Mannose-binding Lectin Deficiency Research Articles

Humoral and cellular response to the third COVID-19 vaccination in patients with inborn errors of immunity or mannose-binding lectin deficiency : Aprospective controlled open-label trial.

Impaired immune response to COVID-19 (coronavirus disease 2019) vaccination has been reported in patients with inborn errors of immunity (IEI). Repetitive vaccinations are recommended for this vulnerable group. Due to the high diversity within IEI patients, additional safety and immunogenicity data are needed to better understand these aspects especially in less common immunodeficiency syndromes. In this prospective open-label clinical trial, we assessed the humoral immune response and the T‑cell response in patients with IEI or severe MBL (mannose-binding lectin) deficiency (IEI/MBLdef) after three vaccinations. A total of 16 patients and 16 matched healthy controls (HC) with suboptimal humoral response defined by anti-SARS-CoV‑2 RBD (severe acute respiratory syndrome coronavirus type 2 receptor binding domain) antibodies below 1500 BAU/ml (binding antibody units per ml) after the second COVID-19 vaccination were enrolled in this study and qualified for athird mRNA vaccine dose. After 4 weeks following vaccination, 100% of HC and 75% of IEI/MBLdef patients exhibited anti-SARS-CoV‑2 RBD antibodies > 1500 BAU/ml, although the difference was not statistically significant (75% vs. 100%; p = 0.109). Although post-vaccination IEI/MBLdef patients demonstrated significantly increased anti-SARS-CoV‑2 RBD antibodies and neutralizing antibodies compared to baseline, these responses were significantly lower in IEI/MBLdef patients compared to HCs. Notably, the third vaccination augmented the cellular immune response to both wild-type and omicron peptide stimulation. No serious adverse events were reported within the 4‑week follow-up period and, importantly, vaccination had little to no effect on the long-term disease activity and fatigue. This trial strongly supports the recommendation of repeated COVID-19vaccinations for patients suffering from immunodeficiencies, especially when they exhibit an initially limited response to the vaccine.

Distribution of polymorphic variants of the mannose-binding lectin gene (MBL2) in children with mild and severe asthma

Asthma is one of the most common inflammatory diseases in the world. One of the factors in the development of this disease is a low concentration of mannose-binding lectin (MBL), encoded by the MBL2 gene. Purpose. To study the distribution of genotypes and alleles of polymorphic variants of the MBL2 gene in children with asthma. Material and methods. The study included children with diagnosed bronchial asthma (n=400) (Krasnoyarsk). The control group consisted of children comparable in gender and age to the patients (n=229) and newborns (n=302). GINA-202 guidelines were used to determine the severity of the disease. Results. Statistically significant differences were identified for polymorphisms localized in the first exon of the gene – rs1800450 and rs1800451. A low occurrence of the BB rs1800450 genotype in sick and healthy children was revealed, which may be associated with early mortality or disability due to severe infections with severe MBL deficiency. Homozygotes for the mutant allele C of the rs1800451 MBL2 polymorphism were not found in any of the comparison groups, which indicates a rare distribution of this allele in Caucasian populations. Conclusion. The present study showed that polymorphisms in the MBL2 gene play a predisposing role in the development of diseases of the bronchopulmonary system using the example of asthma.

Mannose-binding lectin gene sequence data in Kelantan population.

The human mannose-binding lectin (MBL) gene encodes a polymorphic protein that plays a crucial role in the innate immune response. Human MBL deficiency is associated with immunodeficiencies, and its variants have been linked to autoimmune and infectious diseases. Despite this significance, gene studies concerning MBL sequencing are uncommon in Malaysia. Therefore, we aimed to preliminary described the human MBL sequencing dataset based on the Kelantan population. Blood samples were collected from 30 unrelated individuals and underwent DNA extraction, genotyping, and sequencing. The sequencing data generated 886 bp, which were deposited in GenBank (ON619541-ON619546). Allelic variants were identified and translated into six MBL haplotypes: HYPA, HYPB, LYPB, LXPB, HXPA, and LXPA. An evolutionary tree was constructed using the haplotype sequences. These findings contribute to the expansion of MBL information within the country, providing a valuable baseline for future research exploring the association between the gene and targeted diseases.

Clinical exome sequencing elucidates underlying cause of death in sudden unexpected death of infants: two case reports

Sudden unexpected death in infants (SUDI) is a traumatic event for families, and unfortunately its occurrence remains high in many parts of the world. Whilst cause of death is resolved for most cases, others remain undetermined following postmortem investigations. There has been a recognition of the role of genetic testing in unexplained cases, where previous studies have demonstrated the resolution of cases through DNA analyses. Here we present two case reports of SUDI cases admitted to Salt River Mortuary, South Africa, and show that underlying causes of death were determined for both infants using clinical exome sequencing. The first infant was heterozygous for a variant (rs148175795) in COL6A3, which suggested a bronchopulmonary dysplasia phenotype. This hypothesis led to finding of a second candidate variant in DMP1 (rs142880465), which may contribute towards a digenic/polygenic mechanism of a more severe phenotype. Histological analysis of retained tissue sections showed an asphyxial mechanism of death, where bronchiolar muscle weakness from an underlying bronchopulmonary dysplasia may have contributed to the asphyxia by affecting respiration. In the second infant, a homozygous variant (rs201340753) was identified in MASP1, which was heterozygous in each parent, highlighting the value of including parental DNA in genetic studies. Whilst mannose-binding lectin deficiency could not be assessed, it is plausible that this variant may have acted in combination with other risk factors within the triple-risk model to result in sudden death. These results may have genetic implications for family members, and represent possible new candidate variants for molecular autopsies.

Mannose binding lectin deficiency and COVID-19 rates of thrombosis and mortality: Partial protection by immunodeficiency

Objective: The purpose of this study is to determine the effects of COVID-19 infection on individuals with mannose binding lectin deficiency. Methods: An electronic medical records search was conducted for MBL deficiency and COVID-19 positive tests from March 2020-August 2022. Individualized chart analysis was conducted and statistical analysis was performed. Results: Thirty-three people in WVU medicine health system carry a diagnosis of mannose binding lectin deficiency and were diagnosed with COVID-19. The mean age of this cohort was 41 years. Seven individuals had severe enough symptoms to lead to an emergency department visit. One person was hospitalized. MBL deficient individuals had 7 times the odds of hospitalization ( p = .1506, OR 7.06 (CI 1.117-44.52)) compared to the general public. There was zero mortality among the MBL deficient population. None of the patients reported thrombosis or blood clots. Conclusion: This retrospective cross-sectional analysis of those with known MBL deficiency and COVID-19 infection suggest a lower risk of fatalities and thrombotic events in this cohort. There was however a higher odds ratio of hospitalization compared to the general public, although this was not statistically significant.

Characterization of Mannose Binding Lectin (MBL) Levels in Type-2 Diabetes Mellitus Patients Amongst Pakistani Population

Introduction: Mannose Binding Lectin (MBL) is a pattern recognizing molecule in the Lectin complement pathway and acts by activating the complement cascade via binding with ligands. There is evidence of increased autoreactivity of Mannose Binding Lectin in various diseases especially diabetes. MBL deficiency can reduce pathogen clearance and impair atherogenic lipoprotein removal whereas higher levels are associated with exaggerated immune response due to complement activation in the presence of hyperglycemia.
 Aims & Objectives: This study aims to find out the association of MBL (Mannose Binding Lectin) with different clinical parameters in healthy controls and type 2 DM patients to predict disease outcome in type 2 diabetics. Mean level of MBL in type 2 diabetics and healthy population will be compared to characterize MBL levels amongst diabetics helping the clinicians to stratify patients according to disease severity.
 Place and duration of study: It was a cross sectional analytical study conducted at Chughtai Institute of Pathology from July 2019 to January 2020 on samples collected nationwide at Chughtai Lab collection centres.
 Material & Methods: We selected 300 adult male and females in this study after taking informed consent based on strict inclusion and exclusion criteria. Of these 200 were known cases of type 2 diabetes mellitus and 100 healthy controls. .Fasting blood samples were drawn from both groups were analyzed for hs-CRP, HbA1c, creatinine, Total Cholesterol, Alanine amino transfer as (ALT), HDL-Cholesterol, LDL-Cholesterol, Glucose, Triglyceride, and Mannose Binding lectin. eGFR (Estimated Glomerular Filtration rate) was calculated for each patient and control. Data was analyzed via Graph Pad Prism 5 and SPSS version 23.0, p value ? 0.05 was taken as significant.
 Results: Mean age of the participants was 47.9 years in diabetic group and 39.3 years in healthy controls. The healthy population had a mean MBL level of 110.1 (SD±3.94) pg/ml and mean MBL level of diabetic group was 197.9 (SD±12.84) pg/ml (p<0.05). No differences in MBL levels were detected based on gender distribution. There was a significant difference among HbA1c, LDL-C, HDL-C, Fasting Glucose, TG, creatinine and eGFR amongst the diabetic and the healthy group (p<0.05). There was a negative correlation between MBL levels and plasma glucose and a positive correlation between the former and HDL-C in the healthy controls. In diabetic patients having MBL above 178pg/ml, a positive correlation of HbA1C with MBL was found. CRP in the healthy population resembled levels in patients with elevated MBL and the ratio Trig/HDL was higher in this subgroup having a positive correlation with MBL.
 Conclusion: MBL plays a role in pathophysiology of diabetes mellitus and elevated MBL having positive correlation with HbA1c might show association of glycemic control with the biomarker levels. A direct relationship of MBL with development of cardiovascular complications in type 2 diabetics was suggested by a positive association of MBL with TG to HDL-C ratio.

5588568 ASSOCIATION OF MANNOSE-BINDING LECTIN SERUM LEVEL AND PROMOTER GENE VARIANTS RS7096206 AND RS10031251 WITH FREQUENCY OF VASO-OCCLUSIVE EVENTS IN SICKLE CELL DISEASE PATIENTS; AN EGYPTIAN CROSS-SECTIONAL STUDY

Background: Sickle cell disease (SCD) is a genetic blood disorder involving hemoglobin alterations, in addition to endothelial adhesion, thrombosis and inflammation. Low serum Mannose-binding lectin (MBL) levels can enhance SCD-related blood vessel inflammation as well as reduction of phagocytic activity, leading to sickled erythrocyte accumulation on vessel walls and impaired ability to combat infections. This may contribute to the vaso-occlusive (VOC) episodes. Aim: This work aimed to investigate serum MBL level and MBL promoter gene variants distribution among a cohort of Egyptian SCD patients and to describe their association with VOC events frequencies in the studied patients. Methods: This cross-sectional study included 88 steady-state Egyptian SCD patients aged 6-18 years diagnosed and followed up at Pediatric Hematology Unit, Cairo University Children Hospital. Informed consent was obtained willingly from all subjects or their guardians before enrolment in the study. MBL promoter (-221) (rs7096206) X/Y and (-550) (rs10031251) H/L gene variants were studied by Polymerase Chain Reaction- Restriction Fragment Length Polymorphism (PCR-RFLP) technique. Serum MBL level was assayed by ELISA technique with values <500ng/ml considered deficient. Results: The median serum MBL level in SCD patients was 130.9 ng/ml (IQR 71.2-323.9 ng/ml). Patients with serum MBL levels <500ng/ml were significantly older, had longer disease duration and higher rate of VOCs per year, VOCs per lifetime and a higher VOC index (p= 0.039, 0.034, 0.047, 0.040 and 0.008 respectively). Levels <500ng/ml predominated in SS (89.4%) than Sβ groups (70%) (p= 0.023) and in patients with high frequency of VOCs (91.4%) (p=0.008). Serum MBL level correlated negatively with patients’ age, disease duration, hydroxyurea total treatment duration, blood transfusions per lifetime and steady-state HbS level (p= <0.001, <0.001, 0.011, 0.014, 0.031 respectively) but correlated positively with steady-state HbF level (p=0.002). MBL (-221) X/Y both alleles were more associated with (H) allele of MBL (-550) than with L allele (p=0.048), however, with no statistically significant genotype distribution between the studied variants. There was no statistically significant difference in genotype distribution or allele frequencies between MBL (-221) and MBL (-550) in SCD patients regarding serum MBL level, sickle cell type (SS and Sβ), VOCs frequencies or disease severity classes. Conclusion: Serum MBL level rather than studied MBL gene variants is more likely to contribute to the clinical outcomes of SCD; patients with lower MBL levels had a higher rate of VOC per year, per lifetime and a higher VOC index. Meanwhile, the variant genotypes and alleles of the studied MBL promotor gene variants were not associated with MBL deficiency, VOCs, infection events, and disease severity.Further studies to investigate other polymorphisms in MBL gene; MBL exon-1 (codons 52,54 and 57) are recommended. Keywords: MBL, Polymorphism, Sickle cell disease, Vaso-occlusive crises, Egypt

Respiratory Outcomes at 5-Year Follow-Up in Children with Mannose-Binding Lectin Deficiency: A Retrospective Cohort Study.

Mannose-binding lectin deficiency may predispose children to having increased infection susceptibility. However, there is no conclusive evidence that mannose-binding lectin deficiency is associated with adverse respiratory consequences in children. We aimed to evaluate the effects of mannose-binding lectin deficiency (defined as a level of less than 0.6 mg/L) on clinical, radiological, and microbiological characteristics in children presenting with troublesome respiratory symptoms, as compared to those who are mannosebinding lectin-sufficient. We conducted a retrospective cohort study to investigate the association between mannose-binding lectin deficiency and respiratory outcomes in children over a period of 10 years in a large teaching hospital. Children presenting with frequent or persistent respiratory symptoms such as a chronic wet cough lasting more than 4 weeks, recurrent lower respiratory tract infections (≥4 infections in a year), or severe respiratory tract infections requiring admission to intensive care or to high dependency unit were included in the study. The study showed no significant difference in clinical outcomes with mannose-binding lectin deficiency and sufficiency. Thirty-two percent of children with mannose-binding lectin deficiency and 30% of those with mannose-binding lectin sufficiency had positive respiratory microbiology. Twenty-three percent of children with mannose-binding lectin deficiency and 24% of those with mannose-binding lectin sufficiency had radiological changes on plain radiographs; also the prevalence of bronchiectasis was similar in both groups. The rates of admission to pediatric intensive care unit were comparable in the 2 groups. Children with mannose-binding lectin deficiency and sufficiency showed similar clinical, radiological, and microbiological characteristics. Our study suggests that there are no childhood adverse respiratory consequences with mannose-binding lectin deficiency.

Role of Mannose-binding Lectin and Association with Microbial Sensitization in a Cohort of Patients with Atopic Dermatitis

Atopic dermatitis is a relapsing inflammatory skin condition, in which bacteria, fungi and viruses may colonize the skin and aggravate the condition. Mannose-binding lectin is part of the innate immune system. Polymorphism in the mannose-binding lectin gene can result in deficiency of mannose-binding lectin, which may affect defence against microbes. The aim of this study was to investigate whether polymorphisms in the mannose-binding lectin gene affect the extent of sensitization to common skin microbes, the skin barrier function, or the severity of the disease in a cohort of patients with atopic dermatitis. Genetic testing of mannose-binding lectin polymorphism was performed in 60 patients with atopic dermatitis. The disease severity, skin barrier function, and serum levels of specific immunoglobulin E against skin microbes were measured. In patients with low mannose-binding lectin genotype (group 1) 6 of 8 (75%) were sensitized to Candida albicans, compared to 14 of 22 (63.6%) patients with intermediate mannose-binding genotype (group 2) and 10 of 30 (33.3%) patients with high mannose-binding genotype (group 3). Group 1 (low mannose-binding lectin) was more likely to be sensitized to Candida albicans compared with group 3 (high mannose-binding lectin) (odds ratio 6.34, p-value 0.045). In this cohort of patients with atopic dermatitis, mannose-binding lectin deficiency was associated with increased sensitization to Candida albicans.

Analysis of Mannose-Binding Lectin Protein Levels and their MIC Profile in Patients with Dermatophytosis.

Analysis of Mannose-Binding Lectin Protein Levels and their MIC Profile in Patients with Dermatophytosis.

"THE RISK FACTORS RESPONSIBLE FOR THE OCCURRENCE OF PNEUMOCYSTIS PNEUMONIA: NARRATIVE REVIEW"

"Introduction: Pneumocystis jirovecii is a fungal pathogen that causes a serious infection called Pneumocystis pneumonia - abbreviated PCP - in people with an immunosuppression condition (e.g.: HIV infection, cancer, organ transplant, inflammatory or autoimmune diseases, treatment with immunosuppressants like corticosteroids), with a high mortality rate. Methods: We searched the PubMed database for publications describing risk factors responsible for the occurrence of Pneumocystis pneumonia, without restrictions of country or English language. The following search terms were used: ((""Pneumocystis""[Mesh]) AND ""Pneumonia, Pneumocystis""[Mesh]) AND ""Risk Factors""[Mesh], for a period of six years, between 2017 and 2022. Data on the type of study and clinical characteristics of the infection caused by Pneumocystis jirovecii in immunodepressed and immunocompetent patients have been extracted. We identified 41 articles, of which 11 have been considered as relevant and are the basis of the present analysis according to our inclusion criteria. Conclusions: The review of the literature to this end shows that patients who have been exposed to the risk factors such as: advanced age with a preponderance in men, nosocomial transmission via human contamination, those with an immunocompromised immune system due to the deficiency of Mannose-binding lectin (MBL) expression and end-stage renal disease disease (ESRD) who do CCRTx, concurrent chemoradiotherapy or RTx, radiotherapy and are treated with immunosuppressive drugs such as: prednisolone (PSL), calcineurin inhibitor, tumor necrosis factor anti-TNF-α, thioprine, mycophenolate mofetil (MMF) and rituximab there is suspicion to developing Pneumocystis pneumonia, should be carefully diagnosed and managed through an appropriate early prophylaxis. In conclusion, in our opinion more deep studies are necessary in this regard."

Evaluation of Immune Dysregulation in an Austrian Patient Cohort Suffering from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a severe multi-systemic disease characterized by debilitating fatigue that is not relieved by rest. The causes of the disease are still largely unexplained, and no causative treatment is currently available. Changes in the immune response are considered as fundamental in the development of ME/CFS. Thus, we aimed to evaluate the immunological profile of ME/CFS patients in a retrospective data analysis. As part of the routine workup for ME/CFS patients, a differential blood count, leukocyte subtyping, and quantification of immunoglobulins and IgG subclasses, as well as a complement analysis, was performed. Out of 262 ME/CFS patients, 64.9% had a reduction or deficiency in at least one of the listed immune parameters. In contrast, 26.3% showed signs of immune activation or inflammation. A total of 17.6% of the ME/CFS patients had an unclassified antibody deficiency, with IgG3 and IgG4 subclass deficiencies as the most common phenotypes. Reduced MBL (mannose-binding lectin) levels were found in 32% of ME/CFS patients, and MBL deficiency in 7%. In summary, the present results confirmed the relevance of immune dysfunction in ME/CFS patients underlining the involvement of a dysfunctional immune response in the disease. Thus, immune parameters are relevant disease biomarkers, which might lead to targeted therapeutic approaches in the future.

Association of mannose-binding lectin, ficolin-2 and immunoglobulin concentrations with future exacerbations in patients with chronic obstructive pulmonary disease: secondary analysis of the randomized controlled REDUCE trial

BackgroundThe innate and adaptive immune system is involved in the airway inflammation associated with acute exacerbations in patients with chronic obstructive pulmonary disease (COPD). We evaluated the association of mannose-binding lectin (MBL), immunoglobulin (Ig) and ficolin-2 concentrations with COPD exacerbations and according to the glucocorticoid treatment duration for an index exacerbation.MethodsPost-hoc analysis of the randomized, double-blind, placebo-controlled REDUCE trial of 5 vs. 14 days of glucocorticoid treatment for an index exacerbation. MBL, ficolin-2 and total IgG/IgA and subclass concentrations were determined in stored samples drawn (n = 178) 30 days after the index exacerbation and associated with the risk of re-exacerbation during a 180-day follow-up period.ResultsIgG and subclass concentrations were significantly lower after 14 days vs. 5 days of glucocorticoid treatment. Patients with higher MBL concentrations were more likely to suffer from a future exacerbation (multivariable hazard ratio 1.03 per 200 ng/ml increase (95% confidence interval (CI) 1.00–1.06), p = 0.048), whereas ficolin-2 and IgG deficiency were not associated. The risk was most pronounced in patients with high MBL concentrations, IgG deficiency and 14 days of glucocorticoid treatment pointing towards an interactive effect of MBL and IgG deficiency in the presence of prolonged glucocorticoid treatment duration [Relative excess risk due to interaction 2.13 (95% CI − 0.41–4.66, p = 0.10)]. IgG concentrations were significantly lower in patients with frequent re-exacerbations (IgG, 7.81 g/L vs. 9.53 g/L, p = 0.03).ConclusionsMBL modified the short-term exacerbation risk after a recent acute exacerbation of COPD, particularly in the setting of concurrent IgG deficiency and recent prolonged systemic glucocorticoid treatment. Ficolin-2 did not emerge as a predictor of a future exacerbation risk.

Genetic Association With Pseudomonas aeruginosa Acquisition in Cystic Fibrosis: Influence of Surfactant Protein D and Mannose-Binding Lectin.

Background: Pseudomonas aeruginosa (PA) infection in cystic fibrosis (CF) is associated with poor prognosis. Surfactant protein-D (SFTPD) and mannose-binding lectin (MBL) play a critical role in innate immunity and response to bacterial infections. We investigated serum levels and genetic variants of SFTPD and MBL in CF patients.Method: Thirty-five Caucasian patients homozygous for ΔF508del were genotyped for functional relevant polymorphisms within MBL2 (promoter−221 Y/X, codons 52, 54, and 57) and SFTPD genes (Met11Thr, Ala160Thr, and Ser270Thr). Serum levels of collectins, clinical characteristics, and PA status were correlated with genetic data.Results: Patients age, gender, and PA status did not affect MBL and SFTPD serum concentrations. MBL concentrations were correlated with MBL haplotypes. Patients with chronic Pseudomonas aeroginosa infection (PAC) and MBL insufficiency had a shorter interval between first PA infection and onset of PAC (0.01 vs. 4.6 years, p < 0.04) as well as a lower median age at transition to PAC (9.8 vs. 16.4 years, p < 0.03) compared to MBL sufficient patients with PAC. SFTPD serum level and FEV1% (Spearman r = −0.41, p < 0.03) showed a negative correlation irrespective of PA infection status. The hazard ratio to PA acquisition was increased in carriers of the SFTPD haplotype 11Thr-160Ala-270Ser compared to carriers of the common 11Met-160Thr-270Ser haplotype [HR 3.0 (95%CI: 1.1–8.6), p < 0.04].Conclusion: MBL insufficiency leads to a shorter interval between first PA infection and onset of chronic infection. Susceptibility to PA acquisition is associated with SFTPD genetic variants with 11Thr-160Ala-270Ser as risk haplotype for early PA infection. This may be due to presence of threonine associated with oligomeric structure of SFTPD and binding ability to bacteria.

The ambiguous role of mannose-binding lectin (MBL) in human immunity.

Mannose-binding lectin (MBL) and lectin complement pathway have become targets of increasing clinical interest. Many aspects of MBL have been recently explored, including the structural properties that allow it to distinguish self from non-self/altered-self structures. Experimental evidences have declared the additional 5′- and 3′-variants that in amalgamation with well-known secretor polymorphisms change MBL function and concentration. Moreover, the current review highlights the differential behavior of MBL on exposure with extra/intracellular pathogens and in autoimmune diseases, stressing the fact that “high MBL levels can increase diseases susceptibility,” a paradox that needs justification. Attributable to these discrepancies, no absolute level of MBL deficiency could be defined so far and thus must be interpreted for specific diseases through case–control population-specific designs. Overall, it is evident that further research is needed about MBL and the lectin pathway of complement. Particularly, the transformative role of MBL over evolution is of interest and its role with regard to pathogenesis of different diseases and potential therapeutic targets within the respective pathways should be further explored. Apart from this, it is necessary to adopt an extensive locus-wide methodology to apprehend the clinical significance of MBL2 polymorphisms in a variety of infectious diseases by the future studies.

A SNaPshot Assay for Determination of the Mannose-Binding Lectin Gene Variants and an Algorithm for Calculation of Haplogenotype Combinations.

Mannose-binding lectin (MBL) deficiency caused by the variability in the MBL2 gene is responsible for the susceptibility to and severity of various infectious and autoimmune diseases. A combination of six single nucleotide polymorphisms (SNPs) has a major impact on MBL levels in circulation. The aim of this study is to design and validate a sensitive and economical method for determining MBL2 haplogenotypes. The SNaPshot assay is designed and optimized to genotype six SNPs (rs1800451, rs1800450, rs5030737, rs7095891, rs7096206, rs11003125) and is validated by comparing results with Sanger sequencing. Additionally, an algorithm for online calculation of haplogenotype combinations from the determined genotypes is developed. Three hundred and twenty-eight DNA samples from healthy individuals from the Czech population are genotyped. Minor allele frequencies (MAFs) in the Czech population are in accordance with those present in the European population. The SNaPshot assay for MBL2 genotyping is a high-throughput, cost-effective technique that can be used in further genetic-association studies or in clinical practice. Moreover, a freely available online application for the calculation of haplogenotypes from SNPs is developed within the scope of this project.

Infections and associated diseases in patients with mannose-binding lectin deficiency, presenting to a tertiary care immunology clinic

Clinical significance of mannose-binding lectin MBL deficiency (MBLd) has been argued. The role of mannose-binding lectin (MBL) as a disease modifier, causing other diseases to present with a more severe phenotype, has been suggested. We conducted a retrospective chart review of patients presenting to a tertiary immunology center with recurrent and/or severe infections. All patients underwent immune evaluation and were found to have undetectable MBL levels (<70ng/ml). Types of infections and associated diseases were recorded. 53 patients with MBLd were identified. Most (47/53) had sinopulmonary infections (47/53) including sinusitis (40/53), viral upper respiratory infections (25/53), bronchitis (19/53), pneumonia (15/53), Streptococcal pharyngitis (9/53), otitis media (9/53). Other infections were skin infections (6/53), sepsis (2/53), meningitis (2/53). Among 33 patients with chronic sinusitis, 15/33 had chronic rhinosinusitis without polyps, 10/33 had aspirin exacerbated respiratory disease (AERD), 7/33 chronic rhinosinusitis with polyps (non AERD), 2/33 had allergic fungal sinusitis. Many were atopic (44/53) with allergic rhinitis (30/44), asthma (25/44), atopic dermatitis (7/44), and food allergy (7/44). Associated immunodeficiencies were (13/53) were with common variable immunodeficiency (7/13), IgG subclass deficiency (2/13), isolated IgM deficiency (2/13), other hypogammaglobulinemia (1/13), specific antibody deficiency (1/13), transient T cell lymphopenia of infancy (1/13). Rheumatologic disease was seen in 14/53 patients, hematologic disease in 8/53 and inflammatory bowel disease in 5/53. Other disease findings included bronchiectasis (8/53). Even in the absence of other immunodeficiency, people with MBLd have recurrent infections, most commonly sinopulmonary. Further research, comparing infections, severity and associated illnesses in those with patients with different MBL levels is warranted to define its clinical significance.

Effect of patient immunodeficiencies on the diagnostic performance of serological assays to detect Aspergillus-specific antibodies in chronic pulmonary aspergillosis

BackgroundPrevalence of chronic pulmonary aspergillosis (CPA) is ~3 million patients worldwide, and detection of Aspergillus-specific antibody is a critical diagnostic component. Some patients with CPA have subtle immune deficits possibly contributing to poor Aspergillus antibody production and false negative results. Materials/methodsWe analyzed patient data from 167 cases of clinically confirmed CPA previously evaluated by ImmunoCAP Aspergillus-specific IgG EIA, Bordier ELISA and LDBio Aspergillus IgG/IgM ICT lateral flow assay, to identify deficiencies in: mannose binding lectin (MBL), IgG, IgA, IgM, IFN gamma, IL12 or IL17 production, and/or low cell marker counts (CD4, CD19, CD56). We defined patients as ‘sero-negative’ if ImmunoCAP Aspergillus IgG was consistently and repeatedly negative (<40 mg A/L). ‘Sero-positive’ was defined as all other CPA cases. ResultsWe found the rate of false negatives by ImmunoCAP Aspergillus IgG EIA (n = 23) to be more prevalent in patients with immunodeficiency markers, especially multiple defects. MBL deficiency combined with low CD19 cells (p < 0.001), pneumococcal antibody levels (p = 0.043), IgM (p = 0.047) or three combined (p = 0.001–0.018) or all four together (p = 0.018) were significant. The performance LDBio Aspergillus IgG/IgM ICT appears to be relatively unaffected by immunodeficiency (92.7% of ImmunoCap sero-negatives were positive). The Bordier assay performed significantly better than the ImmunoCAP assay (P = 0.0016) for sero-negative CPA cases. ConclusionsIn select cases of CPA, ImmunoCAP EIA yields a false negative result, making serological diagnosis difficult. ImmunoCAP false negatives are more prevalent in patients with multiple immunological defects, who may still be positive with the LDBio Aspergillus ICT or Bordier EIA.

THE EFFECTIVENESS OF THERAPY BY CRYOPRESERVED HUMAN PLASMA IN PATIENTS WITH DEFICIENCY OF MANNOSE BINDING LECTIN SUFFERING FROM HERPES VIRUS INFECTION

The aim: To research the effectiveness of cryopreserved blood plasma replacement therapy in patients with primary mannose binding lectin (MBL) deficiency, suffering from chronic active herpes virus infections. Materials and methods: Patients of the study group (SG) n= 36 additionally received cryopreserved blood plasma therapy Octaplas (Octapharma, Switzerland). Patients of the control group (CG) n=36 received only chemotherapy with Valganciclovir 450 mg 2/day per os for 1-3 months. The diagnosis of active herpes virus infection was established by PCR of blood leukocytes. Statistical analysis of the obtained information was processed by the calculation of the chi-square (χ2) Pearson criterion, the odds ratio and the associated 95% confidence interval (95% CI). Results: The adding cryopreserved blood plasma substitute to standard therapy with valganciclovir for the treatment of chronic active herpes virus infection in patients with total serum MBL deficiency below 50 ng/ml, allowed to get more negative PCR results. The effectiveness of combination therapy was 50% higher in carrier of HHV-6 (χ2=8,533 and р=0,004; Yeats correction 6,533 and significance 0,011; OR=11,667 and 95% CI=1,939-70,180) and 43% in carrier of HHV-7 (χ2=8,846 and р=0,003; Yeats correction 7,165 and significance 0,008; OR=6,375 and 95% CI=1,711-23,758), compared with monotherapy. The close association between deficit MBL compensation and the results of antiviral treatment is also reported. The effect of such treatment in patients with chronic EBV infection was less (27%). Conclusions: We assumed, that virostatic effect of valganciclovir is increased by MBL-mediated clearance of blood serum from viral particles.

Mannose-binding lectin serum levels and (Gly54asp) gene polymorphism in recurrent aphthous stomatitis: A case-control study.

Objectives: Dysregulation of the immune response appears to play a significant role in recurrent aphthous stomatitis (RAS) development. The main objective of this case–control study is to investigate the blood levels of mannose-binding lectin (MBL) and the frequency of the MBL2 gene (gly54asp) polymorphism in RAS patients, including 40 RAS patients and 40 healthy controls. Methods: Serum MBL levels were determined by ELISA, while the PCR-restriction fragment length polymorphism was used in MBL2 genotyping. Results: The median serum MBL level was significantly lower in the RAS group than in the control group (975 ng/mL (545–1320) vs. 1760 ng/mL (1254–2134); p≤ 0.001). The MBL levels were significantly lower in the BB genotype, whereas they were significantly higher in the wild type AA with a median of 525 and 1340 ng/mL, respectively (p =0.005). The B allele was expressed in significantly higher percentages of RAS patients than in controls. There was no significant association between MBL serum levels (p=0.685) or MBL2 codon 54 genotypes (p=0.382) with the type of ulcers. Conclusion: There was an association between low MBL serum levels and the variant allele B of the MBL2 (gly54asp) gene, and the susceptibility to RAS. As a result, potential novel therapeutic options for RAS patients with MBL deficiency should be investigated.