To Örebro University

BACKGROUND: Rituximab, a B-cell-depleting therapy widely used for multiple sclerosis (MS), is associated with a progressive decline in immunoglobulin G (IgG) levels, raising concerns regarding infection risk. This study evaluates IgG dynamics and antibiotic use in a real-world MS cohort.

METHODS: A retrospective cohort study was conducted on MS patients treated with Rituximab over a 10-year period. Patients included had at least two infusions and a follow-up of ≥6 months after the last infusion. IgG levels and antibiotic prescriptions were registered longitudinally.

RESULTS: The study included 213 patients (72% female, mean age 40.1 ± 10.6 years). Mean IgG decreased from 11.5 ± 2.4 g/L at baseline to 9.0 ± 1.7 g/L after five years, with an average decline of 0.35 g/L/year (95% CI 0.25-0.44; p < 0.001). Hypogammaglobulinemia (<6.7 g/L) occurred in 7.5% of patients. Cumulative rituximab dose was a significant predictor of lower IgG (p < 0.001). Antibiotic prescriptions were recorded in 62% of patients (mean 2.5 per patient), most commonly for urinary (29%) and respiratory (17%) tract infections. In multivariable analysis, lower IgG levels did not significantly predict the risk of antibiotic prescription.

CONCLUSION: Rituximab treatment resulted in a significant, dose-dependent IgG decline. However, this decline was not associated with an increased risk of antibiotic-treated infections, suggesting a dissociation between total IgG levels and functional immune competence in this cohort. These findings support continued use of rituximab with vigilant monitoring, though dose adjustments may be warranted for patients with rapidly decreasing IgG.

INTRODUCTION: Systemic lupus erythematosus (SLE) is a prototypical autoimmune disorder characterized by production of autoantibodies targeting self-antigens. These autoantibodies form immune-complexes that deposit in various tissues, leading to complement activation, inflammation, and, ultimately, organ damage. The detection of specific autoantibodies is crucial for diagnosing SLE and for assessing disease activity.

AREAS COVERED: A variety of autoantibodies are employed in clinical practice to assess the risk of different SLE manifestations and other systemic inflammatory diseases. These autoantibody specificities are integral to clinical decision-making procedures. Herein, we examine the most commonly evaluated autoantibodies and their associations with disease phenotypes. In addition, we discuss recent findings of novel autoantibodies in SLE and their clinical relevance and potential utility.

EXPERT OPINION: In addition to the well-established autoantibody specificities routinely assessed in clinical practice for patients with a diagnosis of - or clinically suspected - SLE, recent studies have identified several new autoantibodies with potential clinical relevance. If these findings are validated through further research and accessible diagnostic assays are developed, these emerging autoantibodies could narrow the gap between first symptoms and classifiable disease and significantly enhance patient management by providing critical insights into the risk of specific SLE manifestations, thereby facilitating more timely and personalized interventions.

Introduction: Rituximab, a B-cell-depleting therapy, is widely used for multiple sclerosis (MS). While effective, long-term treatment may reduce immunoglobulin G (IgG) levels, potentially increasing infection risk.

Objectives/Aims: This study evaluates IgG dynamics and antibiotic use in MS patients receiving Rituximab in Örebro County, Sweden.

Methods: A retrospective cohort study was conducted on MS patients treated with Rituximab over a 10-year period. Patients included had at least two infusions and a follow-up of ⩾6 months after the last infusion. IgG levels and antibiotic prescriptions were registered longitudinally.

Results: A total of 213 patients (72% female, mean age 40.1 ± 10.6 years) were included, with a mean follow-up time of 44.8 ± 10.6 months. The mean IgG level at treatment initiation was 11.5 ± 2.4 g/L, declining to 10.4 ± 2.3 g/L after the last infusion, with a mean decrease of 1.1 ± 1.4 g/L. Hypogammaglobulinemia (IgG < 6.7 g/L) occurred in 4% of patients. Serum IgG levels demonstrated a significant decline over the course of Rituximab treatment (p < 0.001). However, linear mixed modeling did not detect a statistically significant acceleration over time.

Antibiotic prescriptions were recorded in 63% of patients, with a mean of 2.5 ± 3.3 prescriptions per patient. The most common indications were urinary tract infections (29%) and respiratory tract infections (19%). No significant correlation was found between lower IgG levels and higher antibiotic use.

Conclusion: Rituximab treatment in MS was associated with a significant decline in IgG levels over time. However, the incidence of infections requiring antibiotics did not correlate with IgG decline, suggesting that most patients maintain sufficient immune function. These findings support the continued use of Rituximab in MS while highlighting the need for monitoring IgG levels during long-term treatment.

Introduction: In the last years B-cell depleting therapies such as rituximab (RTX) have become commonplace in the therapeutic landscape of multiple sclerosis (MS), with this class of drugs showing high efficacy. Nevertheless, B-cell depleting therapies have been associated with a higher risk of bacterial infections compared to other disease modifying therapies.

Objectives/Aims: To report the frequency and type of antibiotic prescriptions during a 10-year period.

Methods: A retrospective cohort study was performed on MS-patients followed at Örebro University Hospital (Örebro, Sweden), having received at least one dose of RTX between 2011 and 2020. The number and types of prescribed antibiotic therapies were registered. Data collection was performed using the Swedish MS-registry and electronic patient files. We registered all prescriptions for antibacterial agents between the first dose of RTX administered and 12 months after the last dose, or until the study cut-off date of December 31, 2020, whichever came first.

Results: A total of 219 patients were included (213 with relapsing-remitting MS; mean age 40 years). The median Expanded Disability Status Scale was 2.0. Median disease duration was 36 months at the start of rituximab, median follow-up time was 43 months, and the median number of rituximab infusions was 6. A total of 415 antibiotic prescriptions were registered in this time period. The mean number of prescriptions per patient and year was 0.5. In the cohort, 115 (47%) of the patients did not receive an antibiotic prescription. The most common type of infection treated was urinary tract infections (UTI), followed by upper respiratory tract ones. The majority (83%) of patients who received antibiotic therapy for UTI were women. There were 16 patients (7%) that required long duration of treatment with antibiotics and 15 (7%) of the study population were hospitalized for infections.

Conclusion: Prescription of antibiotics is frequent among MS-patients treated with RTX, occurring in approximately half of this patient population. UTI is the most common cause of antibiotic treatment.

Background: In the diagnostic work up of allergy, determining allergen component-specific immunoglobulin E (IgE) is important for diagnosis, prognosis and choice of treatment.

Objective: The purpose of this study was to evaluate the performance of the immunoblotting assay (Euroline) in detection of IgE antibodies against timothy grass and birch pollen allergen components compared to fluorescent enzyme assay (ImmunoCAP, Phadia 250).

Methods: A total of 128 serum samples from patients allergic to timothy grass and birch pollen were analysed. The levels of IgE antibodies to timothy grass and birch pollen were measured using Euroline DPA-Dx pollen 1 and ImmunoCAP assay. The two methods were then compared on binary (positive vs negative), semi-quantitative (IgE classes) and quantitative (concentration) levels. The two methods were also compared to results from skin prick testing.

Results: The Euroline method showed a positive percentage agreement of 93% and negative percentage agreement of 94% with an overall accuracy of 94% when compared to ImmunoCAP. Kappa analysis showed moderate strength of agreement between the methods in determining IgE classes for 7/11 components tested. All components showed a positive correlation when analysed using Spearman's rank correlation.

Conclusions: Overall, we found that there is good correlation between the Euroline and ImmunoCAP methods in measuring IgE sensitization.

Background:  Patients show varied results to allergen immunotherapy (AIT. The reason for this variability is unclear.

Objective: To describe the relationship between AIT efficacy and demographic characteristics, as well as pre-treatment plasma levels of specific IgE-antibodies to grass and birch pollen.

Methods: A retrospective study was performed based on medical records of 128 patients who received AIT. The patients completed a questionnaire and pre-AIT plasma levels of allergen-specific IgE to grass and birch pollen were measured using EUROLINE DPA-Dx pollen 1 method. Results. Seventy percent of patients classified their allergic symptoms as less severe after AIT. Twenty-seven percent had received AIT targeting only grass pollen, 19% targeting only birch pollen, and 55% targeting both grass and birch. A total of 35 different IgE profiles were found across our study population. On comparison of the demographic characteristics and concentration of allergen-specific IgE-antibodies, no statistically significant differences could be found.

Conclusions: The majority of patients rated their allergic symptoms as less severe after AIT. No clear relationship could be demonstrated between pre-treatment allergen-specific IgE concentration, or demographic characteristics, and effect of AIT. There may be other factors underlying the different responses to AIT.

Uncontrolled release of damage-associated molecular patterns (DAMPs) is suggested to be a major trigger for the dysregulated host immune response that leads to severe COVID-19. Cold-inducible RNA-binding protein (CIRP), is a newly identified DAMP that aggravates inflammation and tissue injury, and induces respiratory failure in sepsis. Whether CIRP contributes to the pathogenesis of respiratory failure in COVID-19 has not yet been explored.

Aim: To investigate if the concentration of extracellular CIRP (eCIRP) in serum associates with respiratory failure and lung involvement by chest computed tomography (CT) in COVID-19.

Methods: Herein we report a prospective observational study of patients with COVID-19 included at two University Hospitals in Sweden between April 2020 and May 2021. Serum from hospitalized patients in Örebro (N=97) were used to assess the association between eCIRP and the level of respiratory support and its correlation with pulmonary involvement on chest CT and inflammatory biomarkers. A cohort of hospitalized and non-hospitalized patients from Umeå (N=78) was used as an external validation cohort. The severity of disease was defined according to the highest degree of respiratory support; mild disease (no oxygen), non-severe hypoxemia (conventional oxygen or high-flow nasal oxygen, HFNO <50% FiO2), and severe hypoxemia (HFNO ≥50% FiO2, mechanical ventilation). Unadjusted and adjusted linear regression was used to evaluate peak eCIRP day 0-4 in respect to severity, age, sex, Charlson comorbidity score, symptom duration, and BMI.

Results: Peak eCIRP concentrations were higher in patients with severe hypoxemia and were independently associated with the degree of respiratory support in both cohorts (Örebro; p=0.01, Umeå; p<0.01). The degree of pulmonary involvement measured by CT correlated with eCIRP, r_s=0.30, p<0.01 (n=97).

Conclusion: High serum levels of eCIRP are associated with acute respiratory failure in COVID-19. Experimental studies are needed to determine if treatments targeting eCIRP reduces the risk of acute respiratory failure in COVID-19.

Soluble B and T lymphocyte attenuator (sBTLA) has been shown to be associated with severity and outcome, in critically ill septic patients. We aimed to assess the dynamic expression of sBTLA, as a prognostic biomarker of long-term mortality in patients with bloodstream infection (BSI) and sepsis, and to evaluate its association with biomarkers indicative of inflammation and immune dysregulation. Secondarily, sBTLA was evaluated in association with severity and bacterial etiology. Patients with BSI (n = 108) were prospectively included, and serially sampled from admission to day 28. Blood and plasma donors (n = 31), sampled twice 28 days apart, served as controls. sBTLA concentration in plasma was determined with enzyme-linked immunosorbent assay. Associations between sBTLA on day 1-2 and 7, and mortality at 90 days and 1 year, were determined with unadjusted, and adjusted Cox regression. Differences related to severity was assessed with linear regression. Mixed model was used to assess sBTLA dynamics over time, and sBTLA associations with bacterial etiology and other biomarkers. sBTLA on day 1-2 and 7 was associated with mortality, in particular failure to normalize sBTLA by day 7 was associated with an increased risk of death before day 90, adjusted HR 17 (95% CI 1.8-160), and one year, adjusted HR 15 (95% CI 2.8-76). sBTLA was positively associated with CRP, and negatively with lymphocyte count. sBTLA on day 1-2 was not linearly associated with baseline SOFA score increase. High SOFA (≥4) was however associated with higher mean sBTLA than SOFA ≤3. sBTLA was not associated with bacterial etiology. We show that sustained elevation of sBTLA one week after hospital admission is associated with late mortality in patients with BSI and sepsis, and that sBTLA concentration is associated with CRP and decreased lymphocyte count. This suggests that sBTLA might be an indicator of sustained immune-dysregulation, and a prognostic tool in sepsis.

Background: Microscopic colitis (MC), comprising lymphocytic colitis (LC) and collagenous colitis (CC), is an inflammatory bowel disorder. MC patients have a lower risk of developing colorectal cancer (CRC) than ulcerative colitis (UC) patients. We hypothesize that the immune response in MC is geared more towards immune surveillance of tumor cells than that of UC, which instead contributes to inflammation-associated CRC.

Methods: Using Luminex, protein levels of 14 immune checkpoints (TIM-3, CD28, CD137, CD27, CD152, HVEM, IDO, LAG-3, BTLA, GITR, CD80, PD-1, PD-L1, PD-L2) in protein lysates from colon biopsies (controls, n = 9; diarrhea controls, n = 7; LC, n = 14; CC, n = 15; UC, n = 17) were analyzed. Soluble checkpoints were analyzed in serum (23 controls, 17 LC, 36 CC and 2 UC).

Results: In patients with active LC and CC, CD137, IDO, and CD80 levels were increased compared with one or both control groups. CD152 and PD-1 levels were increased in patients with active CC compared with both control groups. In patients with active UC, levels of CD137, CD152, BTLA, PD-1, and PD-L2 were increased compared with both control groups, IDO levels were increased compared with controls, and CD80 levels were raised compared with diarrhea controls.

In sera, CD27, IDO, CD80, PD-1, and PD-L2 levels were decreased in LC patients compared to controls.

Conclusions: Increased levels of immune checkpoint molecules in colon biopsies from UC and MC patients are likely a sign of inflammation and may indicate what kind of homeostatic feed-back mechanisms are active to balance inflammation. Lowered concentrations of soluble immune checkpoint molecules in sera from patients with LC indicate a different level of homeostatic balance systemically in LC patients versus controls.