Comparison of real-time quantitative PCR and two digital PCR platforms to detect copy number variation in FCGR3B

The importance of structural genetic variants, such as copy number variations (CNVs), in modulating human disease is being increasingly recognized. Several clinical conditions require investigation of human neutrophil antigen (HNA-1), which is encoded by the Fc gamma receptor IIIb gene (FCGR3B), including suspicion of neutropenia, infections, and proactive testing of blood component donors to reduce the potential risk in transfusion. In this study, we compared real-time quantitative polymerase chain reaction (qPCR) with two digital PCR (dPCR) platforms, namely droplet digital PCR and an array-based platform, to determine copy numbers (CNs) in FCGR3B. We initially tested 400 anonymous blood donors with qPCR using a commercially available TaqMan probe assay (Applied Biosystems) on a Quant Studio 12 Flex. CNs was determined for all 400 tested individuals with CNs ranging from zero to four. Zero copies were detected in 0.2% (1/400), one copy was detected in 3.8% (15/400), two copies were detected in 87.8% (351/400), three copies were detected in 8.0% (32/400), and four copies were detected in 0.2% (1/400) of tested individuals. From this cohort, we selected 32 donors with CNs from zero to four for analyses with Digital Real-Time PCR (dPCR) using Lab on an array (LOAA) on an On-Point analyzer from Optolane Technologies Inc. and the Droplet Digital PCR (ddPCR) platform from Bio-Rad Laboratories. We compared the obtained CNs of FCGR3B on the three platforms and found full concordance between the CNs obtained. We therefore conclude that all three platforms can be used for quantification of CNs for FCGR3B, and although dPCR has some advantages over qPCR, it was not necessary for reliably estimating CNs of the FCGR3B gene.

High-resolution HLA genotyping identifies risk alleles in both class I and II for primary autoimmune neutropenia in early childhood in a Danish cohort

HLA studies in patients with autoimmune neutropenia (AIN) have shown very consistent results for the association with HLA class II alleles at low resolution. This study aimed to examine the association of both HLA class I and class II at high resolution to clarify the contribution of risk alleles to the disease. A total of 107 AIN patients were genotyped for six loci of HLA class I (HLA-A, -B and -C) and class II (HLA-DRB1, -DQB1, and -DPB1) genes by a high-resolution (3-field, 6-digit) analysis and compared with HLA typing of 1000 healthy controls. Compared with the controls, the allele frequencies were significantly higher in AIN patients for A*02:17:01G, C*01:02:01G, DRB1*10:01:01G, DRB1*14:01:01G, DRB1*16:01:01G, DQB1*05:02:01G, and DQB1*05:03:01G but lower significant for C*03:04:01G, DRB1*04:01:01G, DRB1*13:02:01G, DQB1*03:02:01G, and DQB1*06:04:01G. Frequently associated two-locus haplotypes were found to be DRB1*10:01:01G-DQB1*05:01:01G and DRB1*16:01:01G-DQB1*05:02:01G, while the S2 (Q- or D-KRAA) shared epitope (SE) was associated with lower risk. A unique association with HLA alleles was observed between patients with specific anti-HNA-1a antibodies and broad-reacting anti-FcγRIIIb. Anti-HNA-1a antibody-positive patients were associated with C*01:02:01G, DRB1*01:01:01G, DRB1*16:01:01G, DQB1*05:01:01G, DQB1*05:02:01G, DQB1*06:04:01G, and DPB1*10:01:01G; the two-locus haplotypes DRB1*01:01:01G-DQB1*05:01:01G and DRB1*16:01:01G-DQB1*05:02:01G; and the S3P (Q- or R-RRAA) SE. Anti-FcγRIIIb antibody-positive patients were associated with the alleles A*02:17:01G, DRB1*10:01:01G, and DQB1*05:02:01G; the haplotypes DRB1*10:01:01G-DQB1*05:01:01G and DRB1*11:01:02G-DQB1*05:02:01G; and the S3D (DRRAA) SE. The different associations regarding FcγRIIIb antibody specificities could indicate disease heterogeneity.

Angiogenic factors and the lectin pathway of complement in women with secondary recurrent pregnancy loss

The poor remodeling of placental spiral arteries seen in preeclampsia is also discussed to contribute to recurrent pregnancy loss (RPL) preceded by abnormal angiogenesis and excessive complement activation. Low levels of Mannose-binding-lectin (MBL), a pattern recognition molecule (PRM) of the lectin pathway, have been found in women with RPL. We propose that pregnancy loss is connected to defective angiogenesis with reperfusion damage in the placenta and decreased levels of PRM in the lectin pathway in women with RPL. In this cohort study, we investigate the angiogenic factors and the lectin complement pathway in early pregnancy and their time-dependent relationship with pregnancy outcomes in 76 women with secondary RPL (sRPL) who have at least four prior pregnancy losses and a live birth. We evaluated levels of Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2), Vascular Endothelial Growth Factor (VEGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and the PRMs, MBL, ficolin-1, -2, -3 and an additional soluble PRM, Pentraxin-3, during the 5th, 6th, and 7th gestational weeks. Our results showed that, compared to live births, pregnancies that ended in loss were associated with elevated VEGF levels and decreased levels of the Ang-2/Ang-1 ratio. Also, increasing levels of ficolin-2 were significantly associated with pregnancy loss, with MBL showing no association. Our research suggests that women with sRPL may have inadequate placentation with impaired angiogenesis in pregnancies ending in a loss.

Characterization of circulating extracellular traps and immune responses to citrullinated LL37 in psoriasis

Background

The DNA-binding peptide LL37 is a suspected autoantigen in psoriasis. It can be found in neutrophil extracellular traps (NETs) which have been suggested to play a role in the pathogenesis of the disease. Citrullination, the conversion of peptidyl-arginine into peptidyl-citrulline, can be implicated in the formation of NETs. We hypothesized that citrullination increases LL37 immunogenicity and that NETs are a source of LL37.

Objectives

We aimed to characterize cytokine responses of B cells and T cells to native and citrullinated LL37 (citLL37) and determine the prevalence and composition of circulating NETs in patients with psoriasis and healthy blood donors (HDs).

Methods

Mononuclear cells (MNCs) and serum were isolated from 20 HDs and 20 patients with psoriasis. The MNCs were stimulated with native LL37 and citLL37 and the proportion of cytokine-positive B cells and T cells was determined by flow cytometry. Circulating antibodies against native LL37 and citLL37 as well as circulating NETs were measured by ELISA, as was the content of LL37, citLL37, and IgG in the NETs.

Results

CitLL37, but not native LL37, induced IFN-γ-production by T cells and B cells from psoriasis patients, as well as IL-10-production by the patients' CD4+ T cells. Serum from 40% of patients and 55% of HDs contained circulating NETs, of which 63% and 27%, respectively, contained LL37. Only two patients had NETs containing citLL37 and IgG antibodies were found in NETs from three patients and one HD. Post-hoc analysis of the cytokines produced by B cells and T cells after stimulation with citLL37 revealed two clusters of patients consisting of 10 high-responders and 9 low-responders. The high-responders were those that had circulating NETs in combination with an earlier age of onset of the disease.

Conclusion

Citrullinated but not native LL37 elicits IFN-γ-responses by T cells and B cells from psoriasis patients, particularly those with circulating NETs and early disease onset, suggesting a role of citLL37 as an autoantigen in this subgroup of patients.

Genetic variations in low-to-medium-affinity Fcγ receptors and autoimmune neutropenia in early childhood in a Danish cohort

Autoimmune neutropenia (AIN) in early childhood is caused by autoantibodies directed against antigens on the neutrophil membrane and is a frequent cause of neutropenia in children. Association of AIN with Fcγ receptor (FCGR) 3B variants is well described. In this study, we investigate genetic variations in the FCGR locus and copy number variation of FCGR3B. A total of 130 antibody-positive AIN patients, 64 with specific anti-HNA-1a antibodies and 66 with broad-reacting anti-FcγRIIIb antibodies, were genotyped with a multiplex ligation probe assay and compared with healthy controls. Positive findings were confirmed with real-time q-PCR. We determined copy numbers of the FCGR2 and FCGR3 genes and the following SNPs: FCGR2A Q62W (rs201218628), FCGR2A H166R (rs1801274), FCGR2B I232T (rs1050501), FCGR3A V176F (rs396991), haplotypes for FCGR2B/C promoters (rs3219018/rs780467580), FCGR2C STOP/ORF and HNA-1 genotypes in FCGR3B (rs447536, rs448740, rs52820103, rs428888 and rs2290834). Generally, associations were antibody specific, with all associations being representative of the anti-HNA-1a-positive group, while the only association found in the anti-FcγRIIIb group was with the HNA-1 genotype. An increased risk of AIN was observed for patients with one copy of FCGR3B; the HNA genotypes HNA-1a, HNA-1aa or HNA-1aac; the FCGR2A 166H and FCGR2B 232I variations; and no copies of FCGR2B 2B.4. A decreased risk was observed for HNA genotype HNA-1bb; FCGR2A 166R; FCGR2B 232T; and one copy of FCGR2B promoter 2B.4. We conclude that in our Danish cohort, there was a strong association between variation in the FCGR locus and AIN. The findings of different genetic associations between autoantibody groups could indicate the presence of two different disease entities and disease heterogeneity.

Maternal carriage of H-Y restricting HLA class II alleles is a negative prognostic factor for women with recurrent pregnancy loss after birth of a boy

Immune system aberrations are suggested to be an important factor in the pathophysiology of unexplained secondary recurrent pregnancy loss (sRPL). The objective was to investigate if the sex ratio of the firstborn child in sRPL patients differs from the background population and whether the sex of the firstborn child has a negative impact on the pregnancy prognosis alone and/or in combination with carriage of male-specific minor histocompatibility (H-Y) restricting HLA class II alleles. From January 2016 to October 2022, 582 patients with unexplained RPL were admitted to the RPL Center of Western Denmark and continuously followed-up. HLA-DRB1 and -DQB1 typing was performed as part of the routine diagnostic work-up. In sRPL patients, a history of a firstborn boy was significantly more frequent than in the Danish background population and was associated with significantly lower odds of a successful reproductive outcome in the first pregnancy after admission compared to a firstborn girl (OR=0.41, 95% CI: 0.20-0.83, p = 0.014). The odds of a successful reproductive outcome were enhanced in patients carrying ≥ 1 H-Y-restricting HLA class II alleles with a first-born girl compared to a firstborn boy (OR=3.33, 95% CI: 1.40-7.88, p = 0.005), while no difference in successful reproductive outcome was seen in sRPL patients not carrying these alleles (OR=1.20, 95% CI: 0.33-4.43, p = 0.781). The sex ratio of children born after RPL was similar to the Danish background population. These findings confirm previous findings and suggests that a harmful immune response triggered by H-Y-antigen exposure during a previous pregnancy in preconditioned women may cause sRPL.

Campylobacter concisus from chronic inflammatory bowel diseases stimulates IL-8 production in HT-29 cells

The emerging pathogen Campylobacter concisus has been isolated from patients with gastrointestinal diseases; however, it is also present in the gut of healthy individuals. The aim of this study was to compare IL-8 production in HT-29 cells after infection with C. concisus from different gastrointestinal disease phenotypes. Additionally, to investigate whether differentiation of isolates in genomospecies (GS1 and GS2) or presence of the zot gene, encoding the Zot toxin, affects IL-8 production. A total of 37 C. concisus isolates from patients with microscopic colitis (n = 20), ulcerative colitis (n = 5), Crohn's disease (n = 5), diarrhoea (n = 2) and from healthy controls (n = 5) were used. Intestinal HT-29 cells were infected and incubated for 24 h. Supernatants were subsequently removed and analysed for IL-8 by MILLIPLEX. All isolates were able to stimulate IL-8 production and IL-8 levels were higher than in non-infected HT-29 cells. No difference was observed between disease phenotypes or GS1 and GS2, whereas presence of the zot gene showed a tendency towards higher IL-8 production. Further investigations in other inflammatory and physiological models are needed to conclude whether C. concisus strains from different gastrointestinal disease phenotypes differ in pathogenic potential and play a part in gastrointestinal disease.

A combination of the HLA-DRB1*03 phenotype and low plasma mannose-binding lectin predisposes to autoantibody formation in women with recurrent pregnancy loss

Introduction

It is documented that a series of autoantibodies can be detected with increased frequency in women with recurrent pregnancy loss (RPL) and they may impact the pregnancy prognosis negatively. It is unknown whether the autoantibodies per se or the basic immune disturbances underlying autoantibody production, are the reason for this association. Our group has previously found that some genetically determined immunological biomarkers are associated with RPL and the same biomarkers are also in various degrees known to predispose to autoantibody production. The aim of this study was to clarify whether the RPL-associated immunogenetic biomarkers are associated with positivity for three major classes of autoantibodies associated with RPL.

Methods

In 663 patients with RPL in whom we had results for HLA-DRB1 typing and plasma mannose-binding lectin (p-MBL) measurement, it was investigated whether there is a correlation between positivity for the autoantibodies: anticardiolipin antibodies, β2 glycoprotein I antibodies, and lupus anticoagulant (jointly called antiphospholipid antibodies), thyroid-peroxidase antibodies, and antinuclear antibodies and each of the HLA-DRB1 alleles HLA-DRB1*03 or HLA-DRB1*07 either alone or in combination with low p-MBL defined as ≤500 µg/l.

Results

Although slightly higher frequencies of positivity of two or more autoantibodies were seen in patients with either p-MBL ≤500 µg/l or being positive for HLA-DRB1*03, none were significantly associated. However, in patients with the combination of low p-MBL and HLA-DRB1*03, presence of at least one autoantibody was significantly more frequent than in patients with no such combination (OR= 2.4; 95% CI 1.2-5.0, p = 0.01). In an analysis of which autoantibodies were most strongly associated with the low p-MBL/HLA-DRB1*03 combination, antinuclear antibodies were significantly more frequent in these patients (OR 2.0; 95% CI 1.0-3.9, p=0.05) whereas the other autoantibodies were also positively but more weakly associated with this combination.

Discussion

In conclusion, to clarify the pathogenetic background, underlying immunogenetic factors should be examined in autoantibody positive RPL patients (as well as other patients with autoimmune diseases) but the genetic background may be complex.

High MBL-expressing genotypes are associated with deterioration in renal function in type 2 diabetes

Introduction

Accumulating evidence support that mannan-binding lectin (MBL) is a promising prognostic biomarker for risk-stratification of diabetic micro- and macrovascular complications. Serum MBL levels are predominately genetically determined and depend on MBL genotype. However, Type 1 diabetes (T1D) is associated with higher MBL serum levels for a given MBL genotype, but it remains unknown if this is also the case for patients with T2D. In this study, we evaluated the impact of MBL genotypes on renal function trajectories serum MBL levels and compared MBL genotypes in newly diagnosed patients with T2D with age- and sex-matched healthy individuals. Furthermore, we evaluated differences in parameters of insulin resistance within MBL genotypes.

Methods

In a cross-sectional study, we included 100 patients who were recently diagnosed with T2D and 100 age- and sex-matched individuals. We measured serum MBL levels, MBL genotype, standard biochemistry, and DEXA, in all participants. A 5-year clinical follow-up study was conducted, followed by 12-year data on follow-up biochemistry and clinical status for the progression to micro- or macroalbuminuria for the patients with T2D.

Results

We found similar serum MBL levels and distribution of MBL genotypes between T2D patients and healthy individuals. The serum MBL level for a given MBL genotype did not differ between the groups neither at study entry nor at 5-year follow-up. We found that plasma creatinine increased more rapidly in patients with T2D with the high MBL expression genotype than with the medium/low MBL expression genotype over the 12-year follow-up period (p = 0.029). Serum MBL levels did not correlate with diabetes duration nor with HbA1c. Interestingly, serum MBL was inversely correlated with body fat percentage in individuals with high MBL expression genotypes both at study entry (p=0.0005) and 5-years follow-up (p=0.002).

Discussion

Contrary to T1D, T2D is not per se associated with increased MBL serum level for a given MBL genotype or with diabetes duration. Serum MBL was inversely correlated with body fat percentage, and T2D patients with the high MBL expression genotype presented with deterioration of renal function.

Intravenous immunoglobulin and prednisolone to women with unexplained recurrent pregnancy loss after assisted reproductive technology treatment: a protocol for a randomised, double-blind, placebo-controlled trial

INTRODUCTION

Recurrent pregnancy loss (RPL), defined as two or more consecutive pregnancy losses in the first trimester, affects around 5% of fertile women. The underlying causes remain unknown in up to 60% of patients; however, most studies point at an immunological pathology in unexplained RPL, and therefore, an effective treatment may be immunomodulatory. This study aims to evaluate the effect of intravenous immunoglobulin (IVIg) and prednisolone on reproductive outcome and the immune system in women with unexplained RPL undergoing assisted reproductive technology treatment.

METHODS AND ANALYSIS

This randomised, placebo-controlled trial with double-blinded randomisation to two parallel arms evaluate if immunomodulatory (active) treatment is superior to placebo in increasing the chance of ongoing pregnancy assessed at nuchal translucency scan in gestational weeks (GW) 11-13 after embryo transfer (ET) in 74 RPL patients with ≥2 pregnancy losses as its primary objective. The active treatment consists of IVIg (one infusion preferably 1-5 days before ET and in GW 5, 6 and 7) and prednisolone (5 mg/day from first day of menstrual bleeding until ET and 10 mg/day from ET to GW 8+0) while the comparator consists of intravenous human albumin (5%) and placebo tablets. Allocation is concealed for participants, caregivers, and investigators until trial termination and is performed in a 1:1 ratio. The secondary objective is to evaluate treatment safety, and the tertiary objective is exploration of the association between treatment, reproductive outcome after ET, and the lymphocyte subset distribution in peripheral blood collected before and after intravenous infusion(s). Excess biological material is stored in a biobank for future research.

ETHICS AND DISSEMINATION

The North Denmark Region Committee on Health Research Ethics (N-20200066) approved this trial. The results will be published in peer-reviewed scientific journals and presented to relevant patient associations, at relevant academic conferences and to key stakeholders.

TRIAL REGISTRATION NUMBER

NCT04701034.

ABO, secretor, and Lewis carbohydrate histo-blood groups are associated with autoimmune neutropenia of early childhood in Danish patients

Background

Autoimmune neutropenia of early childhood (AIN) is caused by autoantibodies directed against antigens on the neutrophil membrane. The ABO, secretor, and Lewis histo‐blood group systems control the expression of carbohydrate antigens and have previously been linked to autoimmune diseases. We aimed to investigate the association between genotypes and the risk of AIN in Danish patients.

Study Design and Methods

One hundred fifty‐four antibody‐positive AIN patients were included. Controls (n = 400) were healthy unrelated Danish blood donors. Molecular determination of ABO, secretor (FUT2), and Lewis (FUT3) genotypes were determined using real‐time polymerase chain reaction (qPCR) or Sanger sequencing to infer the prevalence of Lewis antigens (Le^a and Le^b) and secretor (SeSe or Sese) or nonsecretor (sese) phenotypes.

Results

Blood type O was more common in controls (46.8%) than in AIN patients (36.4%) (OR = 0.65; p = 0.028). Secretors of H Le^b antigens were less frequent among AIN patients (25.2%) than controls (35.0%) (OR = 0.62; p = 0.037).

Discussion

ABO blood group antigens and the secretion of these antigens are associated with a diagnosis of AIN. The mechanism underlying the association between autoimmunity and interaction among ABO, secretor, and Lewis genotypes has not yet been elucidated, but several studies indicate a connection to the gut microbiota.

The development of an indel panel for microchimerism detection

OBJECTIVES

The aim of the study was to create a simple assay for microchimerism detection independent of sex and without HLA genotyping.

METHODS

The method is based on detection of insertion or deletions utilizing a multiplex PCR followed by fragment analysis by capillary electrophoresis, and probe-based qPCR assays. A total of 192 samples, taken either before pregnancy, during 1st trimester, or either during 2nd trimester or at miscarriage, obtained from a cohort of 97 female patients with either primary or secondary recurrent pregnancy loss, were screened for fetal microchimerism by the indel panel as well as an existing assay based on detection of the Y-chromosome marker; DYS14.

RESULTS

The overall prevalence of DYS14 positive samples was 29% (55/192) whereas 32% (61/192) tested positive by the indel method. There was an overall agreement of 64% (122/192) between the results obtained by the two methods. A Fisher's Exact test showed no statistic significant difference in the prevalence of microchimerism detected by the two methods at any of the three times of sampling. The distribution of the number of positive wells detected by both methods were compared by a Mann-Whitney U test, which showed no statistically significant difference at any of the three times of sampling.

CONCLUSION

The data indicates that microchimerism can be detected efficiently by the indel method. This makes it possible to detect both female and male cells without the need of HLA-genotyping. Furthermore, the indel method has potential to be implemented as a routine analysis. This will remove the sex bias in future explorations of the role microchimerism plays in health and disease.

Plasma level of mannose-binding lectin is associated with the risk of recurrent pregnancy loss but not pregnancy outcome after the diagnosis

STUDY QUESTION

Are low or high plasma mannose-binding lectin (p-MBL) levels associated with recurrent pregnancy loss (RPL) and the reproductive and perinatal outcomes before and after RPL?

SUMMARY ANSWER

The prevalence of low p-MBL levels was significantly higher in RPL patients, while high levels were significantly less prevalent. No association was found between p-MBL level and reproductive and perinatal outcomes before and after RPL.

WHAT IS KNOWN ALREADY

Mannose-binding lectin (MBL) is an important component in the innate immune system. Low p-MBL levels have been associated with RPL, while the correlation with high levels has been poorly studied. Adverse perinatal outcomes are generally more frequent among RPL patients, but reports concerning the association between maternal p-MBL levels and perinatal outcomes, including birth weight (BW) and gestational age (GA), are conflicting.

STUDY DESIGN, SIZE, DURATION

This study was a combined cross-sectional and cohort study of 267 RPL patients admitted to the RPL Center of Western Denmark between January 2016 and March 2020. RPL patients were followed until birth of a liveborn child or until end of follow-up, March 2021. A sample of 185 healthy female blood donors of reproductive age was used as a MBL reference group.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All RPL patients had ≥3 consecutive pregnancy losses, a regular menstrual cycle and no known significant chromosomal or uterine malformations. At the first consultation, routine blood samples including p-MBL measurement and detailed obstetrical and perinatal information were collected. p-MBL levels in RPL patients were compared to the MBL reference group. A logistic regression analysis adjusted for relevant confounders assessed the association between low p-MBL levels and an unsuccessful reproductive outcome in RPL patients in first pregnancy after admission. Perinatal outcomes before and after RPL were compared between RPL subgroups according to low (≤500 µg/l), intermediate (501–3000 µg/l) and high (>3000 µg/l) p-MBL levels.

MAIN RESULTS AND THE ROLE OF CHANCE

Significantly more RPL patients had low p-MBL levels (prevalence proportion ratio (PPR): 1.79, 95% CI: 1.34–2.38) and fewer had high p-MBL levels (PPR: 0.56, 95% CI: 0.40–0.79) compared to the reference group, while the prevalence of intermediate p-MBL level was not different between the groups (PPR: 0.86, 95% CI: 0.69–1.08). In the prospective study, low p-MBL level was not a significant risk factor for a pregnancy loss in the first pregnancy after admission after adjustment for age, BMI and smoking. Neither before nor after the RPL diagnosis were maternal p-MBL levels significantly associated with BW or GA.

LIMITATIONS, REASONS FOR CAUTION

Only 161 (60.3%) patients had given birth after RPL during the follow-up period, which limited the possibility to detect clear associations between p-MBL levels and perinatal outcomes after RPL.

WIDER IMPLICATIONS OF THE FINDINGS

In agreement with several previous studies, low p-MBL levels are strongly associated with RPL, while this study for the first time documents that high levels may play a protective role, which suggests a causal relationship. We suggest that larger prospective studies evaluate the association between p-MBL levels and RPL prognosis.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was received. We acknowledge the Department of Obstetrics and Gynaecology at Aalborg University Hospital for financial support. U.S.K. has reported personal fees from Merck, consulting fees from IBSA Nordic, and a grant from Gedeon Richter, Merck and IBSA Nordic outside of the submitted work.

TRIAL REGISTRATION NUMBER

ID from clinicaltrials.gov is NCT04017754.

Polygenic Risk Score Prediction for Endometriosis

Endometriosis is a major health care challenge because many young women with endometriosis go undetected for an extended period, which may lead to pain sensitization. Clinical tools to better identify candidates for laparoscopy-guided diagnosis are urgently needed. Since endometriosis has a strong genetic component, there is a growing interest in using genetics as part of the clinical risk assessment. The aim of this work was to investigate the discriminative ability of a polygenic risk score (PRS) for endometriosis using three different cohorts: surgically confirmed cases from the Western Danish endometriosis referral Center (249 cases, 348 controls), cases identified from the Danish Twin Registry (DTR) based on ICD-10 codes from the National Patient Registry (140 cases, 316 controls), and replication analysis in the UK Biobank (2,967 cases, 256,222 controls). Patients with adenomyosis from the DTR (25 cases) and from the UK Biobank (1,883 cases) were included for comparison. The PRS was derived from 14 genetic variants identified in a published genome-wide association study with more than 17,000 cases. The PRS was associated with endometriosis in surgically confirmed cases [odds ratio (OR) = 1.59, p = 2.57× 10⁻⁷] and in cases from the DTR biobank (OR = 1.50, p = 0.0001). Combining the two Danish cohorts, each standard deviation increase in PRS was associated with endometriosis (OR = 1.57, p = 2.5× 10⁻¹¹), as well as the major subtypes of endometriosis; ovarian (OR = 1.72, p = 6.7× 10⁻⁵), infiltrating (OR = 1.66, p = 2.7× 10⁻⁹), and peritoneal (OR = 1.51, p = 2.6 × 10⁻³). These findings were replicated in the UK Biobank with a much larger sample size (OR = 1.28, p < 2.2× 10⁻¹⁶). The PRS was not associated with adenomyosis, suggesting that adenomyosis is not driven by the same genetic risk variants as endometriosis. Our results suggest that a PRS captures an increased risk of all types of endometriosis rather than an increased risk for endometriosis in specific locations. Although the discriminative accuracy is not yet sufficient as a stand-alone clinical utility, our data demonstrate that genetics risk variants in form of a simple PRS may add significant new discriminatory value. We suggest that an endometriosis PRS in combination with classical clinical risk factors and symptoms could be an important step in developing an urgently needed endometriosis risk stratification tool.

Pattern Recognition Molecules of Lectin Complement Pathway in Ischemic Stroke

Purpose

The current study aimed to investigate in an Armenian population the levels of pattern recognition molecules (PRMs) of lectin complement pathway (LCP), MBL (mannan-binding lectin) and M-ficolin in plasma in ischemic stroke (IS), and the possible association of 11 single nucleotide polymorphisms (SNPs) in MBL2, FCN1 and FCN2 genes.

Patients and Methods

A total of 122 patients with IS and 150 control subjects were included in this study. Immunofluorometric assays (TRIFMAs) and real-time polymerase chain reactions with TaqMan probes were conducted.

Results

According to the results, the levels of M-ficolin in IS patients are significantly higher than in control subjects, and the MBL2 rs11003125 and rs12780112 SNPs, as well as MBL2 rs12780112*T and FCN1 rs10120023*T minor alleles (MAs) are negatively associated with the risk of IS. Further, MBL2 rs11003125 and rs1800450 SNPs and the carriage of their MAs, as well as FCN1 rs2989727 SNP and the carriage of FCN1 rs10120023*T MA significantly alter plasma MBL and M-ficolin levels in IS patients, respectively. Five common haplotypes in MBL2 gene and three common haplotypes in FCN1 and FCN2 genes were revealed, among which CGTC was negatively associated with IS and decreasing MBL plasma levels in IS.

Conclusion

In conclusion, we suggest that LCP PRMs are associated with the risk of developing IS, and may also participate in pathological events leading to post-ischemic brain damage. This study emphasizes the important contribution of alterations of LCP PRMs on genomic and proteomic levels to the pathomechanisms of ischemic stroke, at least in an Armenian population.

Severe antibody-mediated transfusion-related acute lung injury in an obstetric patient following transfusion of fresh frozen plasma from a non-transfused male blood donor

Transfusion-Related Acute Lung Injury (TRALI) has been associated with neutrophil reacting antibodies in transfused blood products. We report a case of life-threatening TRALI in an obstetric patient triggered by transfusion from a non-transfused male blood donor. A residual risk of TRALI exist, even in a male-only plasma setting.

Mannose-binding lectin and risk of infections in type 2 diabetes: A Danish cohort study

AIMS

In individuals at increased risk of infections, e.g., patients with type 2 diabetes, low MBL may have detrimental effects. We used the Mendelian randomization principle to examine whether genetically low MBL is a risk factor for developing infections in patients with type 2 diabetes.

METHODS

Serum MBL (n = 7305) and MBL genotype (n = 3043) were determined in a nationwide cohort of patients with new type 2 diabetes and up to 8 years follow-up for hospital-treated infections and community-based antimicrobial prescriptions. The associations were examined in spline and Cox regression analyses.

RESULTS

1140 patients (16%) were hospitalized with an infection and 5077 patients (70%) redeemed an antimicrobial prescription. For low (≤100 μg/L) versus intermediate (101-1000 μg/L) serum MBL concentration, the adjusted hazard ratios (aHRs) were 1.13(95% confidence interval, 0.96-1.33) for any hospital-treated infections and 1.19(1.01-1.41) for bacterial infections. Low MBL expression genotype was not associated with risk of any hospital-treated infections except for diarrheal diseases (aHR 2.23[1.04-4.80]). Low MBL expression genotype, but not low serum MBL, was associated with increased risk for antimicrobial prescriptions (aHR 1.18[1.04-2.34] and antibacterial prescriptions 1.20[1.05-1.36]).

CONCLUSIONS

Low MBL is a weak causal risk factor for developing infections in patients with type 2 diabetes.

Association between human leukocyte antigens (HLAs) and human neutrophil antigens (HNAs) and autoimmune neutropenia of infancy in Danish patients

BACKGROUND

Autoimmune neutropenia of infancy (AIN) is a frequent cause of neutropenia in children. The disease is caused by antibodies against epitopes on the immunoglobulin G (IgG) Fc receptor type 3b (FcγIIIb). We investigated the possible association of human neutrophil antigens (HNA), human leukocyte antigen (HLA)-DR, and HLA-DQ alleles with AIN and the association of these genotypes with the presence of autoantibodies.

METHODS

Eighty AIN cases with a median age of 13.5 months were included. Controls were healthy unrelated Danish blood donors. Anti-HNA-1a autoantibodies were detected using a flow cytometric granulocyte immunofluorescence test (Flow-GIFT) with phenotyped donor cells for detection of antibody specificity. Molecular determination of HNA genotypes was determined using real-time polymerase chain reaction (q-PCR). High-resolution HLA-DRB1 and HLA-DQB1 were determined by next-generation sequencing.

RESULTS

Antibodies against HNA-1a were detected in 51% (n = 41) of AIN patients, and anti-HNA-1b was detected in 3% (n = 2) of cases. In 46% of cases, the antibodies were anti-FcγIIIb-reactive. FCGR3B*01+,*02-,*03- was more common (odds ratio, 6.70; P < .0001), and FCGR3B*01-,*02+,*03- was less common (odds ratio, 0.30; P < .0001) among AIN cases. HNA-1a antibodies were significantly more frequent among AIN cases with the FCGR3B*01+,*02-,*03- genotype (odds ratio, 3.86; P < .007). The HLA-DRB1*14 - HLA-DQB1*05:03 haplotype was significantly more common (odds ratio, 7.44; P < .0001) in AIN patients.

CONCLUSION

The HLA haplotype HLA-DRB1*14 - DQB1*05:03 is associated with Danish AIN cases. Among Danish AIN patients, anti-HNA-1a is the most common autoantibody, and the antibody is more common in cases with the FCGR3B*01+,*02-,*03- genotype.

HLA-DRB1 polymorphism in recurrent pregnancy loss: New evidence for an association to HLA-DRB1*07

Many cases of recurrent pregnancy loss (RPL) defined as ≥3 consecutive pregnancy losses are suggested to be caused by an aberrant maternal immune response against the fetus or trophoblast. Human leukocyte antigen (HLA)-DRB1 and -DQB1 polymorphisms are associated with most autoimmune disorders and studies of HLA-DBB1 polymorphism in RPL patients are thus relevant. In previous studies, the HLA-DRB1*03 allele was found with increased prevalence in RPL patients. We wanted to clarify whether HLA-DRB1 alleles indeed were associated with RPL among women of Caucasian descent. A total of 1078 women with unexplained RPL and 2066 bone marrow donors were HLA-DRB1-typed and subsets were also HLA-DQB1 typed. All patients were initially HLA-DRB1-typed by DNA-based low-resolution techniques and subsets of patients and all controls were typed by high-resolution techniques. Among patients, the HLA-DRB1*07 allele frequency was significantly increased compared with controls; OR 1.29 (95 % CI 1.09-1.52), p < 0.0025; after correction for multiple comparisons pc = 0.031. The HLA-DRB1*07/*07 genotype was highly increased in patients with RPL compared with controls: OR 2.27 (1.31-3.93), p = 0.0027. The frequency of the HLA-DRB1*07 phenotype in RPL patients had increased significantly (p = 0.002) in three studies from our group published 1994-2021. The allele frequency of HLA-DRB1*03 was not increased in RPL patients compared with controls; OR 0.96 (0.83-1.12). In conclusion, the previous association between HLA-DRB1*03 and RPL could not be confirmed in our study whereas an association to HLA-DRB1*07 was detected for the first time. Since the latter association is a new finding, it should be confirmed in future studies.

Molecular pathways in patients with systemic lupus erythematosus revealed by gene-centred DNA sequencing

Objectives

Systemic lupus erythematosus (SLE) is an autoimmune disease with extensive heterogeneity in disease presentation between patients, which is likely due to an underlying molecular diversity. Here, we aimed at elucidating the genetic aetiology of SLE from the immunity pathway level to the single variant level, and stratify patients with SLE into distinguishable molecular subgroups, which could inform treatment choices in SLE.

Methods

We undertook a pathway-centred approach, using sequencing of immunological pathway genes. Altogether 1832 candidate genes were analysed in 958 Swedish patients with SLE and 1026 healthy individuals. Aggregate and single variant association testing was performed, and we generated pathway polygenic risk scores (PRS).

Results

We identified two main independent pathways involved in SLE susceptibility: T lymphocyte differentiation and innate immunity, characterised by HLA and interferon, respectively. Pathway PRS defined pathways in individual patients, who on average were positive for seven pathways. We found that SLE organ damage was more pronounced in patients positive for the T or B cell receptor signalling pathways. Further, pathway PRS-based clustering allowed stratification of patients into four groups with different risk score profiles. Studying sets of genes with priors for involvement in SLE, we observed an aggregate common variant contribution to SLE at genes previously reported for monogenic SLE as well as at interferonopathy genes.

Conclusions

Our results show that pathway risk scores have the potential to stratify patients with SLE beyond clinical manifestations into molecular subsets, which may have implications for clinical follow-up and therapy selection.

Mannose-Binding Lectin and Risk of Cardiovascular Events and Mortality in Type 2 Diabetes: A Danish Cohort Study

OBJECTIVE

Mannose-binding lectin (MBL) is linked to risk of cardiovascular disease (CVD) in diabetes, but the nature of the association is unclear. We investigated the association between MBL and the risk of cardiovascular events (CVE) and all-cause mortality in type 2 diabetes.

RESEARCH DESIGN AND METHODS

In a cohort study of 7,588 patients with type 2 diabetes, we measured serum MBL in 7,305 patients and performed MBL expression genotyping in 3,043 patients. We grouped serum MBL and MBL expression genotypes into three categories: low, intermediate, and high. Outcomes were CVE (myocardial infarction, stroke, coronary revascularization, unstable angina, or cardiovascular death) and all-cause mortality. The association with outcomes was examined by spline and Cox regression analyses.

RESULTS

Serum MBL and CVE showed a U-shaped association. Compared with the intermediate serum MBL category, the adjusted hazard ratio (HR) for CVE was 1.82 (95% CI 1.34-2.46) for the low-MBL category and 1.48 (95% CI 1.14-1.92) for the high-MBL category. We found a similar U-shaped association for all-cause mortality, but with lower risk estimates. Compared with the intermediate MBL expression genotype, the adjusted HR for CVE was 1.40 (95% CI 0.87-2.25) for the low-expression genotype and 1.44 (95% CI 1.01-2.06) for the high-expression genotype. MBL expression genotype was not associated with all-cause mortality.

CONCLUSIONS

Both serum MBL and MBL expression genotype showed a U-shaped association with CVE risk in individuals with type 2 diabetes. Our findings suggest that serum MBL is a risk factor for CVD in this population.

Impaired microvascular reactivity after eccentric muscle contractions is not restored by acute ingestion of antioxidants or dietary nitrate

Unaccustomed eccentric exercise leads to impaired microvascular function but the underlying mechanism is unknown. In this study, we evaluated the role of oxidative stress and of nitric oxide (NO) bioavailability. Thirty young men and women performed eccentric contractions of the tibialis anterior (TA) muscle (ECC), with the contralateral leg serving as nonexercising control (CON). Participants were randomized into three groups ingesting an antioxidant cocktail (AO), beetroot juice (BR) or placebo 46 h postexercise. At baseline and 48 h postexercise, hyperemic responses to brief muscle contractions and 5 min of cuff occlusion were assessed bilaterally in the TA muscles using blood oxygen level dependent (BOLD) magnetic resonance imaging. Eccentric contractions resulted in delayed time-to-peak (~22%; P < 0.001), blunted peak (~21%; P < 0.001) and prolonged time-to-half relaxation (~12%, P < 0.001) in the BOLD response to brief contractions, with no effects of AO or BR, and no changes in CON. Postocclusive time-to-peak was also delayed (~54%; P < 0.001) in ECC, with no effects of AO or BR, and no changes in CON. Impaired microvascular reactivity after eccentric contractions is confined to the exercised tissue, and is not restored with acute ingestion of AO or BR. Impairments in microvascular reactivity after unaccustomed eccentric contractions may result from structural changes within the microvasculature that can diminish muscle blood flow regulation during intermittent activities requiring prompt adjustments in oxygen delivery.

AB0202 GENETIC SUSCEPTIBILITY AND PHENOTYPE OF RHEUMATOID ARTHRITIS IN DANISH AND TURKISH PATIENTS

Background:

Previous studies indicate that genetic susceptibility and phenotype of rheumatoid arthritis (RA) differ between the populations.

Objectives:

To compare the clinical, serologic expression and the presence of shared epitopes (SE) of incident RA in two different populations, one from Northern and the other from Southern Europe.

Methods:

Data on incident RA patients fulfilling EULAR/ACR 2010 classifications criteria for RA were collected at Rheumatology Departments in Denmark and Turkey in 2015-2016. Patients were assessed using the same standardized protocol in both populations. SE carrier status were assigned, according to the du Montcel classification based, into six allele groups:S1, S2,S3D,S3PandX, where S2 and S3P are RA risk-enhancing alleles and S1 and S3D are RA protective alleles of the shared epitope(1).

Results:

109 incident RA patients from Denmark and 114 incident RA patients from Turkey were enrolled. Genetic data were available from 87% of the patients.

Table 1.

Characteristics of incident rheumatoid arthritis patients in Denmark and Turkey

Danish patientsn=109Turkish patientsn=114P-valueAge at diagnosis, years60 (49-69)52 (43-64)0.003Female, %64740.12Symptom duration, months7 (4-21)6 (2-22)0.6Smoking status Never smoker, %43440.98 Former smoker, %28310.68 Current smoker, %29250.54VAS pain (0-100 mm)45 (28-66)60 (41-72)0.01VAS fatigue (0-100 mm)51 (29-69)50 (20-70)0.32VAS global, patient (0-100 mm)60 (31-80)60 (41-73)0.77Swollen joint count (0-28)7 (4-11)3 (1-6)<0.00001Tender joint count (0-28)7 (3-11)5 (2-8)0.04HAQ score (0-3)0.75 (0.34-1.25)1.0 (0.25-1.75)0.02DAS284.7 (4.1-5.5)4.3 (3.3-5.2)0.01CRP, mg/l7 (3.0-18.5)8 (3.1-22.6)0.54IgM RF positive, %70660.58ACPA positive, %63750.1

Medians (interquartile range) for continuous variables

VAS – Visual Analog Scale, HAQ - Health Assessment Questionnaire, DAS28 - Disease Activity Score 28 joints, CRP – C-reactive protein, RF – Rheumatoid Factor, ACPA - Anti-Citrullinated Protein Antibodies.

Table 2.

Shared epitope allele carrier frequencies.

AlleleDanish patientsn=98Turkish patientsn=95P-valueS1, % (n)19 (37)22 (42)0,43S2, % (n)26 (51)8 (16)<0,00001S3D, % (n)6 (12)21 (39)0,000029S3P, % (n)27 (52)29 (56)0,52X, % (n)22 (44)19 (37)0,47

We found no associations between the risk-enhancing alleles and the presence of IgM rheumatoid factor or ACPA.

Conclusion:

The Turkish patients were younger and had lower disease activity than Danish at the time of diagnosis. Our study found an enhanced genetic susceptibility to RA in Danish compared to Turkish patients with a higher prevalence of risk-enhancing RA alleles and a lower prevalence of protective alleles.

References:

[1]Tezenas du Montcel S, Michou L, Petit-Teixeira E, Osorio J, Lemaire I, Lasbleiz S, et al. New classification of HLA–DRB1 alleles supports the shared epitope hypothesis of rheumatoid arthritis susceptibility.Arthritis Rheum2005; 52: 1063–8.

Disclosure of Interests:

None declared

Heme oxygenase 1 polymorphism, occupational vapor, gas, dust, and fume exposure and chronic obstructive pulmonary disease in a Danish population-based study

Objectives The number of dinucleotide repeats (GT) _nmodulate expression of heme oxygenase 1 (HMOX1), a stress response gene. Multiple repeats might affect chronic obstructive pulmonary disease (COPD) susceptibility. We aimed to investigate the association of this polymorphism with COPD and its interaction with occupational exposures (vapor, gas, dust, or fumes). Methods This population-based cross-sectional study included 4703 Danes, aged 45-84 years. HMOX1 (GT) _nwas genotyped and grouped as short: ≤26, medium: 27-32 and long: ≥33 alleles. COPD was defined by the lower limit of normal (2.5 ^thFEV ₁/FVC and FEV ₁centiles). Occupational exposure was defined as ever exposed to vapor, gas, dust, or fume in expert-selected jobs. Associations were analyzed by adjusted mixed logistic regression. Results The population included 6% with COPD, 48% who had smoked ≥10 pack-years, and 46% with occupational exposure. HMOX1 was genotyped in 4423 participants. The adjusted odds ratio (OR) for the association between HMOX1 long allele and COPD was 1.75 [95% confidence interval (CI) 1.18-2.60]. An interaction was evident between HMOX1 long allele and occupational exposure, OR 2.38 (95% CI 1.04-5.46), versus HMOX1 short/medium without exposure. Analyses were replicated in another cohort, aged 20-44 years, N=1168, including 3% with COPD, 25% who had smoked ≥10 pack-years and 20% with occupational exposure. No associations were seen between COPD and HMOX1 long allele here. Conclusions Long alleles in HMOX1 alone and in interaction with occupational exposure seem to be associated with COPD. Failure to replicate data may be due to premature age for COPD development and low occupational exposure prevalence. We propose this long allele may be a genetic contributor to the COPD pathogenesis.

The Lectin Pathway of Complement Activation in Patients with Systemic Lupus Erythematosus

OBJECTIVE

The pathogenesis of systemic lupus erythematosus (SLE) involves complement activation. Activation of complement through the classical pathway (CP) is well established. However, complement activation through pattern recognition not only happens through the CP, but also through the lectin pathway (LP). We investigated the hypothesis that the LP is activated in SLE and involved in the pathogenesis of the disease.

METHODS

Using immunoassays developed in-house, we measured concentrations of LP proteins in a cohort of 372 patients with SLE and 170 controls. We estimated complement activation measuring total C3, and investigated whether LP protein concentrations were associated with complement activation and disease activity. Protein changes and disease activity over time were assessed in a cohort of 52 patients with SLE followed with repeated samples over a 5-year period.

RESULTS

Concentrations of LP proteins in SLE were altered compared with controls. The differences observed in LP proteins associated with complement activation were reflected by a decrease in total C3. The pattern recognition molecules (M-ficolin, CL-L1, and CL-K1), the serine protease (MASP-3), and the associated protein (MAp19) displayed a negative correlation with disease activity. Changes in MASP-2 concentrations over time correlated significantly with increased disease activity. Association between active proteinuria and serum concentration was observed for MASP-3 and MAp19.

CONCLUSION

In patients with SLE, we measured specific changes in LP proteins that are associated with complement activation and disease activity, indicating that the LP is activated in patients with SLE. These novel findings substantiate the involvement of the LP in SLE.

Hypothyroid Patients Encoding Combined MCT10 and DIO2 Gene Polymorphisms May Prefer L-T3 + L-T4 Combination Treatment - Data Using a Blind, Randomized, Clinical Study

OBJECTIVES

In previous studies, around half of all hypothyroid patients preferred levo-thyroxine (L-T4) + levo-triiodothyronine (L-T3) combination therapy, 25% preferred T4, and 25% had no preference. The reason for this is yet to be explored.

METHODS

A total of 45 overtly autoimmune, hypothyroid patients - now euthyroid on ≥6 months' L-T4 therapy - participated in a prospective, double-blind, cross-over study. The patients were randomized into 2 groups of either 3 continuous months' L-T4 therapy followed by 3 months' combination therapy or vice versa. In all periods, 50 μg L-T4 was blindly replaced by either (identical) 50 μg L-T4 or by 20 μg T3. L-T4 was hereafter adjusted to obtain normal serum TSH values. We investigated 3 single nucleotide polymorphisms (SNPs) on the type II iodothyronine deiodinase (DIO2) gene (rs225014 (Thr92Ala), rs225015, and rs12885300 (ORFa-Gly3Asp)) and 1 SNP on the cellular membrane transport-facilitating monocarboxylate transporter (MCT10) gene (rs17606253), and asked in which of the 2 treatment periods patients felt better (i.e., which treatment was preferred).

RESULTS

27 out of 45 patients (60%) preferred the combination therapy. Two polymorphisms (rs225014 (DIO2, Thr92Ala) and rs17606253 (MCT10)) were combined yielding 3 groups: none vs. 1 of 2 vs. both SNPs present, and 42 vs. 63 vs. 100% of our patients in the 3 groups preferred the combined treatment (Jongheere-Terpstra trend test, p = 0.009).

CONCLUSION

The present study indicates that the combination of polymorphisms in DIO2 (rs225014) and MCT10 (rs17606253) enhances hypothyroid patients' preference for L-T4 + L-T3 replacement therapy. In the future, combination therapy may be restricted or may be even recommended to individuals harbouring certain polymorphisms.

Plasma levels of MASP-1, MASP-3 and MAp44 in patients with type 2 diabetes: influence of glycaemic control, body composition and polymorphisms in the MASP1 gene

Mounting evidence indicates that adverse activation of the complement system plays a role in the development of diabetic vascular complications. Plasma levels of the complement proteins mannan-binding lectin (MBL) and its associated serine proteases (MASP-1 and MASP-2) are elevated in diabetes. We hypothesized that single nucleotide polymorphisms (SNPs) in the MASP1 gene may contribute to altered plasma levels of the belonging gene products; MASP-1, MASP-3 and mannan-binding lectin-associated protein of 44 kDa (MAp44) in patients with type 2 diabetes. To investigate this, we compared plasma levels of MASP-1, MASP-3 and MAp44 in 100 patients with type 2 diabetes and 100 sex- and age-matched controls. Ten carefully selected SNPs were analysed using TaqMan^® genotyping assay. Additionally, we included a streptozotocin-induced diabetes mouse model to directly examine the effect of inducing diabetes on MASP-1 levels. MASP-1 levels were significantly higher among patients with type 2 diabetes compared with healthy controls (P = 0·017). Five SNPs (rs874603, rs72549254, rs3774275, rs67143992, rs850312) in the MASP1 gene were associated with plasma levels of MASP-1, MASP-3 and MAp44. In the diabetes mouse model, diabetic mice had significantly higher MASP-1 levels than control mice (P = 0·003). In conclusion, MASP-1 levels were higher among patients with type 2 diabetes and diabetic mice. The mechanism behind this increase remains elusive.

Presence of HLA-DR Molecules and HLA-DRB1 mRNA in Circulating CD4(+) T Cells

The human major histocompatibility complex class II isotype HLA-DR is currently used as an activation marker for T cells. However, whether an endogenous protein expression or a molecular acquisition accounts for the presence of HLA-DR on T cells remains undetermined and still controversial. To further characterize this phenomenon, we compared several aspects of the presence of the HLA-DR protein to the presence of associated mRNA (HLA-DRB1), focusing on human T cells from peripheral blood of healthy individuals. Using a flow cytometric approach, we determined that the HLA-DR observed on CD4(+) T cells was almost exclusively cell surface-associated, while for autologous CD19(+) B cells, the protein could be located in the plasma membrane as well as in the cytoplasm. Moreover, negligible expression levels of HLA-DRB1 were found in CD4(+) T cells, using an HLA-DRB1 allele-specific qPCR assay. Finally, the presence of HLA-DR was not confined to activated CD4(+) and CD8(+) T cells, as evaluated by the co-expression of CD25. The functional role of the HLA-DR molecule on T cells remains enigmatic; however, this study presents evidence of fundamental differences for the presence of HLA-DR on T cells from HLA-DR in the context of antigen-presenting cells, which is a well-known phenomenon. Although an inducible endogenous protein expression cannot be excluded for the T cells, our findings suggest that a re-evaluation of the HLA-DR as a T cells activation marker is warranted.

Maternal HY-restricting HLA class II alleles are associated with poor long-term outcome in recurrent pregnancy loss after a boy

PROBLEM

Women with secondary recurrent pregnancy loss (RPL) after a boy have a reduced chance of live birth in the first pregnancy after referral if they carry HY-restricting HLA class II alleles, but long-term chance of live birth is unknown.

METHODS OF STUDY

Live birth was compared for 540 women with unexplained secondary RPL according to firstborn's sex and maternal carriage of HLA-DRB3*03:01, HLA-DQB1*05:01/02, HLA-DRB1*15, and HLA-DRB1*07. The groups were compared by Cox proportional hazard ratios.

RESULTS

For women with at firstborn boy, maternal carriage of HY-restricting HLA class II alleles decreased chance of live birth: 0 vs 1: hazard ratio 0.75 (95% CI 0.55-1.02); 0 vs 2: HR 0.62 (0.40-0.94). Carriage of HY-restricting HLA class II alleles decreased chance of live birth only if the firstborn was a boy: boy vs girl: HR 0.72 (95% CI 0.55-0.98).

CONCLUSION

Maternal carriage of HY-restricting HLA class II alleles decreases long-term chance of live birth in women with RPL after a boy.

Allelic Discrimination by TaqMan-PCR for Genotyping of Human Neutrophil Antigens

Neutrophil antigens are implicated in a variety of clinical conditions, including neonatal immune neutropenia, transfusion-related acute lung injury, refractoriness to granulocyte transfusions, febrile transfusion reactions, and autoimmune neutropenia. In this report, we describe simultaneous genotyping of human neutrophil antigens (HNA)-1, -3, -4, and -5 using PCR with allele-specific TaqMan probes and end-point fluorescence detection, which is a robust, rapid, and reproducible method, allowing for high-throughput genotyping.

Mannose-binding lectin protein and its association to clinical outcomes in COPD: a longitudinal study

BACKGROUND

Functional deficiency of mannose-binding lectin (MBL) may contribute to the pathogenesis of chronic obstructive pulmonary disease. We hypothesized that specific MBL2 gene polymorphisms and circulating MBL protein levels are associated with clinically relevant outcomes in the Predicting Outcome using systemic Markers In Severe Exacerbations of COPD PROMISE-COPD cohort.

METHODS

We followed 277 patients with stable COPD GOLD stage II-IV COPD over a median period of 733 days (IQR 641-767) taking survival as the primary outcome parameter. Patients were dichotomized as frequent (≥ 2 AECOPD/year) or infrequent exacerbators. Serum MBL levels and single nucleotide polymorphisms of the MBL2 gene were assessed at baseline.

RESULTS

The MBL2-HYPD haplotype was significantly more prevalent in frequent exacerbators (OR: 3.33; 95% CI, 1.24-7.14, p = 0.01). The median serum MBL concentration was similar in frequent (607 ng/ml, [IQR; 363.0-896.0 ng/ml]) and infrequent exacerbators (615 ng/ml, [IQR; 371.0-942.0 ng/ml]). Serum MBL was not associated with lung function characteristics or bacterial colonization in sputum. However, high serum MBL at stable state was associated with better survival compared to low MBL (p = 0.046, log rank test).

CONCLUSIONS

In COPD, the HYPD haplotype of MBL2 gene is associated with frequent exacerbations and high serum MBL is linked to increased survival. The PROMISE-COPD study was registered at www.controlled-trials.com under the identifier ISRCTN99586989.

Inheritance of the 8.1 ancestral haplotype in recurrent pregnancy loss

A segment of DNA called the 8.1 ancestral haplotype is hypothesized to cause fetal loss due to a ‘selfish gene’ effect. The hypothesis was not supported, although the haplotype tended to be inherited more often than expected among girls (p=0.11) in a study of 110 mother-child pairs. Further studies are warranted.

Background and objectives: The 8.1 ancestral haplotype (AH) (HLA-A1, C7, B8, C4AQ0, C4B1, DR3, DQ2) is a remarkably long and conserved haplotype in the human major histocompatibility complex. It has been associated with both beneficial and detrimental effects, consistent with antagonistic pleiotropy. It has also been proposed that the survival of long, conserved haplotypes may be due to gestational drive, i.e. selective miscarriage of fetuses who have not inherited the haplotype from a heterozygous mother. Recurrent pregnancy loss (RPL) is defined as three or more consecutive pregnancy losses. The objective was to test the gestational drive theory for the 8.1AH in women with RPL and their live born children.

Methodology: We investigated the inheritance of the 8.1AH from 82 heterozygous RPL women to 110 live born children. All participants were genotyped for HLA-A, -B and -DRB1 in DNA from EDTA-treated blood or buccal swaps. Inheritance was compared with a Mendelian inheritance of 50% using a two-sided exact binomial test.

Results: We found that 55% of the live born children had inherited the 8.1AH, which was not significantly higher than the expected 50% (P = 0.29). Interestingly, we found a non-significant trend toward a higher inheritance of the 8.1AH in girls, 63%, P = 0.11 as opposed to boys, 50%, P = 1.00.

Conclusions and implications: We did not find that the 8.1AH was significantly more often inherited by live born children of 8.1AH heterozygous RPL women. However our data suggest that there may be a sex-specific effect which would be interesting to explore further, both in RPL and in a background population.

Inherited Inflammatory Response Genes Are Associated with B-Cell Non-Hodgkin's Lymphoma Risk and Survival

BACKGROUND

Malignant B-cell clones are affected by both acquired genetic alterations and by inherited genetic variations changing the inflammatory tumour microenvironment.

METHODS

We investigated 50 inflammatory response gene polymorphisms in 355 B-cell non-Hodgkin's lymphoma (B-NHL) samples encompassing 216 diffuse large B cell lymphoma (DLBCL) and 139 follicular lymphoma (FL) and 307 controls. The effect of single genes and haplotypes were investigated and gene-expression analysis was applied for selected genes. Since interaction between risk genes can have a large impact on phenotype, two-way gene-gene interaction analysis was included.

RESULTS

We found inherited SNPs in genes critical for inflammatory pathways; TLR9, IL4, TAP2, IL2RA, FCGR2A, TNFA, IL10RB, GALNT12, IL12A and IL1B were significantly associated with disease risk and SELE, IL1RN, TNFA, TAP2, MBL2, IL5, CX3CR1, CHI3L1 and IL12A were, associated with overall survival (OS) in specific diagnostic entities of B-NHL. We discovered noteworthy interactions between DLBCL risk alleles on IL10 and IL4RA and FL risk alleles on IL4RA and IL4. In relation to OS, a highly significant interaction was observed in DLBCL for IL4RA (rs1805010) * IL10 (rs1800890) (HR = 0.11 (0.02-0.50)). Finally, we explored the expression of risk genes from the gene-gene interaction analysis in normal B-cell subtypes showing a different expression of IL4RA, IL10, IL10RB genes supporting a pathogenetic effect of these interactions in the germinal center.

CONCLUSIONS

The present findings support the importance of inflammatory genes in B-cell lymphomas. We found association between polymorphic sites in inflammatory response genes and risk as well as outcome in B-NHL and suggest an effect of gene-gene interactions during the stepwise oncogenesis.

Increased all-cause mortality in patients with type 1 diabetes and high-expression mannan-binding lectin genotypes: a 12-year follow-up study

OBJECTIVE

Mannan-binding lectin (MBL) is a complement-activating carbohydrate-recognizing molecule associated with diabetic nephropathy. MBL is associated with all-cause mortality in type 2 diabetes, but whether MBL is associated with mortality in type 1 diabetes remains unknown. We therefore aimed to investigate this.

RESEARCH DESIGN AND METHODS

We studied an existing 12-year prospective cohort with type 1 diabetes with 198 patients with diabetic nephropathy (121 men, age 41 years [95% CI 40-42], estimated glomerular filtration rate [eGFR] 67 mL/min/1.73 m(2) [95% CI 63-70]) and 174 normoalbuminuric patients (103 men, age 43 years [95% CI 41-44], eGFR 93 mL/min/1.73 m(2) [95% CI 91-95]). Mortality rates were compared according to the concentration-determining MBL2 genotype or the MBL concentration. Patients were classified as having high or low MBL expression genotypes. The effect of MBL concentration was estimated by comparing patients with MBL concentrations above or below the median.

RESULTS

Ninety-eight patients died during follow-up. The unadjusted hazard ratio (HR) for all-cause mortality was 1.61 (95% CI 1.07-2.43) for patients with high MBL expression genotypes versus patients with low MBL expression genotypes (P = 0.023). All-cause mortality was higher in patients with MBL concentrations above the median than in patients with MBL concentrations below the median (unadjusted HR 1.90 [95% CI 1.26-2.87], P = 0.002).

CONCLUSIONS

High MBL expression genotypes and high MBL concentrations are both associated with increased mortality rates in type 1 diabetes compared with low MBL expression genotypes and low MBL concentrations.

Inherited variation in immune response genes in follicular lymphoma and diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) both depend on immune-mediated survival and proliferation signals from the tumor microenvironment. Inherited genetic variation influences this complex interaction. A total of 89 studies investigating immune-response genes in DLBCL and FL were critically reviewed. Relatively consistent association exists for variation in the tumor necrosis factor alpha (TNFA) and interleukin-10 loci and DLBCL risk; for DLBCL outcome association with the TNFA locus exists. Variations at chromosome 6p31-32 were associated with FL risk. Importantly, individual risk alleles have been shown to interact with each other. We suggest that the pathogenetic impact of polymorphic genes should include gene-gene interaction analysis and should be validated in preclinical model systems of normal B lymphopoiesis and B-cell malignancies. In the future, large cohort studies of interactions and genome-wide association studies are needed to extend the present findings and explore new risk alleles to be studied in preclinical models.

Polymorphisms in Genes Coding for Cytokines, Mannose-Binding Lectin, Collagen Metabolism and Thrombophilia in Women with Cervical Insufficiency

OBJECTIVE

To study the association between cervical insufficiency and single nucleotide polymorphisms in seven genes coding for pro- and anti-inflammatory cytokine-related factors, mannose-binding lectin 2 (MBL2), collagen1α1 (COL1A1), factor II and factor V Leiden genes.

METHODS

In a case-control study, potential maternal biomarkers for cervical insufficiency were investigated in 30 women with a history of second-trimester miscarriage or preterm birth due to cervical insufficiency and in 70 control women.

RESULTS

Homozygous carriers of the interleukin 6 (IL6) -174 genotype GG had an odds ratio (OR) of 3.1 [95% confidence interval (95% CI) 1.3-7.4, p = 0.01] and MBL2 genotypes coding for low or intermediate levels of plasma MBL had an OR of 3.3 (95% CI 1.2-9.0, p = 0.01) for cervical insufficiency compared with controls. Serum MBL levels were lower in women with cervical insufficiency than in controls (median 408 and 1,985 ng/ml, respectively, p < 0.01).

CONCLUSIONS

Single nucleotide polymorphisms in the IL6 gene and the MBL2 gene and low MBL levels related to the latter polymorphism may increase the risk of preterm birth due to cervical insufficiency.

CRP genotype and haplotype associations with serum C-reactive protein level and DAS28 in untreated early rheumatoid arthritis patients

INTRODUCTION

Single-nucleotide polymorphisms (SNPs) in the CRP gene are implicated in the regulation of the constitutional C-reactive protein (CRP) expression and its response to proinflammatory stimuli. Previous reports suggest that these effects may have an impact on clinical decision-making tools based on CRP, such as the Disease Activity Score in 28 joints (DAS28). We aimed to investigate the possible association between seven CRP SNPs, their haplotypes and the serum levels of CRP, as well as DAS28 scores, in two cohorts of untreated active early rheumatoid arthritis (RA) patients followed during their initial treatment.

METHODS

Overall, 315 patients with RA from two randomized controlled trials (the CIMESTRA and OPERA trials) who were naïve to disease-modifying antirheumatic drugs and steroids with disease durations less than 6 months were included. Seven CRP SNPs were investigated: rs11265257, rs1130864, rs1205, rs1800947, rs2808632, rs3093077 and rs876538. The genotype and haplotype associations with CRP and DAS28 levels were evaluated using linear regression analysis adjusted for age, sex and treatment.

RESULTS

The minor allele of rs1205 C > T was associated with decreased CRP levels at baseline (P = 0.03), with the TT genotype having a 50% reduction in CRP from 16.7 to 8.4 mg/L (P = 0.005) compared to homozygosity of the major allele, but no association was observed at year 1 (P = 0.38). The common H2 haplotype, characterized by the T allele of rs1205, was associated with a 26% reduction in CRP at baseline (P = 0.043), although no effect was observed at year 1 (P = 0.466). No other SNP or haplotype was associated with CRP at baseline or at year 1 (P ≥ 0.09). We observed no associations between SNPs or haplotypes and DAS28 scores at baseline or at year 1 (P ≥ 0.10).

CONCLUSION

CRP genotype and haplotype were only marginally associated with serum CRP levels and had no association with the DAS28 score. This study shows that DAS28, the core parameter for inflammatory activity in RA, can be used for clinical decision-making without adjustment for CRP gene variants.

TRIAL REGISTRATION

The OPERA study is registered at Clinicaltrials.gov (NCT00660647). The CIMESTRA study is not listed in a clinical trials registry, because patients were included between October 1999 and October 2002.

Structural genomic variation as risk factor for idiopathic recurrent miscarriage

Recurrent miscarriage (RM) is a multifactorial disorder with acknowledged genetic heritability that affects ∼3% of couples aiming at childbirth. As copy number variants (CNVs) have been shown to contribute to reproductive disease susceptibility, we aimed to describe genome-wide profile of CNVs and identify common rearrangements modulating risk to RM. Genome-wide screening of Estonian RM patients and fertile controls identified excessive cumulative burden of CNVs (5.4 and 6.1 Mb per genome) in two RM cases possibly increasing their individual disease risk. Functional profiling of all rearranged genes within RM study group revealed significant enrichment of loci related to innate immunity and immunoregulatory pathways essential for immune tolerance at fetomaternal interface. As a major finding, we report a multicopy duplication (61.6 kb) at 5p13.3 conferring increased maternal risk to RM in Estonia and Denmark (meta-analysis, n = 309/205, odds ratio = 4.82, P = 0.012). Comparison to Estonian population-based cohort (total, n = 1000) confirmed the risk for Estonian female cases (P = 7.9 × 10(-4) ). Datasets of four cohorts from the Database of Genomic Variants (total, n = 5,846 subjects) exhibited similar low duplication prevalence worldwide (0.7%-1.2%) compared to RM cases of this study (6.6%-7.5%). The CNV disrupts PDZD2 and GOLPH3 genes predominantly expressed in placenta and it may represent a novel risk factor for pregnancy complications.