Markers of intestinal mucositis to predict blood stream infections at the onset of fever during treatment for childhood acute leukemia

Despite chemotherapy-induced intestinal mucositis being a main risk factor for blood stream infections (BSIs), no studies have investigated mucositis severity to predict BSI at fever onset during acute leukemia treatment. This study prospectively evaluated intestinal mucositis severity in 85 children with acute leukemia, representing 242 febrile episodes (122 with concurrent neutropenia) by measuring plasma levels of citrulline (reflecting enterocyte loss), regenerating islet-derived-protein 3α (REG3α, an intestinal antimicrobial peptide) and CCL20 (a mucosal immune regulatory chemokine) along with the general neutrophil chemo-attractants CXCL1 and CXCL8 at fever onset. BSI was documented in 14% of all febrile episodes and in 20% of the neutropenic febrile episodes. In age-, sex-, diagnosis- and neutrophil count-adjusted analyses, decreasing citrulline levels and increasing REG3α and CCL20 levels were independently associated with increased odds of BSI (OR = 1.6, 1.5 and 1.7 per halving/doubling, all p < 0.05). Additionally, higher CXCL1 and CXCL8 levels increased the odds of BSI (OR = 1.8 and 1.7 per doubling, all p < 0.0001). All three chemokines showed improved diagnostic accuracy compared to C-reactive protein and procalcitonin. These findings underline the importance of disrupted intestinal integrity as a main risk factor for BSI and suggest that objective markers for monitoring mucositis severity may help predicting BSI at fever onset.

Suitability of machine learning models for prediction of clinically defined Stage III/IV periodontitis from questionnaires and demographic data in Danish cohorts

AIM

To evaluate if, and to what extent, machine learning models can capture clinically defined Stage III/IV periodontitis from self-report questionnaires and demographic data.

MATERIALS AND METHODS

Self-reported measures of periodontitis, demographic data and clinically established Stage III/IV periodontitis status were extracted from two Danish population-based cohorts (The Copenhagen Aging and Midlife Biobank [CAMB] and The Danish Health Examination Survey [DANHES]) and used to develop cross-validated machine learning models for the prediction of clinically established Stage III/IV periodontitis. Models were trained using 10-fold cross-validations repeated three times on the CAMB dataset (n = 1476), and the resulting models were validated in the DANHES dataset (n = 3585).

RESULTS

The prevalence of Stage III/IV periodontitis was 23.2% (n = 342) in the CAMB dataset and 9.3% (n = 335) in the DANHES dataset. For the prediction of clinically established Stage III/IV periodontitis in the CAMB cohort, models reached area under the receiver operating characteristics (AUROCs) of 0.67-0.69, sensitivities of 0.58-0.64 and specificities of 0.71-0.80. In the DANHES cohort, models derived from the CAMB cohort achieved AUROCs of 0.64-0.70, sensitivities of 0.44-0.63 and specificities of 0.75-0.84.

CONCLUSIONS

Applying cross-validated machine learning algorithms to demographic data and self-reported measures of periodontitis resulted in models with modest capabilities for the prediction of Stage III/IV periodontitis in two Danish cohorts.

Citrullination of myelin basic protein induces a Th17-cell response in healthy individuals and enhances the presentation of MBP85-99 in patients with multiple sclerosis

The post-translational modification citrullination has been proposed to play a role in the pathogenesis of multiple sclerosis (MS). Myelin basic protein (MBP) is a candidate autoantigen which is citrullinated to a minor extent under physiological conditions and hypercitrullinated in MS. We examined immune cell responses elicited by hypercitrullinated MBP (citMBP) in cultures of mononuclear cells from 18 patients with MS and 42 healthy donors (HDs). The immunodominant peptide of MBP, MBP85-99, containing citrulline in position 99, outcompeted the binding of native MBP85-99 to HLA-DR15, which is strongly linked to MS. Moreover, using the monoclonal antibody MK16 as probe, we observed that B cells and monocytes from HLA-DR15+ patients with MS presented MBP85-99 more efficiently after challenge with citMBP than with native MBP. Both citMBP and native MBP induced proliferation of CD4+ T cells from patients with MS as well as TNF-α production by their B cells and CD4+ T cells, and citrullination of MBP tended to enhance TNF-α secretion by CD4+ T cells from HLA-DR15+ patients. Unlike native MBP, citMBP induced differentiation into Th17 cells in cultures from HDs, while neither form of MBP induced Th17-cell differentiation in cultures from patients with MS. These data suggest a role for citrullination in the breach of tolerance to MBP in healthy individuals and in maintenance of the autoimmune response to MBP in patients with MS.

Interferon alpha-2 treatment reduces circulating neutrophil extracellular trap levels in myeloproliferative neoplasms

Neutrophil extracellular traps (NETs) may play a pathogenic role in the thrombosis associated with myeloproliferative neoplasms (MPNs). We measured serum NET levels in 128 pretreatment samples from patients with MPNs and in 85 samples taken after 12 months of treatment with interferon alpha-2 (PEG-IFNα-2) formulations or hydroxyurea (HU). No differences in NET levels were observed across subdiagnoses or phenotypic driver mutations. In PV, a JAK2V617F⁺ allele burden ≥50% associated with increased NET levels (p = 0.006). Baseline NET levels correlated with neutrophil count (r = 0.29, p = 0.001), neutrophil-to-lymphocyte ratio (r = 0.26, p = 0.004) and JAK2V617F allele burden (r = 0.22, p = 0.03), particularly in patients with PV and with allele burden ≥50% (r = 0.50, p = 0.01, r = 0.56, p = 0.002 and r = 0.45, p = 0.03 respectively). In PV, after 12 months of treatment, NET levels decreased on average by 60% in patients with allele burden ≥50%, compared to only 36% in patients with an allele burden <50%. Overall, treatment with PEG-IFNα-2a or PEG-IFNα-2b reduced NETs levels in 77% and 73% of patients, respectively, versus only 53% of HU-treated patients (average decrease across treatments: 48%). Normalization of blood counts did not per se account for these reductions. In conclusion, baseline NET levels correlated with neutrophil count, NLR and JAK2V617F allele burden, and IFNα was more effective at reducing prothrombotic NET levels than HU.

Blood Cell Biomarkers of Inflammation and Cytokine Levels as Predictors of Response to Biologics in Patients with Psoriasis

For people with psoriasis, biomarkers aiding in the personalization of treatment with biologics are needed. We examined the usefulness of several biomarkers of inflammation in this respect. The neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR), and the systemic immune-inflammation index (SII) were measured in patients with psoriasis initiating TNF-α inhibitors (n = 131), IL-17/IL-17R inhibitors (n = 65), or IL-23/IL-12/23 inhibitors (n = 50). The blood levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, interferon (IFN)-γ, IL-17A, IL-6, soluble IL-6 receptor (sIL-6R), and soluble IL-6 signal transducer (sIL-6ST) were measured in patients initiating adalimumab (n = 62) or IL-17/IL-17R inhibitors (n = 24). Treatment response was defined by a psoriasis area and severity index (PASI) ≤ 2 three months after treatment initiation. Responders to TNF-α inhibitors had a lower NLR at baseline than non-responders (median and interquartile range (IQR) 2.15 (1.67-2.86) vs. 2.54 (1.88-3.55); p = 0.04). Responders to treatment with adalimumab had lower IL-6 levels at baseline than non-responders (0.99 (0.42-1.4) vs. 1.62 (0.96-2.41) pg/mL; p = 0.02). For the majority of patients, the IL-17A, IL-1β, and IFN-γ levels were below quantification limits. NLR and IL-6 may serve as predictive biomarkers of treatment response to TNF-α inhibitor therapy in patients with psoriasis.

A simplified method for monitoring cytokines in wound fluid

Cytokines in wound fluid are used as surrogates for wound healing in clinical research. The current methods used to collect and process wound fluid are noninvasive but not optimal. The aim of this prospective study was to evaluate a method (NovaSwab) by which wound fluid is collected by a surface swab and eluted in a physiological buffer for subsequent cytokine analysis. Wound fluid from 12 patients with leg ulcers was assessed by NovaSwab at the start (Day 0) and at the end of a 23-h collection period of wound fluid retained by foam oblates beneath an occlusive film dressing (Day 1). GM-CSF, IL-1α, IL-1β, IL-6, IL-8, PDGF-AA, TNF-α and VEGF levels were measured by multiplex and electrochemiluminescence assays. IL-1α (2.4×), IL-1β (2.0×) and IL-8 (1.8×) levels increased from Day 0 to Day 1 as detected by NovaSwab, indicating local production of these polypeptides in the wounds. On Day 1, the NovaSwab method yielded higher levels of IL-1α (4.0×), IL-1β (2.7×) and IL-6 (2.7×), and 35% lower levels of VEGF than those in wound fluid accumulated for 23 h in foam oblates (on average, 5 ml of wound fluid). In vitro experiments showed that the investigated cytokines in cell-free wound fluid were recovered in a quantitative manner by the NovaSwab method. We conclude that the method presented here is a promising research tool to study the kinetics of soluble cytokines over the course of wound healing. More studies are needed to determine the interobserver variation and reproducibility of the NovaSwab method.

Influence of Insulin Receptor Single Nucleotide Polymorphisms on Glycaemic Control and Formation of Anti-Insulin Antibodies in Diabetes Mellitus

Single nucleotide polymorphisms (SNPs) in insulin and insulin receptor genes may influence the interaction between the two molecules, as may anti-insulin antibodies (IAs), commonly found in patients with type 1 diabetes mellitus (T1D) or type 2 diabetes mellitus (T2D) treated with exogenous insulin. We examined the impact of two SNPs in the human insulin gene (INS), rs3842752 and rs689, and two in the insulin receptor gene (INSR) rs2245649 and rs2229429, on disease susceptibility, glycaemic control, and IAs formation in 100 T1D patients and 101 T2D patients treated with insulin. 79 individuals without diabetes were typed as healthy controls. The minor alleles of rs3842752 and rs689 in INS protected against T1D (OR: 0.50, p = 0.01 and OR: 0.44; p = 0.002, respectively). The minor alleles of both rs2245649 and rs2229429 in INSR were risk factors for poor glycaemic control (HbA1c ≥ 80 mmol/mol) in T1D (OR: 5.35, p = 0.009 and OR: 3.10, p = 0.01, respectively). Surprisingly, the minor alleles of rs2245649 and rs2229429 in INSR associated strongly with the absence of IAs in T1D (OR = 0.28, p = 0.008 and OR = 0.30, p = 0.002, respectively). In conclusion, the minor alleles of the investigated INS SNPs protect against T1D, and the minor alleles of the investigated INSR SNPs are associated with poor glycaemic control and the absence of IAs in T1D.

Circulating Brodalumab Levels and Therapy Outcomes in Patients With Psoriasis Treated With Brodalumab: A Case Series

Importance

Given the possible treatment modalities in psoriasis management, little is known about whether drug monitoring is associated with response rate.

Objective

To determine whether drug monitoring is associated with response to brodalumab therapy.

Design

A multicenter case series study of patients with psoriasis treated with brodalumab whose treatment with previous IL-17A inhibitor therapy failed. Patients were recruited from the Departments of Dermatology at Gentofte and Aarhus University Hospitals, Denmark, between 2018 and 2020. Patient visits were conducted after 4 and 12 weeks of therapy. Patients not achieving Psoriasis Area and Severity Index 75% improvement from baseline (PASI 75) after 12 weeks were discontinued and considered nonresponders. Patients maintaining PASI 75 response were followed up for up to 52 weeks.

Exposure

Treatment with brodalumab, 210 mg, at weeks 0, 1, 2, then every 2 weeks.

Main Outcomes and Measures

Outcome measures were PASI reductions vs brodalumab levels and antibrodalumab antibodies.

Results

Twenty patients with psoriasis (13 [65%] were male; median age, 50 years [range, 19-66 years]) were included. After 12 weeks of therapy, patients with quantifiable levels of brodalumab (≥0.05 μg/mL) experienced significantly higher PASI reductions than those without (median, 93%; range, 61%-100% vs median, -3; range, -49% to 94%, respectively; P = .006). After 12 weeks of therapy, 4 of 5 patients (80%) not achieving PASI 75 had subquantifiable drug levels (<0.05 μg/mL), although this finding was seen for only 3 of 14 PASI 75 responders (21%). None of 7 patients (35%) with subquantifiable drug levels after 12 weeks of therapy maintained response. No antibrodalumab antibodies were detected in any of the tested samples.

Conclusions and Relevance

Results of this case series study suggest that circulating brodalumab level is a factor associated with clinical treatment response. Monitoring patient levels of circulating brodalumab may aid clinical decision-making and help prevent ineffective therapy.

PADI4 Polymorphisms Confer Risk of Anti-CCP-Positive Rheumatoid Arthritis in Synergy With HLA-DRB1*04 and Smoking

Peptidylarginine deiminases (PADs) catalyze citrullination, a post-translational modification playing a pathogenic role in anti-citrullinated protein antibody (ACPA)-positive rheumatoid arthritis (RA). The interplay between single nucleotide polymorphisms (SNPs) in the PADI genes and known risk factors for ACPA-positive RA, including smoking, HLA-DR4 and -1, and the PTPN22 R620W polymorphism, was investigated. We typed four PADI2 SNPs, four PADI4 SNPs, and the PTPN22 R620W SNP in 445 Danish RA patients and 533 age-matched healthy controls, as well as in 200 North American RA patients and 100 age- and sex-matched controls. The HLA-DRB1 locus was typed in the Danish cohort. Logistic regression analyses, adjusted for age, sex, smoking status, and PTPN22 R620W, revealed increased risk of anti-CCP-positive RA in carriers of rs11203367(T) (OR: 1.22, p=0.03) and reduced risk in carriers of rs2240335(A) in PADI4 (OR: 0.82, p=0.04). rs74058715(T) in PADI4 conferred reduced risk of anti-CCP-negative RA (OR: 0.38, p=0.003). In HLA-DRB1*04-positive individuals, specifically, the risk of anti-CCP-positive RA was increased by carriage of PADI4 rs1748033(T) (OR: 1.54, p=0.007) and decreased by carriage of PADI4 rs74058715(T) (OR: 0.44, p=0.01), and we observed an interaction between these SNPs and HLA-DRB1*04 (p=0.004 and p=0.008, respectively) Thus, PADI4 polymorphisms associate with ACPA-positive RA, particularly in HLA-DRB1*04-positive individuals, and with ACPA-negative RA independently of HLA-DRB1*04.

Effectiveness of brodalumab after previous treatment failure of interleukin-17A inhibitors in patients with psoriasis

Studies on switch between interleukin (IL)-17 inhibitors are scarce. We assessed the effectiveness of brodalumab in patients with previous treatment failure of IL-17A inhibitor(s). Patients with psoriasis and previous treatment failure of an IL-17A inhibitor were treated with brodalumab at standard dose. Effectiveness was assessed after 12, 26, and 52 weeks of treatment. The primary outcome was the proportion of patients that had achieved an absolute psoriasis area and severity index (PASI) ≤2 and/or a relative reduction of PASI of 75% (PASI75) at week 12. Plasma cytokine levels were measured at baseline and after 12 weeks of treatment. In total, 20 patients were included, seven (35%) were female, the median age was 50 years, and the median baseline PASI was 13.5. Analyzing the data using nonresponder imputation, 14 (70%) patients had achieved either PASI75 and/or PASI ≤2, 8 (40%) had achieved PASI90, and three (15%) had achieved PASI100 at week 12. In total, nine patients (45%) completed the 52-weeks trial and seven patients (35%) still had PASI75 throughout 52 weeks. Seventeen out of 20 patients experienced any adverse events (AEs) during 52 weeks with no serious AEs or deaths. Patients responding to treatment had lower levels of tumor necrosis factor (TNF)-α and IL-6 at baseline compared with those who did not respond to treatment (TNF-α, p = 0.041, IL-6, p = 0.0054). In conclusion, treatment with brodalumab despite previous treatment failure with an IL-17A inhibitor can be effective and well-tolerated.

Impact of Probiotics on the Salivary Microbiota and Salivary Levels of Inflammation-Related Proteins during Short-Term Sugar Stress: A Randomized Controlled Trial

Background: The purpose of the present investigation was to characterize the effect of probiotics on the composition of the salivary microbiota and salivary levels of inflammation-related proteins during short-term sugar stress. We tested the hypotheses that consumption of probiotics may partly counteract the detrimental influence of sugar stress on oral homeostasis. Methods: The present study was a five-week, blinded, randomized controlled trial with four study arms—A: sucrose and probiotic (n = 20); B: sucrose and placebo (n = 20); C: xylitol and probiotic (n = 20); D: xylitol and placebo (n = 20). Saliva samples were collected at baseline and after two and five weeks. The salivary microbiota was characterized by means of 16S rDNA sequencing, and sequences were referenced against the Human Oral Microbiome Database (HOMD). Neutrophil gelatinase-associated lipocalin (NGAL) and transferrin levels were quantified using immunoassays. Results: Sugar stress induced a significant increase in the relative abundance of the genus Streptococcus from 29.8% at baseline to 42.9% after two weeks. Changes were transient and were completely reversed three weeks after discontinuation of sugar stress. Xylitol and probiotics alone had no effect on the salivary microbiota, whereas the combination of xylitol and probiotics induced a significant decrease in the relative abundance of Streptococcus species from 37.6% at baseline to 23.0% at week 2. Sugar stress significantly increased salivary transferrin levels, and the effect was partly counteracted by concomitant use of probiotics. Conclusions: The data clearly demonstrate an impact of combined consumption of xylitol and probiotics on the composition of the salivary microbiota. Future studies are needed to evaluate whether the combined use of xylitol and the probiotic strains tested could have clinically protective effects during periods of sugar stress.

Probiotics Do Not Alter the Long-Term Stability of the Supragingival Microbiota in Healthy Subjects: A Randomized Controlled Trial

Background: The purpose of the present study was to longitudinally characterize the supragingival microbiota throughout a three months period in orally healthy individuals. We tested the hypothesis that the supragingival microbiota shows a high degree of compositional stability, which is resilient against the external perturbation of regular use of probiotics, as long as oral health is maintained. Methods: The present study was a double-blinded, randomized, placebo-controlled clinical trial. The study population comprised a total of 110 oral and systemic healthy individuals, distributed in a probiotic (n = 55) and placebo (n = 55) group, where the test group consumed tablets with the probiotic strains Lacticaseibacillusrhamnosus (formerly Lactobacillus) PB01 DSM14870 and Latilactobacillus curvatus (formerly Lactobacillus) EB10 DSM32307 for a period of 12 weeks. Supragingival plaque samples and clinical registrations were performed at baseline, and after 4, 8, and 12 weeks, respectively. The supragingival microbiota was characterized by means of 16S rDNA sequencing. Sequences were referenced against the HOMD database. Results: No significant changes of the core microbiota, as expressed by relative abundance of predominant genera and species were evident during the three months observation period in the probiotic or the placebo group. Conclusions: Data from the present study clearly demonstrate long term compositional stability of the supragingival microbiota as long as oral health is maintained. In addition, the tested probiotics had no augmenting effect on the supragingival microbiota in oral health.

Circulating antibodies against leukotoxin A as marker of periodontitis grades B and C and oral infection with Aggregatibacter actinomycetemcomitans

BACKGROUND

The facultative bacterium Aggregatibacter actinomycetemcomitans (Aa) is strongly associated with periodontitis and is occasionally found in periodontally healthy subjects. We aimed to determine the prevalence of salivary Aa among patients with either periodontitis grade B (periodontitis-B) or grade C (periodontitis-C), periodontally healthy controls (HCs), and to determine if systemic antibodies against Aa or its virulence factor leukotoxin A (LtxA) may serve as biomarkers that reveal the oral presence of the bacterium and discriminate subjects with periodontitis-C, periodontitis-B, or no periodontitis from each other.

METHODS

Serum and unstimulated saliva samples were collected from patients with periodontitis-C (n = 27), patients with periodontitis-B (n = 34), and HCs (n = 28). Serum level of immunoglobulin G antibodies to fragmented whole Aa and to LtxA were quantified using a bead-based assay. Aa was identified in saliva using quantitative polymerase chain reaction (qPCR). All analyses were adjusted for age, sex, and current smoking status.

RESULTS

Aa was present in saliva from 11% of HCs, in 32% of patients with periodontitis-B (P = 0.04 versus HCs), and in 37% of patients with periodontitis-C (P = 0.02 versus HCs). Serum antibodies to fragments of Aa associated significantly with periodontitis-C (P = 0.03), while serum anti-LtxA antibodies associated with both periodontitis-B and periodontitis-C (P = 0.002 and P = 9×10^-4 , respectively). Moreover, a significant association between serum anti-LtxA antibodies and Aa count in saliva was observed (P = 0.001). On the basis of serum anti-LtxA antibody levels, patients with periodontitis could be discriminated from HCs (AUC = 0.74 in ROC curve-analysis, P = 0.0003), and carriers of Aa could be discriminated from non-carriers (AUC = 0.78, P <0.0001).

CONCLUSIONS

Aa is highly prevalent in saliva of patients with periodontitis-B or periodontitis-C. Systemic immunoglobulin G antibodies against LtxA distinguish patients with periodontitis, regardless of grade, from HCs, while their quantity reflects the concurrent bacterial burden in the oral cavity.

Insulin-Like Growth Factor Gene Polymorphisms Predict Clinical Course in Allogeneic Hematopoietic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (HSCT) is challenged by significant toxicities that are propagated by systemic inflammation caused by cytotoxic damage. Insulin-like growth factor-1 (IGF-1) is key in repair of most tissues and is to a large extent genetically determined. We investigated eight single nucleotide polymorphisms (SNPs) in the genes encoding IGF-1 and its binding protein (IGFBP3) in 543 patients undergoing HSCT to access their impact on systemic inflammation and clinical outcomes. Overall, median serum levels of both IGF-1 and IGFBP3 were found reduced from the referral until 2 years post-HSCT compared with healthy sex- and age-matched individuals, but, for individuals homozygous of the known high-producer minor allele of rs1520220 (IGF1), rs978458 (IGF1), or rs2854744 (IGFBP3) serum levels remained normal during the whole period. In accordance, maximum C-reactive protein levels were lower for these genotypes of IGF1 (rs1520220: median 66 vs. 102 mg/L, P = 0.005 and rs978458: 53 vs. 104 mg/L, P < 0.001), translating into borderline significant superior survival (P = 0.060 for rs1520220) and reduced treatment-related mortality (P = 0.050 for rs978458). In conclusion, we found that three SNPs in the IGF-1 axis with known functional impact were associated with circulating IGF-1 or IGFBP-3 levels also in the setting of HSCT, and predictive of the severity of the toxic-inflammatory response during the treatment.

Salivary microbiota and inflammation-related proteins in patients with psoriasis

Objective

The purpose of the present study was to characterize the composition of the salivary microbiota and quantify salivary levels of inflammation‐related proteins (neutrophil gelatinase‐associated lipocalin [NGAL] and transferrin) in patients with psoriasis and compare data to those obtained in patients with periodontitis and orally healthy controls, respectively.

Materials and methods

Stimulated saliva samples from patients with psoriasis (n = 27), patients with periodontitis (n = 58), and orally healthy controls (n = 52) were characterized by means of next‐generation sequencing of the 16S rRNA gene. Salivary levels of NGAL and transferrin were quantified using immunoassays.

Results

Linear discriminant effect size analysis showed that 52 (22 psoriasis‐associated and 30 periodontitis‐associated) and 21 (8 psoriasis‐associated and 13 orally healthy control‐associated) bacterial taxa differentiated the salivary microbiota in patients with psoriasis from that of patients with periodontitis and orally healthy controls, respectively. Significantly lower mean salivary levels of NGAL (psoriasis: 996 [std. error 320], periodontitis: 2,072 [295], orally healthy controls: 2,551 [345] ng/ml, p < .0001) and transferrin (psoriasis: 4.37 [0.92], periodontitis: 7.25 [0.88], orally healthy controls: 10.02 [0.94] ng/ml, p < .0001) were identified in patients with psoriasis.

Conclusions

Psoriasis associates with characteristics of the salivary microbiota and salivary levels of inflammation‐related proteins, which are different from characteristics in patients with periodontitis and orally healthy controls, respectively.

Next-generation sequencing of whole saliva from patients with primary Sjögren's syndrome and non-Sjögren's sicca reveals comparable salivary microbiota

Objective: To characterize and compare the salivary microbiota in patients with pSS and patients with non-Sjögren’s-related sicca, and to relate the findings to their oral health status and saliva flow rates.

Methods: Twenty-four patients fulfilled the 2016 classification criteria for pSS and 34 did not (non-pSS). A clinical examination included registration of decayed, missing and filled teeth/-surfaces and collection of whole saliva. The microbiota was characterized using next-generation sequencing of the V1–V3 region of the 16S rRNA gene. Data were annotated against the eHOMD database.

Results: A total of 509 different bacterial taxa were identified. There were no statistically significant differences between the groups with regard to the abundance of predominant genera, bacterial diversity and relative abundance on the genus or species level. The two groups did not differ with regard to general health, including intake of xerogenic medication and polypharmacy, oral health status or unstimulated and stimulated whole saliva flow rates.

Conclusion: The salivary microbiota and oral health status, as well as salivary flow rate in patients with pSS resemble that of non-pSS patients. Our findings indicate that changes in the salivary microbiota do not appear to be determined by the disease entity pSS itself.

Porphyromonas gingivalis in saliva associates with chronic and aggressive periodontitis

Objective: To characterize the salivary microbiota of patients with aggressive periodontitis, patients with chronica periodontitis and orally healthy individuals.

Methods: A total of 81 unstimulated saliva samples from aggressive periodontitis patients (n = 31), chronic periodontitis patients (n = 25), and orally healthy controls (n = 25) were examined. The V1-V3 region of the 16S rDNA gene was sequenced with Illumina® MiSeq^TM, and sequences were annotated to the expanded Human Oral Microbiome Database (eHOMD).

Results: A mean percentage of 97.6 (range: 89.8–99.7) of sequences could be identified at species level. Seven bacterial species, including Porphyromonas gingivalis, were identified with significantly higher relative abundance in saliva from aggressive periodontitis patients than in saliva from orally healthy controls. Salivary abundance of P. gingivalis could discriminate aggressive (AUC: 0.80, p = 0.0001) and chronic periodontitis (AUC: 0.72, p = 0.006) from healthy controls. Likewise, salivary presence of P. gingivalis was significantly associated with aggressive (p < 0.0001, RR: 8.1 (95% CI 2.1–31.2)) and chronic periodontitis (p = 0.002, RR: 6.5 (95% CI: 1.6–25.9)).

Conclusion: Salivary presence and relative abundance of P. gingivalis associate with aggressive and chronic periodontitis, but do not discriminate between aggressive and chronic periodontitis.

Associations between serum and plasma brain-derived neurotrophic factor and influence of storage time and centrifugation strategy

The aims of the study were to clarify the impact of storage time and centrifugation strategy on brain-derived neurotrophic factor (BDNF) levels in human serum and plasma samples. In addition, we analyzed associations between BDNF levels, cardiorespiratory fitness and waist circumference. Seventeen healthy males (25.2 (4.1) years) were included in the study. Blood samples were drawn after an overnight fast and treated to different protocols, varying in time before centrifugation and centrifugation strategy. BDNF was analyzed in serum, normal plasma (NP) and platelet-poor plasma (PPP). Also, waist circumference and cardiorespiratory fitness were measured. A large increase was observed in serum BDNF levels during the first hour of clotting. BDNF in NP correlated with PPP, whereas no correlations were found between BDNF in serum and plasma. Though not statistical significant, correlations between fitness and BDNF in serum changed from positive at 30 min. to negative when clotting time was ≥60 min. In conclusion, BDNF levels in serum were affected by clotting time, whereas BDNF levels in plasma were influenced by centrifugation strategy. Importantly, BDNF in serum and plasma appears to reflect two different pools of BDNF. The biological relevance of the velocity of BDNF release during clotting and its dependence upon fitness must be investigated further.

Adjunctive dabigatran therapy improves outcome of experimental left-sided Staphylococcus aureus endocarditis

Background

Staphylococcus aureus is the most frequent and fatal cause of left-sided infective endocarditis (IE). New treatment strategies are needed to improve the outcome. S. aureus coagulase promotes clot and fibrin formation. We hypothesized that dabigatran, could reduce valve vegetations and inflammation in S. aureus IE.

Methods

We used a rat model of severe aortic valve S. aureus IE. All infected animals were randomized to receive adjunctive dabigatran (10 mg/kg b.i.d., n = 12) or saline (controls, n = 11) in combination with gentamicin. Valve vegetation size, bacterial load, cytokine, cell integrins expression and peripheral platelets and neutrophils were assessed 3 days post-infection.

Results

Adjunctive dabigatran treatment significantly reduced valve vegetation size compared to controls (p< 0.0001). A significant reduction of the bacterial load in aortic valves was seen in dabigatran group compared to controls (p = 0.02), as well as expression of key pro-inflammatory markers keratinocyte-derived chemokine, IL-6, ICAM-1, TIMP-1, L-selectin (p< 0.04). Moreover, the dabigatran group had a 2.5-fold increase of circulating platelets compared to controls and a higher expression of functional and activated platelets (CD62p⁺) unbound to neutrophils.

Conclusion

Adjunctive dabigatran reduced the vegetation size, bacterial load, and inflammation in experimental S. aureus IE.

Lewis and AB0 blood group-phenotypes in periodontitis, cardiovascular disease, obesity and stroke

The AB0 blood group has been linked to ischaemic heart disease, stroke, and periodontal disease, while the Lewis blood group has been linked to ischaemic heart disease and obesity, all of which have been associated with periodontitis. AB0 or Lewis blood group phenotype may therefore constitute common hereditary components predisposing to these disorders. In this study, we investigated if blood group phenotype associated with periodontitis in a subpopulation consisting of 702 participants from a Danish cross-sectional cohort and, secondarily, attempted to confirm their association with hypertension, ischaemic heart disease, stroke, and obesity. No significant association between blood group phenotype and periodontitis was detected, nor were previously reported associations between blood group phenotype and hypertension, ischaemic heart disease, stroke, and obesity confirmed. This may, at least partly, be attributed to differences in study type, outcome definitions, cohort sizes, and population attributable factors. However, our results suggested a strong association between self-reported stroke and the Lewis (a−b−) phenotype (P = 0.0002, OR: 22.28; CI 95: 4.72–131.63).

Inflammatory functional iron deficiency common in myelofibrosis, contributes to anaemia and impairs quality of life. From the Nordic MPN study Group

OBJECTIVES

The study investigates the hypothesis that inflammation in myelofibrosis (MF) like in myeloma and lymphoma, may disturb iron distribution and contribute to anaemia.

METHODS

A cross-sectional study of 80 MF and 23 ET patients was performed.

RESULTS

About 35% of anaemic MF patients had functional iron deficiency (FID) with transferrin saturation <20 and normal or elevated S-ferritin (<500 µg/L). In ET, FID was rare. In MF patients with FID, 70.6% were anaemic, vs 29.4% in patients without FID (P = 0.03). Hepcidin was significantly higher in MF patients with anaemia, including transfusion-dependent patients, 50.6 vs 24.4 µg/L (P = 0.01). There was a significant negative correlation between Hb and inflammatory markers in all MF patients: IL-2, IL-6 and TNF-α, (P < 0.01-0.03), LD (P = 0.004) and hepcidin (P = 0.03). These correlations were also seen in the subgroup of anaemic MF patients (Table ). Tsat correlated negatively with CRP (P < 0.001). Symptom burden was heavier in MF patients with FID, and MPN-SAF quality of life scores correlated with IL-6 and CRP.

CONCLUSIONS

The inflammatory state of MF disturbs iron turnover, FID is common and contributes to anaemia development and impairment of QoL. Anaemic MF patients should be screened for FID.

Peptidylarginine deiminase-4 gene polymorphisms are associated with systemic lupus erythematosus and lupus nephritis

OBJECTIVE

Peptidylarginine deiminase-4 (PAD4) is highly expressed by neutrophils and essential for citrullination occurring during the formation of neutrophil extracellular traps, which have been implicated in the pathogenesis of systemic lupus erythematosus (SLE) and lupus nephritis (LN). Single-nucleotide polymorphisms (SNPs) in PADI4 influence PAD4 expression and functionality. Here, we investigate whether SNPs in PADI4 influence the risk of SLE or LN.

METHOD

Altogether, 234 SLE patients and 484 controls were genotyped for nine PADI4 SNPs known to alter PAD4 functionality and/or expression, or to be associated with other autoimmune diseases, using an in-house multiplex Luminex assay. All analyses were adjusted for age and gender.

RESULTS

Heterozygosity for rs1748033, and heterozygosity and homozygosity for rs1635564, were associated with increased occurrence of SLE [odds ratio (OR) 1.55, 95% confidence interval (CI) 1.08-2.23; OR 1.52, 95% CI 1.06-2.19; and OR 2.06, 95% CI 1.08-3.93, respectively]. Homozygosity for rs1635564 was also associated with increased occurrence of LN (OR 3.35, 95% CI 1.2-10.97). Notably, gene dose effects of the rs1635564 variant allele were observed for SLE (p = 0.005) and LN (p = 0.01). Carriage of minor alleles of five other SNPs (rs11203366, rs11203367, rs874881, rs2240340, and rs11203368) was associated with increased occurrence of LN and hypertension.

CONCLUSION

The rs1635564 polymorphism of PADI4 is a candidate risk factor for SLE, particularly with renal involvement. Additional PADI4 polymorphisms also conferred increased risk of LN. Overall, these findings support the notion of PAD4 contributing to the pathogenesis of SLE and LN.

Donor Genotype in the Interleukin-7 Receptor α-Chain Predicts Risk of Graft-versus-Host Disease and Cytomegalovirus Infection after Allogeneic Hematopoietic Stem Cell Transplantation

The efficacy of allogeneic hematopoietic stem cell transplantation (HSCT) is challenged by acute and chronic graft-versus-host disease (aGVHD and cGVHD) and viral infections due to long-lasting immunodeficiency. Interleukin-7 (IL-7) is a cytokine essential for de novo T cell generation in thymus and peripheral T cell homeostasis. In this study, we investigated the impact of the single nucleotide polymorphism rs6897932 in the IL-7 receptor α-chain (IL-7Rα) which has previously been associated with several autoimmune diseases. We included 460 patients undergoing allogeneic HSCT after a myeloablative conditioning. Patients had a median age of 26.3 years (0.3-67.0 years), and 372 (80.9%) underwent HSCT for malignant diseases. Donors were matched sibling donors (n = 147), matched unrelated donors (n = 244) or mismatched unrelated donors (n = 69), and the stem cell source were either bone marrow (n = 329) or peripheral blood (n = 131). DNA from donors was genotyped for the IL-7Rα single nucleotide polymorphism (SNP) rs6897932 using an allele-specific primer extension assay (CC: n = 252, CT: n = 178, TT: n = 30). The donor T allele was associated with a higher risk of grades III-IV aGVHD (HR = 2.0, 95% CI = 1.1-3.8, P = 0.034) and with significantly increased risk of extensive cGVHD (HR = 2.0, 95% CI = 1.1-3.6, P = 0.025) after adjustment for potential risk factors. In addition, the TT genotype was associated with a higher risk of cytomegalovirus (CMV) infection post-transplant (HR = 2.4, 95% CI = 1.2-4.3, P = 0.0068). Numbers of T cells were significantly higher on day +60 in patients receiving a rs6897932 TT graft (CD3+: 109% increase, P = 0.0096; CD4+: 64% increase, P = 0.038; CD8+: 133% increase, P = 0.011). Donor heterozygosity for the T allele was associated with inferior overall survival (HR = 1.7, 95% CI = 1.2-2.3, P = 0.0027) and increased treatment-related mortality (HR = 2.3, 95% CI = 1.3-4.0, P = 0.0047), but was not associated with the risk of relapse (P = 0.35). In conclusion, the IL-7Rα rs6897932 genotype of the donor is predictive of aGVHD and cGVHD, CMV infection, and mortality following HSCT. These findings indicate that IL-7Rα SNP typing of donors may optimize donor selection and facilitate individualization of treatment in order to limit treatment-related complications.

Development of anti-drug antibodies is associated with shortened survival in patients with metastatic melanoma treated with ipilimumab

Introduction: Checkpoint inhibitors, including the CTLA-4 blocking antibody ipilimumab, have become the new standard therapy for many metastatic cancers. Development of anti-drug antibodies (ADAs) after treatment with other biopharmaceuticals has been thoroughly described, but the induction of ADAs after treatment with checkpoint inhibitors has been inadequately investigated. In this retrospective study, we relate ipilimumab serum levels and anti-ipilimumab antibody levels to clinical outcomes in patients with metastatic melanoma (MM). Method: Serum samples from 31 patients with MM were analyzed for serum levels of ipilimumab and ADAs to ipilimumab at baseline, and before the 2nd and 4th infusion using an in-house bead-based assay. The results were correlated with progression-free survival (PFS) and overall survival (OS). Results: Low serum levels of ipilimumab before the 2nd infusion correlated significantly with a shorter OS (p = 0.01) and PFS (p = 0.02). Eight patients (26%) were ADA-positive at either timepoint. ADA positivity correlated significantly with a shorter OS (p = 0.03) with a hazard ratio (HR) of 3.0 (95% CI: 1.2-7.8). Four of 8 ADA-positive patients (50%) discontinued therapy before the 4th infusion due to disease progression, compared to three of 23 (13%) ADA-negative patients. Conclusion: We confirm that low serum levels of ipilimumab are associated with a shortened OS, and we show for the first time that ADAs to ipilimumab are associated with shorter OS in patients with MM.

Immunoglobulin G antibodies against Porphyromonas gingivalis or Aggregatibacter actinomycetemcomitans in cardiovascular disease and periodontitis

Objectives: The aim was to elucidate whether levels of circulating antibodies to Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis correlate to loss of attachment, as a marker for periodontitis and cardiovascular disease (CVD). Design: Sera were collected from 576 participants of the Danish Health Examination Survey (DANHES). Immunoglobulin G antibodies against lipopolysaccharide (LPS) and protein antigens from the a, b and c serotypes of A. actinomycetemcomitans and P. gingivalis were quantified by titration in ELISA plates coated with a mixture of antigens prepared by disintegration of bacteria. Results: Levels of antibodies against P. gingivalis (OR = 1.48) and A. actinomycetemcomitans (1.31) associated with periodontitis, as determined by univariable logistic regression analysis. These antibody levels also associated with CVD (1.17 and 1.37), respectively, However, after adjusting for other risk factors, including age, smoking, gender, alcohol consumption, overweight, and level of education using multivariable logistic regression analysis, only increasing body mass index (BMI; 1.09), previous smoking (1.99), and increasing age (decades) (2.27) remained associated with CVD. Increased levels of antibodies against P. gingivalis (1.34) remained associated with periodontitis after adjusting for other risk factors. Conclusions: CVD and periodontitis were associated with levels of IgG antibodies to P. gingivalis or A. actinomycetemcomitans in univariable analyses, but only the association of P. gingivalis antibody levels with periodontitis reached statistical significance after adjustment for common confounders. Age, in particular, influenced this relationship.

Impact of Periodontitis Case Criteria: A Cross-Sectional Study of Lifestyle

BACKGROUND

Associations of risk factors/indicators with periodontitis may depend on the included case criterion. The objective of the current study is to evaluate differences in outcome by applying five periodontitis case definitions for cross-sectional associations with lifestyle factors among participants of the Danish Health Examination Survey (DANHES).

METHODS

A total of 4,402 adults aged 18 to 96 years from the general health examination of DANHES had a periodontal examination consisting of half-mouth registration at six sites per tooth including probing depth (PD) and clinical attachment level (CAL). Periodontitis was defined according to severe periodontitis, European Workshop of Periodontology (EWP)-specific, meanCAL ≥2.55 mm, CAL-tertile, and PD-CAL definitions. Multivariable logistic regression models fitted the association of age, sex, smoking status, diabetes mellitus, educational level, alcohol consumption, body mass index, physical activity, body fat percentage, waist circumference, triglycerides, total cholesterol, and C-reactive protein with periodontitis.

RESULTS

Number of cases captured by the five periodontitis case definitions ranged from 337 (9.2%) to 1,136 (31.0%). A total of 224 participants were defined as periodontitis cases by all five criteria. Analyses on 3,665 participants with complete data revealed statistically significant associations of age and smoking with all periodontitis case definitions and of male sex with severe periodontitis and EWP-specific definitions. Educational level (two lowest groups) was related to three periodontitis criteria. Among obesity and hyperlipidemia measures no factors were related to periodontitis.

CONCLUSION

Regression analyses showed little difference in odds ratio across the five periodontitis case definitions; however, the level of significance did show some variation.

In vitro complement activation, adherence to red blood cells and induction of mononuclear cell cytokine production by four strains of Aggregatibacter actinomycetemcomitans with different fimbriation and expression of leukotoxin

BACKGROUND AND OBJECTIVE

The periodontal pathogen Aggregatibacter actinomycetemcomitans has been proposed as pro-atherogenic, and complement-mediated adherence to red blood cells (RBCs) may facilitate its systemic spread. We investigated the ability of four strains of A. actinomycetemcomitans with differential expression of leukotoxin A (LtxA) and fimbriae to activate complement, adhere to RBCs and elicit cytokine responses by mononuclear cells (MNCs).

MATERIAL AND METHODS

Aggregatibacter actinomycetemcomitans serotype b strains HK 921, HK 1651, HK 2092 and HK 2108 were fluorescence-labeled, incubated with human whole blood cells in the presence of autologous serum, and assessed for RBC adherence by flow cytometry and for capacity to induce cytokine production by cytometric bead array analysis. The levels of IgG to A. actinomycetemcomitans serotype b were quantified by ELISA, as was consumption of complement.

RESULTS

The JP2 clone variants HK 1651 and, to a lesser extent, HK 2092, consumed complement efficiently, while HK 2108 (= strain Y4) consumed complement poorly. Nonetheless, the four tested strains adhered equally well to RBCs in the presence of autologous serum, without causing RBC lysis. The JP2 clone variant HK 2092, selectively lacking LtxA production, induced higher production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and IL-10 by MNCs than did the other three strains, while the four strains induced similar production of IL-12p70. RBCs facilitated the HK 2092-induced production of TNF-α and IL-1β, and IL-6 was enhanced by RBCs, and this facilitation could be counteracted by blockade of complement receptor 3 (CD11b/CD18).

CONCLUSION

Our data suggest that the JP2 clone of A. actinomycetemcomitans, most closely resembled by the variant HK 1651, activates complement well, while strain Y4, represented by HK 2108, activates complement poorly. However, all strains of A. actinomycetemcomitans adhere to RBCs and, when capable of producing LtxA, prevent production of inflammatory cytokines by MNCs. This "immunologically silent" immune adherence may facilitate systemic spread and atherogenesis.

Viable bacteria associated with red blood cells and plasma in freshly drawn blood donations

Objectives

Infection remains a leading cause of post-transfusion mortality and morbidity. Bacterial contamination is, however, detected in less than 0.1% of blood units tested. The aim of the study was to identify viable bacteria in standard blood-pack units, with particular focus on bacteria from the oral cavity, and to determine the distribution of bacteria revealed in plasma and in the red blood cell (RBC)-fraction.

Design

Cross-sectional study. Blood were separated into plasma and RBC-suspensions, which were incubated anaerobically or aerobically for 7 days on trypticase soy blood agar (TSA) or blue lactose plates. For identification colony PCR was performed using primers targeting 16S rDNA.

Setting

Blood donors attending Capital Region Blood Bank, Copenhagen University Hospital, Rigshospitalet, Hvidovre, Denmark, October 29^th to December 10^th 2013.

Participants

60 donors (≥50 years old), self-reported medically healthy.

Results

Bacterial growth was observed on plates inoculated with plasma or RBCs from 62% of the blood donations. Growth was evident in 21 (35%) of 60 RBC-fractions and in 32 (53%) of 60 plasma-fractions versus 8 of 60 negative controls (p = 0.005 and p = 2.6x10^-6, respectively). Propionibacterium acnes was found in 23% of the donations, and Staphylococcus epidermidis in 38%. The majority of bacteria identified in the present study were either facultative anaerobic (59.5%) or anaerobic (27.8%) species, which are not likely to be detected during current routine screening.

Conclusions

Viable bacteria are present in blood from donors self-reported as medically healthy, indicating that conventional test systems employed by blood banks insufficiently detect bacteria in plasma. Further investigation is needed to determine whether routine testing for anaerobic bacteria and testing of RBC-fractions for adherent bacteria should be recommended.

Toll-like receptor polymorphisms in allogeneic hematopoietic cell transplantation

To assess the impact of the genetic variation in toll-like receptors (TLRs) on outcome after allogeneic myeloablative conditioning hematopoietic cell transplantation (HCT), we investigated 29 single nucleotide polymorphisms across 10 TLRs in 816 patients and donors. Only donor genotype of TLR8 rs3764879, which is located on the X chromosome, was significantly associated with outcome at the Bonferroni-corrected level P ≤ .001. Male hemizygosity and female homozygosity for the minor allele were significantly associated with disease-free survival (hazard ratio [HR], 1.47 [95% confidence interval {CI}, 1.16 to 1.85]; P = .001). Further analysis stratified by donor sex due to confounding by sex was suggestive for associations with overall survival (male donor: HR, 1.41 [95% CI, 1.09 to 1.83], P = .010; female donor: HR, 2.78 [95% CI, 1.43 to 5.41], P = .003), disease-free survival (male donor: HR, 1.45 [95% CI, 1.12 to 1.87], P = .005; female donor: HR, 2.34 [95% CI, 1.18 to 4.65], P = .015), and treatment-related mortality (male donor: HR, 1.49 [95% CI, 1.09 to 2.04], P = .012; female donor: HR, 3.12 [95% CI, 1.44 to 6.74], P = .004). In conclusion, our findings suggest that the minor allele of TLR8 rs3764879 of the donor is associated with outcome after myeloablative conditioned allogeneic HCT.

Genetic polymorphisms of dsRNA ligating pattern recognition receptors TLR3, MDA5, and RIG-I. Association with systemic lupus erythematosus and clinical phenotypes

This study aimed to demonstrate possible associations between genetic polymorphisms in Toll-like receptor 3, interferon induced with helicase C domain 1 (IFIH1) and DEAD (Asp-Glu-Ala-Asp) box polypeptide 58 and systemic lupus erythematosus (SLE), including the phenotypes lupus nephritis and malar rash, as well as the presence of autoantibodies against nucleic acid-containing complexes. Genotyping was carried out in two Danish cohorts [Copenhagen (CPH) and Odense (ODE)] totaling 344 patients and was compared with 641 previously genotyped healthy controls. In the ODE cohort, the patients were only genotyped for the rs1990760 polymorphism of IFIH1. Single nucleotide polymorphisms (SNPs) were determined by a multiplex bead-based assay (CPH cohort) or real-time PCR (ODE cohort). Associations were investigated using the Cochran-Armitage trend test. The odds ratio (OR) for minor allele homozygotes versus major allele homozygotes suggested a protective effect of the IFIH1 rs1990760 SNP for SLE in the ODE cohort [OR 0.52, 95 % confidence intervals (95 % CI) 0.31-0.88, Pcorr. = 0.05] but not in the CPH cohort, although the OR suggested a trend in the same direction, and when combining the two patient cohorts, ORs were 0.57, 95 % CI 0.37-0.88. None of the other investigated polymorphisms showed any association with SLE. Regarding phenotypes, we found a statistically significant association between rs1990760 and malar rash in the CPH cohort, with ORs suggesting a protective effect (OR 0.28, 95 % CI 0.13-0.62 for heterozygotes and OR 0.11, 95 % CI 0.03-0.41 for homozygotes, Pcorr. = 0.0001). There were no significant associations between rs1990760 and presence of anti-dsDNA, anti-U1RNP, or anti-Smith antibodies. Our study supports previous findings of an association between the rs1990760 polymorphism of IFIH1 and SLE and indicates that this SNP may also be associated with malar rash in SLE patients although this finding needs confirmation.

Single nucleotide polymorphisms in genes encoding toll-like receptors 7, 8 and 9 in Danish patients with systemic lupus erythematosus

Several studies indicate a role for toll-like receptors (TLRs) in the pathogenesis of systemic lupus erythematosus (SLE). We aimed to investigate the risk of SLE and typical clinical and serological manifestations of SLE potentially conferred by selected single nucleotide polymorphisms (SNPs) of genes encoding TLR7, TLR8, and TLR9. Using a multiplexed bead-based assay, we analyzed eight SNPs in a cohort of 142 Danish SLE patients and a gender-matched control cohort comprising 443 individuals. Our results showed an association between the rs3853839 polymorphism of TLR7 and SLE (G vs. C, P = 0.008, OR 1.60, 95 % CI 1.12-2.27 in females; P = 0.02, OR 4.50, 95 % CI 1.18-16.7 in males) confirming recent findings in other populations. Additionally, an association between the rs3764879 polymorphism of TLR8 and SLE (G vs. C, P < 0.05, OR 1.36, 95 % CI 0.99-1.86 in females; P = 0.06, OR 4.00, 95 % CI 0.90-17.3 in males) was found. None of the other investigated SNPs were associated with SLE but several SNPs were associated with clinical and serological manifestations. In summary, a previously shown association between the rs3853839 SNP of TLR7 and SLE in Asian patients was also found in Danish patients. Together with the association of several other SNPs of TLR8 and TLR9 with various clinical and serological manifestations of SLE these findings corroborate the pathogenic significance of TLRs in SLE.

Genetic polymorphisms of tumour necrosis factor receptor superfamily 1b and fas ligand are associated with clinical efficacy and/or acute severe infusion reactions to infliximab in Crohn's disease

BACKGROUND

Single nucleotide polymorphisms (SNPs) in TNF receptor superfamily (TNFRSF) 1A and 1B, and Fas ligand (FASLG) genes, have been associated with responsiveness to infliximab (IFX) in Crohn's disease.

AIM

To investigate if SNPs in TNFRSF1A and 1B, and FAS (TNFRSF6) and FASLG (TNFSF6), associated with short- or long-term clinical and biological efficacy and with acute severe infusion reactions.

METHODS

Observational, retrospective and explorative cohort study of IFX-treated Caucasian patients with Crohn's disease classified as primary nonresponders (n = 21), response failures on maintenance therapy (n = 37), maintained remission (n = 47) and occurrence of acute severe infusion reactions (n = 20).

RESULTS

During IFX maintenance therapy, minor allele carriage of TNFRSF1B, rs976881 is associated with loss of response [OR 3.3 (1.2-9.1), P = 0.014]. Minor allele homozygosity increased the risk substantially (OR estimated 19, P = 0.006), and furthermore associated with a mean CRP increase of 17 mg/L as compared to a mean decrease of 17 mg/L in all others (P = 0.036). In contrast, minor allele carriage of TNFRSF1B, rs1061622 is associated with beneficial response to IFX induction [OR 4.2 (1.2-18.2), P = 0.014], and with persistence of remission during maintenance therapy [OR 5.5 (1.5-25.5), P = 0.007]. Carriage of the minor allele of FASLG, rs76110 increased risk of severe infusion reactions [OR 4.0 (1.1-22.4), P = 0.041]; minor allele carriage of TNFRSF1B, rs652625 decreased the risk (OR estimated 0.2, P = 0.043 ).

CONCLUSIONS

The TNFRSF1B polymorphisms may contribute to predict efficacy of infliximab. Moreover, FASLG and TNFRSF1B polymorphisms may confer genetic susceptibility to severe infusion reactions. These findings could potentially aid clinical decisions if confirmed in larger studies.

Variation in NOD2 augments Th2- and Th17 responses to myelin basic protein in multiple sclerosis

Variations in the gene for the nucleotide-binding oligomerisation domain (NOD) 2 have been associated with Crohn's disease but not multiple sclerosis (MS). Here we investigate the effect of three polymorphisms in the NOD2 gene (rs5743277, rs2066842 and rs5743291) on cytokine production and CD4+ T cell proliferation elicited by human myelin basic protein (MBP) in blood mononuclear cell (MNC) cultures from 29 patients with MS. No polymorphism was observed at rs5743277. No associations with the rs2066842 polymorphism were found. Concerning rs5743291, none were homozygous for the minor allele. Seven of 29 (24%) patients were heterozygous, and five of these (71%) exhibited increased MBP-induced CD4+ T cell proliferation versus four of 22 (18%), who were homozygous for the major allele (p<0.04). Interleukin (IL)-5 was induced by MBP in MNC from the same five carriers versus two (9%) homozygotes (p<0.004); four carriers (57%) versus three non-carriers (14%) exhibited IL-17 responses to MBP (p<0.04). By contrast, we found no association between the polymorphisms investigated and interferon-gamma-, tumor necrosis factor-alpha-, IL-2, -4- or IL-10 responses to MBP. These results indicate that the rs5743291 polymorphism influences T helper (Th) cell 2- and Th17 cell responses in MNC from MS patients.

Genetic variants in toll-like receptors are not associated with rheumatoid arthritis susceptibility or anti-tumour necrosis factor treatment outcome

Background

Several studies point to a role of Toll-like receptors (TLRs) in the development of rheumatoid arthritis (RA). We investigated if genetic variants in TLR genes are associated with RA and response to tumour necrosis factor blocking (anti-TNF) medication.

Methodology and Principal Findings

22 single nucleotide polymorphisms (SNPs) in seven TLR genes were genotyped in a Dutch cohort consisting of 378 RA patients and 294 controls. Significantly associated variants were investigated in replication cohorts from The Netherlands, United Kingdom and Sweden (2877 RA patients and 2025 controls). 182 of the Dutch patients were treated with anti-TNF medication. Using these patients and a replication cohort (269 Swedish patients) we analysed if genetic variants in TLR genes were associated with anti-TNF outcome. In the discovery phase of the study we found a significant association of SNPs rs2072493 in TLR5 and rs3853839 in TLR7 with RA disease susceptibility. Meta-analysis of discovery and replication cohorts did not confirm these findings. SNP rs2072493 in TLR5 was associated with anti-TNF outcome in the Dutch but not in the Swedish population.

Conclusion

We conclude that genetic variants in TLRs do not play a major role in susceptibility for developing RA nor in anti-TNF treatment outcome in a Caucasian population.

Enhancement of natural killer cell activity in healthy subjects by Immulina®, a Spirulina extract enriched for Braun-type lipoproteins

Immulina®, a commercial extract of Arthrospira (Spirulina) platensis is a potent activator of THP-1 monocytes and CD4+ T cells IN VITRO and enhances several immunological functions in mice. We further characterized Immulina® by determining that Braun-type lipoproteins are responsible for a major portion of the IN VITRO monocyte activation exhibited by this material. In order to understand the effect of Immulina® on NK cell activity, a pilot study was conducted on ten healthy North American individuals who supplemented their diet with Immulina® (400 mg/day) for seven days. We observed a 40% average increase in the killing of K562 tumor cells by NK cells (p < 0.01) after Immulina® supplementation. In a separate placebo-controlled, crossover study involving 11 healthy Danish subjects, we observed increased mRNA expression of the NK cell marker NKG2D by 37% (p = 0.02) and by 55% (p = 0.0003) after administration of Immulina® (200 mg and 400 mg per day, respectively) for seven days. The mRNA expression of the NK- and T-cell marker perforin increased by 75% (p = 0.008) after administration of 400 mg Immulina® per day. Both markers displayed significant dose-dependent effects (p = 0.0003 and p = 0.02, respectively). The ratio between CD56 (bright) and CD56 (dim) NK cells was not affected by Immulina® administration. In summary, two independent studies showed enhancement of NK cell activity following administration of Immulina® for seven days.

Polymorphisms of innate pattern recognition receptors, response to interferon-beta and development of neutralizing antibodies in multiple sclerosis patients

BACKGROUND

Interferon-beta therapy of patients with relapsing-remitting multiple sclerosis involves repeated 'immunizations' with exogenous protein solutions. Innate pattern recognition receptors play an important role in immune responses towards foreign substances and may thus be related to treatment outcome.

OBJECTIVE

To determine the genotypes at 42 single nucleotide polymorphism loci in selected pattern recognition receptors for 567 prospectively followed relapsing-remitting multiple sclerosis patients treated with recombinant interferon-beta, and test for relationships to several outcome parameters, including formation of interferon-beta neutralizing antibodies.

RESULTS

The results suggest an association between the rs5743810 polymorphism (Ser249Pro) of TLR6 and development of neutralizing antibodies after 24 months of therapy in males (p = 0.00002), but not in females (p = 0.2). This association survived crude Bonferroni correction (p (corrected) = 0.02). Additional associations were observed in carriers of the TLR2-rs5743708 and NOD2-rs3135499 SNPs (time to relapse), the TLR7-rs179008 and NOD1-rs2075820 SNPs (time to disease progression) and the TLR4-rs7873784, TLR9-rs5743836, and NOD2-rs2066842 SNPs (frequency of neutralizing antibodies development). All of these, however, failed to survive correction for multiple testing. There were no significant differences between interferon-beta responders and non-responders for any of the investigated single nucleotide polymorphisms.

CONCLUSIONS

The rs5743810 polymorphism of TLR6 may be involved in development of anti-interferon-beta antibodies in males, although further studies are required to firmly establish this.

Multiple sclerosis and polymorphisms of innate pattern recognition receptors TLR1-10, NOD1-2, DDX58, and IFIH1

Genetic factors are critical in multiple sclerosis (MS), and it is conceivable that the pattern recognition receptors of the innate immune system are of pathogenic importance. We therefore developed two novel assays capable of analyzing 42 single-nucleotide polymorphisms in the human genes encoding TLR1-10, NOD1-2, DDX58, and IFIH1. Using these assays, we genotyped 963 MS patients and 960 controls, and analyzed for possible associations to MS diagnosis, clinical course, severity, and age at onset. Our results support previous findings of associations between the IFIH1-locus and MS (IFIH1-rs3747517 and IFIH1-rs1990760 trend test: P=0.002 and P=0.014, respectively).

Formation of antibodies against infliximab and adalimumab strongly correlates with functional drug levels and clinical responses in rheumatoid arthritis

BACKGROUND

Tumour necrosis factor alpha (TNFalpha) neutralising antibody constructs are increasingly being used to treat rheumatoid arthritis (RA).

OBJECTIVE

To determine potential differences in clinical responses, soluble drug levels and antibody formation between patients with RA receiving infliximab and adalimumab.

METHODS

69 patients with RA fulfilling the 1987 American College of Rheumatology criteria and about to start treatment with infliximab or adalimumab, were enrolled consecutively. All patients had active disease (28-joint count Disease Activity Score >3.2). Infliximab was given intravenously at 3 mg/kg at baseline and after 2, 6 and 14 weeks. Adalimumab was administered as 40 mg biweekly subcutaneously. Concomitant drug treatment was monitored and continued at constant dosage during the study. All serum samples were tested for infliximab/adalimumab levels and anti-infliximab/anti-adalimumab antibodies.

RESULTS

35 patients received infliximab, 34 received adalimumab. At 6 months, 15 (43%), 6 (17%) and 14 (40%) of the infliximab-treated patients fulfilled the EULAR criteria for good, moderate and non-responders, respectively, whereas the corresponding figures for adalimumab-treated patients were 16 (47%), 8 (24%) and 10 (29%). Clinical responses correlated with the levels of S-infliximab/adalimumab and the formation of anti-infliximab/anti-adalimumab antibodies.

CONCLUSION

The clinical response to two anti-TNFalpha biological agents closely follows the trough drug levels and the presence of antibodies directed against the drugs. Further studies that focus on the underlying pathways leading to antibody formation are warranted to predict immunogenicity of these expensive biological agents and treatment outcomes.