Mannose-binding Lectin Gene Polymorphisms Research Articles

Mannose-binding lectin gene polymorphisms in Brazilian patients with systemic lupus erythematosus

The mannose-binding lectin gene (MBL-2) has emerged as a candidate for systemic lupus erythematosus susceptibility, but studies in Brazilian population have not been conducted. To examine potential associations of mannose-binding lectin alleles G57E, G54D, IVSnt5, R52C and R52H with susceptibility to and clinical expression of systemic lupus erythematosus in southern Brazilian patients, we conducted a case-control study with 327 consecutive patients with diagnosis of systemic lupus erythematosus and 345 healthy controls. Genotyping was performed by restriction fragment length polymorphism-polymerase chain reaction assay. A statistically significant difference in the frequencies of allele R52C was observed in European-derived systemic lupus erythematosus patients when compared with controls (9.6% vs. 3.3%, p < 0.001, odds ratio: 3.15, 95% confidence interval: 1.76-5.62, p < 0.05). The frequencies of alleles G54D and G57E were not different between European-derived systemic lupus erythematosus patients and controls. There were no differences between clinical and laboratory features in systemic lupus erythematosus patients according to the presence or absence of mannose-binding lectin allelic variants. These results support an increased risk of systemic lupus erythematosus in European-derived individuals carrying allele R52C. Patients carrying this allele have an approximately three-fold higher odds ratio of developing systemic lupus erythematosus when compared with controls. Our data do not support associations between the mannose-binding lectin allelic variants studied and clinical expression of systemic lupus erythematosus.

Association of mannose-binding lectin gene polymorphisms with Kawasaki disease in the Japanese

Objective: Kawasaki disease (KD) is a systemic vasculitis in childhood; its etiology is unknown. The possibility that KD is an infectious disease has been discussed and investigated for decades, in light of the implication that infections are involved in the pathogenesis of KD. Young children rely on their innate immune system for protection against virus and micro‐organisms. Human mannose binding lectin (MBL) is a C‐type serum lectin synthesized by the liver as an acute phase protein and it plays an important role in the innate immune system. Here, we investigate the relationship between the MBL gene polymorphisms and the occurrence of KD in the Japanese population. Method: The frequencies of the genotypes, defined as mutations in codons 52, 54 and 57, and the functional promoter variants of the MBL were determined in 45 patients with KD. Results: The MBL codon‐54 polymorphism frequency of heterozygote (GGC/GAC) and promoter variants were significantly higher in the KD group than that in the control group (P < 0.05). Neither group showed codon 52 nor 57 polymorphisms. Conclusion: It is possible that mutations of the MBL gene might be related to the trigger of the pathogenesis of Kawasaki disease.

O6 Serum mannose binding lectin in SLE

Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). We characterized efficacy and safety of tofacitinib in Mexican patients from RA Phase 3 and long-term extension (LTE) studies.Data from Mexican patients with RA and an inadequate response to disease-modifying antirheumatic drugs (DMARDs) were taken from four Phase 3 studies (pooled across studies) and one open-label LTE study of tofacitinib. Patients received tofacitinib 5 or 10 mg twice daily, adalimumab (one Phase 3 study) or placebo (four Phase 3 studies) as monotherapy or in combination with conventional synthetic DMARDs. Efficacy up to Month 12 (Phase 3) and Month 36 (LTE) was assessed by American College of Rheumatology 20/50/70 response rates, Disease Activity Score (erythrocyte sedimentation rate), and Health Assessment Questionnaire-Disability Index. Safety, including incidence rates (IRs; patients with events/100 patient-years) for adverse events (AEs) of special interest, was assessed throughout the studies.119 and 212 Mexican patients were included in the Phase 3 and LTE analyses, respectively. Tofacitinib-treated patients in Phase 3 had numerically greater improvements in efficacy responses versus placebo at Month 3. Efficacy was sustained in Phase 3 and LTE studies. IRs for AEs of special interest were similar to those with tofacitinib in the global and Latin American RA populations.In Mexican patients from the tofacitinib global RA program, tofacitinib efficacy was demonstrated up to Month 12 in Phase 3 studies and Month 36 in the LTE study, with a safety profile consistent with tofacitinib global population.Tofacitinib es un inhibidor de la cinasa Janus para el tratamiento de la artritis reumatoide (AR). Se evaluaron la eficacia y la seguridad de tofacitinib en pacientes mexicanos a partir de los estudios fase 3 y de extensión a largo plazo (ELP) de AR.Datos de pacientes mexicanos con AR y respuesta inadecuada a fármacos antirreumáticos modificadores de la enfermedad (FARME) fueron tomados de 4 estudios fase 3 y de un estudio abierto de ELP de tofacitinib. Los pacientes recibieron tofacitinib 5 o 10 mg 2 veces al día, adalimumab (en un estudio fase 3) o placebo (en 4 estudios fase 3) como monoterapia o en combinación con FARME sintético convencional. Se evaluó la eficacia al mes 12 (fase 3) y al mes 36 (ELP) por medio de las tasas de respuesta del Colegio Americano de Reumatología 20/50/70, el puntaje de actividad de la enfermedad (DAS) 28-4, velocidad de sedimentación globular y el índice de discapacidad del cuestionario de evaluación de la salud (HAQ-DI). Se evaluó la seguridad a través de los estudios, incluyendo tasas de incidencia (IR; pacientes con evento/100 pacientes-año).Ciento diecinueve y 212 pacientes mexicanos fueron incluidos en el análisis de los estudios fase 3 y de extensión a largo plazo, respectivamente. Pacientes tratados con tofacitinib en los estudios fase 3, numéricamente, tuvieron una mayor mejoría en las respuestas de eficacia en comparación con el placebo al mes 3. La eficacia fue sostenida en los estudios fase 3 y de extensión a largo plazo. Las tasas de incidencia de los eventos adversos de especial interés fueron similares a aquellas con tofacitinib en la población global y latinoamericana.En pacientes mexicanos del programa global de tofacitinib en AR, la eficacia de tofacitinib se demostró hasta el mes 12 en los estudios fase 3 y hasta el mes 36 en el estudio de extensión a largo plazo, con un perfil de seguridad consistente con el de la población global de los estudios de tofacitinib.

Systemic lupus erythematosus as a first presentation of common variable immunodeficiency associated with infrequent mannose-binding lectin gene polymorphisms

The association of common variable immunodeficiency (CVID) and systemic lupus erythematosus (SLE) is infrequent. Mannose-binding lectin (MBL) has been shown to play a role in CVID and SLE. The purpose of this study is to describe two cases of CVID who presented as SLE and also evaluate the presence of MBL polymorphisms and MBL serum levels in those patients. In both patients, SLE was the first manifestation of CVID. In these patients the SLE immunological markers and disease activity disappeared after the development of CVID. They carried the very infrequent MBL haplotype 4Q-57Glu. One of them had a homozygous genotype, whereas the other patient was heterozygous and also presented the haplotype 4P-57Glu that had never been previously detected. Interestingly, this last patient was presenting frequent respiratory tract infections, developed bronchiectasis and had low levels of circulating MBL. These results may support the role of MBL in the development of autoimmunity in CVID. Further genetic studies are needed to clarify the role of the MBL polymorphisms in the development of autoimmunity in CVID.

Donor mannose-binding lectin gene polymorphisms influence the outcome of liver transplantation

Mannose-binding lectin (MBL) is a C-type lectin produced mainly by the liver that binds to a wide range of pathogens. Polymorphisms at the promoter and exon 1 of the MBL2 gene are responsible for low serum levels of MBL and have been associated with an increased risk of infections. We prospectively analyzed 95 liver transplant recipients. Well-known functionally relevant polymorphisms of the MBL2 gene of the liver donor were examined by gene sequencing. Infectious events were collected prospectively. No differences in the incidence of infections were found according to the donor MBL2 genotypes. Survival was lower in patients receiving a liver graft from a donor with an exon 1 MBL2 variant genotype, and they had higher infection-related mortality (50% versus 14%, P = 0.040). No differences were found according to other polymorphisms involving the promoter and 5'-untranslated region. When we analyzed bacterial infection episodes, we found that patients receiving a liver from a donor with an exon 1 variant genotype had a higher incidence of septic shock (46% versus 11%, P = 0.004). Independent variables associated with graft or patient survival were as follows: receiving a graft from a donor with an exon 1 MBL2 variant genotype [adjusted hazard ratio (aHR), 9.64; 95% confidence interval (CI), 2.59-36.0], the Model for End-Stage Liver Disease score (aHR, 1.14; 95% CI, 1.05-1.23), and bacterial infections (aHR, 11.1; 95% CI, 2.73-44.9). Liver transplantation from a donor with a variant MBL2 exon 1 genotype was associated with a worse prognosis, mainly because of infections of higher severity.

Influence of Mannose-Binding Lectin Gene Polymorphisms on The Invasiveness of Cytomegalovirus Disease After Solid Organ Transplantation

Mannose-binding lectin (MBL) is a component of the innate immune system that binds the surface of pathogens, activating the complement pathway and acting as opsonin. Certain single-nucleotide polymorphisms of MBL2 are associated with a decrease in the circulating levels of MBL. Our aim was to evaluate the influence of MBL2 polymorphisms in the invasiveness of Cytomegalovirus (CMV) disease after solid organ transplantation. We include those solid organ transplant recipients who developed CMV disease posttransplant from 2000 to 2006. MBL2 genotyping was performed by sequencing of exon 1 (wild-type allele A and variants B, C, and D) and promoter regions (alleles H and L, X and Y, and P and Q). In the case of liver transplantation, donor MBL2 genotypes were analyzed. Associations were calculated by the chi-square test and binary logistic regression. We included 45 transplant recipients with CMV disease (22 renal, 7 simultaneous kidney-pancreas, 11 liver, and 5 heart), of whom 10 (22%) had invasive CMV disease. No differences were found regarding HH (versus HL or LL), YY and YX (versus XX) and QQ (versus QP and PP) haplotypes with invasive CMV disease (P = 1.000 for all 3 comparisons). Patients with an exon 1 wild-type (AA) haplotype had 36% invasive CMV disease in comparison with 9% of patients with A/O or O/O haplotypes (P = .035). Binary logistic regression analysis showed that patients with exon 1 AA haplotype had an independent risk of developing invasive CMV disease (odds ratio, 6.0; 95% confidence interval, 1.1-32.5). Our results suggest that exon 1 wild-type genotypes are associated with a higher risk of invasive CMV disease after solid organ transplantation.

Mannose-binding lectin gene polymorphisms are not associated with susceptibility to hepatitis C virus infection in the Brazilian Amazon region

The present study compares the genotype frequencies between two population groups composed by 73 hepatitis C virus (HCV)-infected patients and 92 seronegative controls and investigates the role of allele variants as a possible factor in the susceptibility to HCV infection and the influence on disease progression. The identification of MBL*B and MBL*C alleles was performed by restriction fragment length polymorphism analysis of the 349-bp product using BanI and MboII restriction enzymes, respectively, and a polymerase chain reaction–sequence-specific polymorphism for discrimination of MBL*D. The analysis of allele and genotype frequencies between an HCV-infected group and seronegative controls did not indicate significant differences. The comparison of chronically infected subjects with and without liver cirrhosis was also not statistically significant. The odds ratio estimations were not significant, and the values obtained cannot suggest that the presence of allele variant MBL*B could have some influence in the risk of HCV infection progression to liver cirrhosis and that the presence of allele MBL*D could confer some protection against disease progression, but a larger sample size is necessary to confirm the present results.

Lack of association of mannose-binding lectin gene polymorphisms with development and clinical manifestations of systemic lupus erythematosus in Chinese children

Mannose-binding lectin (MBL) gene polymorphisms may be associated with adult-onset systemic lupus erythematosus (SLE), but studies in children with SLE are rare. This study tested the genetic association between MBL polymorphisms and paediatric-onset SLE in a cohort of Chinese children in Taiwan. In all 150 children with SLE and 100 healthy controls of comparable age were genotyped for codon 52, 54 and 57 mutations of the MBL gene using a polymerase chain reaction-based assay. Clinical manifestations, organ involvement, disease activity, laboratory characteristics and outcome were recorded and compared between patients with different MBL genotypes. Codon 54 mutation was fairly common in both SLE patients and controls, whereas codon 52 and codon 57 mutations were not detected in our study subjects. No statistically significant differences were found in allele frequencies of the codon 54 mutation between SLE and control groups. Moreover, no association was found between this MBL polymorphism and clinical manifestations, organ involvement, disease activity, laboratory characteristics or outcome of SLE. These results suggest that MBL polymorphisms do not influence susceptibility to paediatric-onset SLE and do not influence clinical manifestations of SLE in Chinese children.

Mannose Binding Lectin (+54) Exon 1 Gene Polymorphism in Tunisian Kidney Transplant Patients

Mannose-binding lectin (MBL), a collagen-like serum protein, is a key component of innate immunity. MBL binding to carbohydrates present on pathogens mediates lectin-dependent activation of the complement pathway. There is growing interest in the importance of innate immunity in host defense, particularly when adaptive immunity is compromised. Three single nucleotide polymorphisms (SNPs) of the MBL gene have been described in the first exon to be associated with low MBL serum concentrations as well as impaired MBL structure and function. Clinical studies have shown that these MBL SNPs are associated with increased susceptibility to infections, especially in immunocompromised patients. To investigate the association between acute kidney transplant rejection and polymorphism at codon 54 of the MBL gene, the DNA genomic of 133 renal transplant recipients and 117 healthy blood donors was analyzed by restriction fragment length polymorphism-polymerase chain reaction. The patients were classified into two groups: group 1 included 32 HLA-identical recipients and group 2, 101 one haplo-identical recipients. Forty-eight (36.1%) subjects had developed one or more acute rejection episodes (AREs) within the first 6 months after transplantation: 9 in group 1 (28.12%) and 39 in group 2 (38.61%). The genotype and allele frequencies of (+54) MBL gene polymorphism among patients and controls did not reveal a significant difference. However, the frequency of MBL–B mutant allele was increased among patients with AREs compared with those without AREs: group 1 (0.167 vs 0.065) versus group 2 (0.205 vs 0.105). Although the difference was not significant, perhaps because of the small number of patients, the MBL at codon (+54) polymorphism could be involved in the susceptibility of Tunisian kidney transplant recipients to acute allograft rejection episodes.

Mannose-Binding Lectin Gene Polymorphisms Are Associated with Disease Activity and Physical Disability in Untreated, Anti-Cyclic Citrullinated Peptide-Positive Patients with Early Rheumatoid Arthritis

To study the association between polymorphisms in the mannose-binding lectin gene (MBL2) and disease activity, physical disability, and joint erosions in patients with newly diagnosed rheumatoid arthritis (RA). Patients with early RA (n=158) not previously treated with disease modifying antirheumatic drugs, participating in a treatment trial (CIMESTRA study) were examined at inclusion for MBL2 pooled structural genotypes (O/O, A/O, A/A), regulatory MBL2 promoter polymorphism in position -221 (XX, XY, YY), anti-cyclic citrullinated peptide 2 antibodies (anti-CCP2), disease activity by Disease Activity Score-28 (DAS28 score), physical disability by Health Assessment Questionnaire (HAQ) score, and erosive changes in hands and feet (Sharp-van der Heijde score). Eight patients were homozygous MBL2 defective (O/O), 101 belonged to an intermediate group, and 49 were MBL2 high producers (YA/YA). Anti-CCP was present in 93 patients (59%). High scores of disease activity, C-reactive protein-based DAS28 (p=0.02), and physical disability by HAQ (p=0.01) were associated with high MBL2 expression genotypes in a gene-dose dependent way, but only in anti-CCP-positive patients. At this early stage of the disease there was no association with erosion score from radiographs. The results point to a synovitis-enhancing effect of MBL in anti-CCP-positive RA, whereas such an effect was not demonstrated for joint erosions.

Mannose binding lectin gene polymorphisms and associated auto-immune diseases in type 1 diabetes Brazilian patients

In our study we investigated the possible role of MBL2 functional single nucleotide polymorphisms (SNPs) in the augmented susceptibility to develop other autoimmune diseases in presence of type 1 diabetes (T1D) in a group of Brazilian patients. Patients were stratified for the presence of autoimmune diseases known to be associated with T1D, such as autoimmune thyroid disease (AITD) and celiac disease (CD), and compared with healthy controls (HC). Our findings suggest that MBL2 functional SNPs are more closely related to AITD than to T1D, being MBL2 SNPs frequencies in T1D patients not affected by AITD comparable to the HC ones, while significantly different between AITD patients and patients not affected by the disease. Thus, the association between MBL2 polymorphisms and T1D that we previously reported, seems to result from the stronger association of MBL2 SNPs with another autoimmune disease, the AITD, frequently associated with T1D.

Mannose Binding Lectin Gene Polymorphism and the Severity of Chronic Periodontitis

Mannose binding lectin (MBL) is a key molecule in first line defense against various microorganisms. Polymorphism of the MBL gene greatly affects serum MBL concentration, and is known to be associated with occurrence of infectious diseases. We aimed to determine whether there is a relationship between occurrence or severity of chronic periodontitis (CP) and polymorphism of the MBL gene. Ninety-eight CP patients and 63 healthy subjects with no periodontitis were typed for the codon 54 polymorphism of the MBL gene by PCR-restriction fragment length polymorphism method. Genotype frequencies of the codon 54 polymorphism were similar between patients and control subjects. When patients were categorized to mild, moderate and severe periodontitis groups, possession of the low serum MBL concentration allele was a risk factor for having severe CP, as assessed by logistic regression analysis. Patients with MBL genotypes that cause lower serum MBL concentration may be at risk of having severe periodontitis. MBL gene typing may become useful to predict the prognosis of CP.

Mannose‐binding lectin gene polymorphisms in relation to periodontitis

To investigate the correlation of six functional polymorphisms in the MBL gene with MBL plasma levels in relation to periodontitis. A total of 92 periodontitis patients and 70 controls, all of Caucasian origin, were included. Patients and controls were genotyped for the L/H, X/Y, P/Q, A/D, A/B and A/C polymorphisms. Distributions of genotypes, rate of allele carriage and allele frequencies were compared between patients and controls. Patients and controls were subdivided in groups of genotypes. Plasma MBL levels were compared between different genotype groups. On the basis of genotyping, three phenotypes with regard to mannose-binding lectin (MBL) production were distinguished: high-producers, low-producers and deficient subjects. No differences in the genotype frequencies were observed between patients and controls. Within patients and controls, subjects with the high-producing genotypes had significantly higher MBL plasma levels than low-producers and deficient subjects (p<0.001). Plasma MBL was higher in low-producer patients compared with low-producer controls (p(adjusted)=0.021). No association could be observed between MBL gene polymorphisms and susceptibility to periodontitis in Caucasians. However, now that genotyping could distinguish the low producing and deficient subjects from the high-producers, it was observed, for the first time, that MBL acts as a weak acute-phase protein in periodontitis.

Association of Mannose-Binding Lectin Gene Polymorphism but Not of Mannose-Binding Serine Protease 2 with Chronic Severe Aortic Regurgitation of Rheumatic Etiology

N-Acetylglucosamine (GlcNAc) is the major immunoepitope of group A streptococcal cell wall carbohydrates. Antistreptococcal antibodies cross-reactive with anti-GlcNAc and laminin are present in sera of patients with rheumatic fever. The cross-reactivity of these antibodies with human heart valvular endothelium and the underlying basement membrane has been suggested to be a possible cause of immune-mediated valve lesion. Mannose-binding lectin (MBL) encoded by the MBL2 gene, a soluble pathogen recognition receptor, has high affinity for GlcNAc. We postulated that mutations in exon 1 of the MBL2 gene associated with a deficient serum level of MBL may contribute to chronic severe aortic regurgitation (AR) of rheumatic etiology. We studied 90 patients with severe chronic AR of rheumatic etiology and 281 healthy controls (HC) for the variants of the MBL2 gene at codons 52, 54, and 57 by using a PCR-restriction fragment length polymorphism-based method. We observed a significant difference in the prevalence of defective MBL2 alleles between patients with chronic severe AR and HC. Sixteen percent of patients with chronic severe AR were homozygotes or compound heterozygotes for defective MBL alleles in contrast to 5% for HC (P = 0.0022; odds ratio, 3.5 [95% confidence interval, 1.6 to 7.7]). No association was detected with the variant of the MASP2 gene. Our study suggests that MBL deficiency may contribute to the development of chronic severe AR of rheumatic etiology.

MANNOSE-BINDING LECTIN (MBL) GENE POLYMORPHISMS AND SERUM MBL LEVELS IN CHILDREN WITH RECURRENT RESPIRATORY TRACT INFECTION

INTRODUCTION: Mannose-binding lectin (MBL) is a plasma collectin and is considered an important component of innate immunity. Its plasma concentration is, for the most, part genetically determined by a series of single nucleotide polymorphisms located both in the structural gene and in the promoter region. MBL deficiency may be associated with increased susceptibility to infectious disease and autoimmune disorders. OBJECTIVE: Our goal was to establish the reference serum level of MBL in children, investigate the correlation between MBL gene polymorphisms and its serum level in Chinese Han nationality, and MBL gene polymorphisms and serum level in children with recurrent respiratory tract infections. METHODS: The concentrations of oligomerized MBL in plasma were measured by enzyme-linked immunosorbent assay, and MBL gene polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism and polymerase chain reaction with sequence-specific primers. RESULTS: The median MBL level in 470 normal children was 2536 ng/mL (range: 0–7860 ng/mL), and P2.5 to P97.5 was 161 to 5070 ng/mL. Two promoter polymorphisms, -550 and -221, and coding variants at codon 54 of the MBL gene affected the protein level significantly, and the most frequent genotype in Hans was HYPA/HYPA. Serum MBL levels were significantly lower in patients with recurrent respiratory tract infections (RRTIs) compared with healthy controls (H = 6.661; P &amp;lt; .05), and the frequency of the promoter LXP haplotype was significantly higher in patients with RRTIs than in controls (χ2 = 4.71; P = .03). The prevalence of the B allele in patients with RRTIs was higher than that in controls, but the difference did not reach significance (χ2 = 0.18; P &amp;gt; .05). CONCLUSIONS: The MBL reference value in China is 161 ng/mL. Children with MBL concentrations of &amp;lt;161 ng/mL, therefore, were deemed to be MBL deficient, and LXP is a risk factor for recurrent respiratory tract infections in this population.

TLR and MBL Gene Polymorphisms in Severe Acute Pancreatitis

Mannose-binding lectin (MBL) and toll-like receptor (TLR)-4 gene polymorphisms have been implicated in inflammatory episodes in a number of studies. In view of the inflammatory nature of acute pancreatitis, we aimed to determine the predictive value of two point mutations in the promoter region at position -550 (H/L variants) and -221 (X/Y variants) of the MBL2 gene, and the Asp299Gly and 119C>A polymorphisms of the TLR4 gene on the occurrence of severe acute pancreatitis (SAP). The study included 132 patients with SAP, 106 with mild acute pancreatitis (MAP), and 121 healthy volunteers. Genotypes were determined using restriction fragment length polymorphism analysis of PCR products and by allele-specific PCR. No significant difference in genotype frequency was noted between the patients with acute pancreatitis and controls for any of the gene loci studied. The distributions of the HY/HY, HY/LY, LY/LY, and LY/LX genotypes of MBL2 gene promoter and 119C>A genotype of the TLR4 gene were similar in patients with mild or severe acute pancreatitis. HY/LX genotype frequency was significantly higher in patients with SAP compared with MAP (26% vs 14%; p = 0.028). Results indicate that the MBL2 HY/LX genotype plays an important role in the determination of disease severity to acute pancreatitis.

RESEARCH OF MANNOSE-BINDING LECTIN AND INTERLEUKINS 10, 12, AND 18 IN CHILDREN WITH HENOCH-SCHÖNLEIN PURPURA

INTRODUCTION: Henoch-Schönlein Purpura (HSP) is a common vasculitis in children, and the unbalance of T-helper 1/T-helper 2 plays an important part in its pathogenesis. Mannose-binding lectin (MBL) is an important component of innate immunity and related with a lot of diseases with immunologic derangement. However, we do not know the relationship between MBL and HSP. OBJECTIVE: We aimed to explore the serum level and gene polymorphisms of MBL and the levels of interleukin 10 (IL-10), IL-12, and IL-18 in supernatant of peripheral blood mononuclear cells of children with HSP and HSP nephritis (HSPN) and of healthy children. METHODS: The concentrations of MBL and IL-10, IL-12, and IL-18 were measured by enzyme-linked immunosorbent assay: MBL gene polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism and polymerase chain reaction with sequence-specific primers. RESULTS: The serum MBL levels in the 23 children with HSP were not significantly different from 27 children with HSPN (P = .95) or 18 normal children. The levels of IL-18 in the supernatant of peripheral blood mononuclear cells in the 3 groups were not significantly different from each other (P = .47, .15, and .14). The levels of IL-10 in children with HSP and HSPN were not different from each other (P = .70), but both were significantly different from those in the normal children (P = .04 and .01). The levels of IL-12 in children with HSP were different from those in the children with HSPN (P = .04). The MBL promoter genotype and the frequency of alleles were not different between the children with HSP and HSPN or between those 2 groups compared with the normal group. CONCLUSIONS: IL-12 probably plays an important role in the renal involvement in HSP. The position of MBL in the pathogenesis of HSP and HSPN remains to be confirmed.

Association between primary vulvar vestibulitis syndrome, defective induction of tumor necrosis factor-α, and carriage of the mannose-binding lectin codon 54 gene polymorphism

We evaluated whether women with vulvar vestibulitis syndrome (VVS) could be subdivided on the basis of genotyping the polymorphic mannose-binding lectin (MBL) gene. DNA from 123 women with VVS was tested for a single nucleotide polymorphism at codon 54 of the MBL gene. Blood samples from 86 of the women were evaluated for ex vivo tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 receptor antagonist (IL-1ra) production in response to Candida albicans, gram-positive peptidoglycan, and gram-negative lipopolysaccharide. Associations between laboratory findings and clinical characteristics were analyzed. The variant MBL*B allele was identified in 33 subjects (26.8%). This polymorphism was more prevalent in women whose symptoms developed at their first act of sexual intercourse (primary VVS, 40.9%), as opposed to women with secondary VVS (16.3%; P = .01). Ex vivo TNF-alpha production, but not IL-1ra production, was reduced in MBL*B carriers as compared with MBL*A homozygotes (P < or = .03). The MBL gene polymorphism is associated with the development of primary VVS and a reduced capacity for TNF-alpha production in response to microbial components.

The role of mannose-binding lectin gene polymorphisms in women with recurrent bacterial vaginosis

The objective of the study was to examine mannose-binding lectin gene (MBL2) polymorphisms in women with recurrent episodes of bacterial vaginosis (BV). Seventy-one women with at least 4 episodes of BV in the last 12 months and 130 healthy controls were enrolled to evaluate all 3 variant alleles of the MBL2 gene (polymorphisms at positions 52, 54, and 57 in the first exon of the MBL2 gene). No statistically significant differences in MBL2 polymorphism allelic and genotype frequencies were observed between women with recurrent BV and controls. Allele A (wild type) was present, respectively, in 78% of patients with recurrent BV and 77% of controls, whereas the allele 0 was present in 22% of women with recurrent BV and 23% of controls. MBL2 genotype and allelic frequencies were similar in the 2 groups, and the 2 populations were in accordance with the Hardy-Weiberg equilibrium. Our results indicate that MBL2 gene polymorphisms do not seem to be involved in susceptibility to recurrences of BV in gynecological patients.

Low Pretransplantation Mannose-Binding Lectin Levels Predict Superior Patient and Graft Survival after Simultaneous Pancreas-Kidney Transplantation

Simultaneous pancreas-kidney transplantation (SPKT) is the treatment of choice for patients with type 1 diabetes and renal failure. However, this procedure is characterized by a high rate of postoperative infections, acute rejection episodes, and cardiovascular mortality. The lectin pathway of complement activation contributes to cardiovascular disease in diabetes and may play an important role in inflammatory damage after organ transplantation. This study therefore sought to determine how mannose-binding lectin (MBL), a major recognition molecule of the lectin pathway of complement activation, influences outcome after SPKT. MBL serum levels were determined in 99 and MBL genotypes in 97 consecutive patients who received an SPKT from 1990 through 2000 and related to patient and graft survival. At 12 yr, cumulative death-censored kidney graft survival was 87.5% in patients with an MBL level <400 ng/ml and 74.8% in the group with MBL levels >400 ng/ml (P = 0.021). Pancreas graft survival was significantly better in patients with low MBL levels (P = 0.016). MBL levels >400 ng/ml were associated with a hazard ratio of 6.28 for patient death (95% confidence interval 1.8 to 20.3; P = 0.003). Accordingly, survival was significantly better in recipients with MBL gene polymorphisms associated with low MBL levels. These findings identify MBL as a potential risk factor for graft and patient survival in SPKT. It is hypothesized that MBL contributes to the pathogenesis of inflammation-induced vascular damage both in the transplanted organs and in the recipient's native blood vessels.