strongly associated with anticardiolipin antibody production (OR = 6.09, 95% CI = 1.38-30.54, P= 0.006). The result demonstrated that ACC haplotype of IL-10 gene and FcgammaRIIa R131 polymorphism can be used as marker for genetic susceptibility and severity to SLE in Thai population, particularly individuals carrying both specific genotypes.