Validation of a risk score to differentiate autoimmune and viral encephalitis: a Nationwide Cohort Study in Denmark.

BACKGROUND: A score to differentiate autoimmune (AE) and viral encephalitis (VE) early upon admission has recently been developed but needed external validation. The objective of this study was to evaluate the performance of the score in a larger and more diagnostically diverse patient cohort. METHODS: We conducted a retrospective nationwide and population-based cohort study including all adults with encephalitis of definite viral (2015-2022) or autoimmune aetiology (2009-2022) in Denmark. Variables included in the score-model were extracted from patient records and individual risk scores were assessed. The performance of the score was assessed by receiver-operating characteristics (ROC) curve analyses and calculation of the area under the curve (AUC). RESULTS: A total of 496 patients with encephalitis [AE n = 90, VE n = 287 and presumed infectious encephalitis (PIE) n = 119] were included in the study. The score was highly accurate in predicting cases of AE reaching an AUC of 0.94 (95% CI 0.92-0.97). Having a score ≥ 3 predicted AE with a PPV of 87% and an NPV of 91%. The risk score was found to perform well across aetiological subgroups and applied to the PIE cohort resulted in an AUC of 0.88 (95% CI 0.84-0.93). CONCLUSION: The excellent performance of the score as reported in the development study was confirmed in this significantly larger and more diverse cohort of patients with encephalitis in Denmark. These results should prompt further prospective testing with wider inclusion criteria.

COVID-19 severity in patients with chronic lymphocytic leukemia treated with venetoclax: a single-center observational cohort study.

Patients with chronic lymphocytic leukemia (CLL) are at high risk of developing severe COVID-19. The present study was undertaken to elucidate COVID-19 related morbidity and mortality in CLL patients treated with venetoclax. We present a single-center study of 108 patients with small lymphocytic lymphoma or CLL treated with venetoclax. Primary outcome was 30-day COVID-19 mortality. Secondary outcomes included COVID-19 severity and hospitalization rate. Forty-eight (44%) patients had PCR-verified SARS-COV-2 between March 2020 and January 2023. Thirty-six patients (75%) presented with asymptomatic/mild COVID-19 and 12 (25%) with severe/critical disease. The hospitalization rate was 46% with a 30-day mortality rate of only 4% and severe comorbidities as the primary cause of death. COVID-19 severity and mortality were similar before and during the Omicron era. High CIRS-scores (P < 0.02) and thrombocytopenia (P < 0.01) were more frequent in patients with severe/critical disease. In real-world data, most venetoclax treated patients presented with mild COVID-19. Hospitalization and mortality rates were low compared to data of general CLL populations. Our data indicate that venetoclax was a safe treatment option for CLL patients during the pandemic.

Longitudinal evaluation of SARS-CoV-2 T cell immunity over 2 years following vaccination and infection.

BACKGROUND: Within a year of the SARS-CoV-2 pandemic, vaccines inducing a robust humoral and cellular immune response were implemented worldwide. However, emergence of novel variants and waning vaccine induced immunity led to implementation of additional vaccine boosters. METHODS: This prospective study evaluated the temporal profile of cellular and serological responses in a cohort of 639 SARS-CoV-2 vaccinated participants, of whom a large proportion experienced a SARS-CoV-2 infection. All participants were infection naïve at the time of their first vaccine dose. Proportions of SARS-CoV-2 Spike-specific T cells were determined after each vaccine dose using the Activation Induced Markers (AIM) assay, while levels of circulating SARS-CoV-2 antibodies were determined by the Meso Scale serology assay. RESULTS: We found a significant increase in SARS-CoV-2 Spike-specific CD4+ and CD8+ T cell responses following the third dose of a SARS-CoV-2 mRNA vaccine as well as enhanced CD8+ T cell responses after the fourth dose. Further, increased age was associated with a poorer response. Finally, we observed that SARS-CoV-2 infection boosts both the cellular and humoral immune response, relative to vaccine-induced immunity alone. CONCLUSION: Our findings highlight the boosting effect on T cell immunity of repeated vaccine administration. The combination of multiple vaccine doses and SARS-CoV-2 infections maintains population T cell immunity although with reduced levels in the elderly.

Rationale and design of NUDGE-FLU-CHRONIC and NUDGE-FLU-2: Two nationwide randomized trials of electronic nudges to increase influenza vaccination among patients with chronic diseases and older adults during the 2023/2024 influenza season.

BACKGROUND: Yearly influenza vaccination is strongly recommended for older adults and patients with chronic diseases including cardiovascular disease (CVD); however, vaccination rates remain suboptimal, particularly among younger patients. Electronic letters incorporating behavioral nudges are highly scalable public health interventions which can potentially increase vaccination, but further research is needed to determine the most effective strategies and to assess effectiveness across different populations. The purpose of NUDGE-FLU-CHRONIC and NUDGE-FLU-2 are to evaluate the effectiveness of electronic nudges delivered via the Danish governmental electronic letter system in increasing influenza vaccination among patients with chronic diseases and older adults, respectively. METHODS: Both trials are designed as pragmatic randomized implementation trials enrolling all Danish citizens in their respective target groups and conducted during the 2023/2024 influenza season. NUDGE-FLU-CHRONIC enrolls patients aged 18-64 years with chronic diseases. NUDGE-FLU-2 builds upon the NUDGE-FLU trial conducted in 2022/2023 and aims to expand the evidence by testing both previously successful and new nudges among adults ≥65 years during a subsequent influenza season. Persons with exemptions from the electronic letter system are excluded from both trials. In both trials, participants are randomized in a 2.45:1:1:1:1:1:1 ratio to either receive no electronic letter (usual care) or to receive one of 6 different behaviorally informed electronic letters. NUDGE-FLU-CHRONIC has randomized 299,881 participants with intervention letters delivered on September 24, 2023, while NUDGE-FLU-2 has randomized 881,373 participants and delivered intervention letters on September 13, 2023. Follow-up is currently ongoing. In both trials, the primary endpoint is receipt of influenza vaccination on or before January 1, 2024, and the secondary endpoint is time to vaccination. Clinical outcomes including respiratory and cardiovascular hospitalizations, all-cause hospitalization, and mortality are included as prespecified exploratory endpoints. Prespecified individual-level pooled analyses will be conducted across NUDGE-FLU, NUDGE-FLU-CHRONIC, and NUDGE-FLU-2. DISCUSSION: NUDGE-FLU-CHRONIC is the first nationwide randomized trial of electronic nudges to increase influenza vaccination conducted among 18-64-year-old high-risk patients with chronic diseases. NUDGE-FLU-2 will provide further evidence on the effectiveness of electronic nudges among older adults ≥65 years. Collectively, the NUDGE-FLU trials will provide an extensive evidence base for future public health communications. TRIAL REGISTRATION: NUDGE-FLU-CHRONIC: Clinicaltrials.gov: NCT06030739, registered September 11, 2023, https://clinicaltrials.gov/study/NCT06030739. NUDGE-FLU-2: Clinicaltrials.gov: NCT06030726, registered September 11, 2023, https://clinicaltrials.gov/study/NCT06030726.

Pulmonary arteriovenous malformations in patients with previous brain abscess: a cross-sectional population-based study.

BACKGROUND AND PURPOSE: Pulmonary arteriovenous malformations (PAVMs) may cause recurrent brain abscess. The primary aim was to determine the prevalence of PAVM amongst survivors of brain abscess. The proportion with cardiac right-to-left shunts was also assessed post hoc. METHODS: This was a cross-sectional population-based study of adult (≥18 years) survivors of cryptogenic bacterial brain abscess in Denmark from 2007 through 2016. Patients were invited for bubble-echocardiography to detect vascular right-to-left shunting and, if abnormal, subsequent computed tomography thorax for diagnosis of PAVM. Data are presented as n/N (%) or median with interquartile range (IQR). RESULTS: Study participation was accepted by 47/157 (30%) eligible patients amongst whom two did not appear for scheduled bubble-echocardiography. The median age of participants was 54 years (IQR 45-62) and 19/57 (33%) were females compared with 59 years (IQR 48-68, p = 0.05) and 41/85 females (48%, p = 0.22) in non-participants. Bubble-echocardiography was suggestive of shunt in 10/45 (22%) participants and PAVM was subsequently confirmed by computed tomography in one patient with grade 1 shunting. The corresponding prevalence of PAVM was 2% (95% confidence interval 0.06-11.8) amongst all examined participants. Another 9/45 (20%) were diagnosed with patent in persistent foramen ovale (n = 8) or atrial septum defect (n = 1), which is comparable with the overall prevalence of 25% amongst adults in the Danish background population. CONCLUSIONS: Undiagnosed PAVM amongst adult survivors of cryptogenic bacterial brain abscess is rare but may be considered in select patients. The prevalence of cardiac right-to-left shunts amongst brain abscess patients corresponds to the prevalence in the general population.

Brain Abscess Caused by Oral Cavity Bacteria: A Nationwide, Population-based Cohort Study.

BACKGROUND: Oral cavity bacteria are the most frequent etiology of brain abscess. Yet, data on the clinical presentation and outcome are scarce. METHODS: We performed a nationwide, population-based study comprising all adults (aged ≥18 years) with brain abscess due to oral cavity bacteria in Denmark from 2007 through 2020. Prognostic factors for unfavorable outcome (Glasgow outcome scale, 1-4) were examined using modified Poisson regression to compute adjusted relative risks (RRs) with 95% confidence intervals (CIs). RESULTS: Among 287 identified patients, the median age was 58 years (interquartile range, 47-66), and 96 of 287 (33%) were female. Preexisting functional impairment was absent or mild in 253 of 280 (90%), and risk factors for brain abscess included immunocompromise in 95 of 287 (33%), dental infection in 68 of 287 (24%), and ear-nose-throat infection in 33 of 287 (12%). Overall, a neurological deficit was present in 246 of 276 (86%) and in combination with headache and fever in 64 of 287 (22%). Identified microorganisms were primarily the Streptococcus anginosus group, Fusobacterium, Actinomyces, and Aggregatibacter spp., and 117 of 287 (41%) were polymicrobial. Unfavorable outcome occurred in 92 of 246 (37%) at 6 months after discharge and was associated with antibiotics before neurosurgery (RR, 3.28; 95% CI, 1.53-7.04), rupture (RR, 1.89; 95% CI, 1.34-2.65), and immunocompromise (RR, 1.80; 95% CI, 1.29-2.51), but not with specific targeted antibiotic regimens. Identified dental infection was associated with favorable prognosis (RR, 0.58; 95% CI, .36-.93). CONCLUSIONS: Brain abscess due to oral cavity bacteria often occurred in previously healthy individuals without predisposing dental infections. Important risk factors for unfavorable outcome were rupture and immunocompromise. However, outcome was not associated with specific antibiotic regimens supporting carbapenem-sparing strategies.

Cancer risk and temporal trends in people with HIV during a quarter of a century - a nationwide population-based matched cohort study.

BACKGROUND: It is important to understand current trends in cancer risk among people living with HIV (PLWH) to improve outcomes and to commission and delivery appropriate services. METHODS: Nationwide, population-based, matched cohort study on all adult PLWH treated at Danish HIV health care centres since 1 January 1995 and a comparison cohort, randomly selected from the background population and matched on sex and date of birth. RESULTS: We included 6327 PLWH and 63,270 individuals in the comparison cohort - 74% were men and median age was 37 (interquartile range: 30-46). For both smoking related cancers, virological cancers and other cancers, incidence was substantially higher in the first year of observation for PLWH than for the remaining observation period. The risk of smoking related cancer remained stably increased throughout the observation period, whereas the relative risk of virological cancers decreased, especially in the first year of follow up. Finally, the risk of other cancers for PLWH decreased to a level below that of the background population during the study period. CONCLUSION: The fact that the risk of other cancers was probably not higher among PLWH than in the comparison cohort is encouraging, as the excess risk of virological and smoking related cancers is potentially preventable by timely treatment of HIV and smoking cessation.

Benign recurrent lymphocytic meningitis (Mollaret's meningitis) in Denmark: a nationwide cohort study.

BACKGROUND AND PURPOSE: Data on clinical features and outcomes of benign recurrent lymphocytic meningitis (BRLM) are limited. METHODS: This was a nationwide population-based cohort study of all adults hospitalized for BRLM associated with herpes simplex virus type 2 (HSV-2) at the departments of infectious diseases in Denmark from 2015 to 2020. Patients with single-episode HSV-2 meningitis were included for comparison. RESULTS: Forty-seven patients with BRLM (mean annual incidence 1.2/1,000,000 adults) and 118 with single-episode HSV-2 meningitis were included. The progression risk from HSV-2 meningitis to BRLM was 22% (95% confidence interval [CI] 15%-30%). The proportion of patients with the triad of headache, neck stiffness and photophobia/hyperacusis was similar between BRLM and single-episode HSV-2 meningitis (16/43 [37%] vs. 46/103 [45%]; p = 0.41), whilst the median cerebrospinal fluid leukocyte count was lower in BRLM (221 cells vs. 398 cells; p = 0.02). Unfavourable functional outcomes (Glasgow Outcome Scale score of 1-4) were less frequent in BRLM at all post-discharge follow-up visits. During the study period, 10 (21%) patients with BRLM were hospitalized for an additional recurrence (annual rate 6%, 95% CI 3%-12%). The hazard ratio for an additional recurrence was 3.93 (95% CI 1.02-15.3) for patients with three or more previous episodes of meningitis. CONCLUSIONS: Clinical features of BRLM were similar to those of single-episode HSV-2 meningitis, whilst post-discharge outcomes were more favourable. Patients with three or more previous episodes of meningitis had higher risk of an additional recurrence.

Ramsay Hunt syndrome and concurrent varicella-zoster virus meningitis in Denmark: A nationwide cohort study.

Ramsay Hunt syndrome (RHS) is a manifestation of reactivated varicella-zoster virus (VZV) from the geniculate ganglion. Data on clinical features and outcomes of patients with RHS and concurrent VZV meningitis (henceforth RHS meningitis) are limited. Thus, we conducted a nationwide population-based cohort study of all adults hospitalized for RHS meningitis at the departments of infectious diseases in Denmark from 2015 to 2020. Patients with VZV meningitis without cranial nerve palsies were included for comparison. In total, 37 patients with RHS meningitis (mean annual incidence: 1.6/1 000 000 adults) and 162 with VZV meningitis without cranial nerve palsies were included. In RHS meningitis, the median age was 52 years (interquartile range: 35-64), and in addition to peripheral facial nerve palsy (100%), dizziness (46%), and hearing loss (35%) were common symptoms. The triad of headache, neck stiffness, and photophobia/hyperacusis was less common in RHS meningitis than in VZV meningitis without cranial nerve palsies (0/27 [0%] vs. 24/143 [17%]; p = 0.02). At 30 days after discharge, 18/36 (50%) patients with RHS meningitis had persistent peripheral facial nerve palsy, with no statistically significant difference between those treated with and without adjuvant glucocorticoids (6/16 [38%] vs. 12/20 [60%]; p = 0.18). Additional sequelae of RHS meningitis included dizziness (29%), neuralgia (14%), tinnitus/hyperacusis (11%), hearing loss (9%), headache (9%), fatigue (6%), and concentration difficulties (3%). In conclusion, clinical features and outcomes of RHS meningitis were primarily related to cranial neuropathies.

Viral lumbosacral radiculitis (Elsberg syndrome) in Denmark.

PURPOSE: To describe clinical features and outcomes of viral lumbosacral radiculitis (Elsberg syndrome). METHODS: Nationwide population-based cohort study of all adults hospitalised for viral lumbosacral radiculitis at departments of infectious diseases in Denmark from 2015 to 2020. RESULTS: Twenty-eight patients with viral lumbosacral radiculitis were included (mean annual incidence: 1.2/1,000,000 adults). The median age was 35 years (IQR 27-43), and 22/28 (79%) were female. All patients had urinary retention, with 17/28 (61%) needing a catheter. On admission, at least one sign or symptom of meningitis (headache, neck stiffness, photophobia/hyperacusis) was present in 18/22 (82%). Concurrent genital herpetic lesions were present in 11/24 (46%). The median cerebrospinal fluid leukocyte count was 153 cells/µL (IQR 31-514). Magnetic resonance imaging showed radiculitis/myelitis in 5/19 (26%). The microbiological diagnosis was herpes simplex virus type 2 in 19/28 (68%), varicella-zoster virus in 2/28 (7%), and unidentified in 7/28 (25%). Aciclovir/valaciclovir was administered in 27/28 (96%). At 30 days after discharge, 3/27 (11%) had persistent urinary retention with need of catheter. At 180 days after discharge, moderate disabilities (Glasgow Outcome Scale score of 4) were observed in 5/25 (20%). CONCLUSIONS: Urinary retention resolved within weeks in most patients with viral lumbosacral radiculitis, but moderate disabilities according to the Glasgow Outcome Scale were common at the end of follow-up.

SARS-CoV-2 vaccine-induced antibodies protect against Omicron breakthrough infection.

SARS-CoV-2 Omicron quickly spread globally, also in regions with high vaccination coverage, emphasizing the importance of exploring the immunological requirements for protection against Omicron breakthrough infection. The test-negative matched case-control study (N = 964) characterized Omicron breakthrough infections in triple-vaccinated individuals from the ENFORCE cohort. Within 60 days before a PCR test spike-specific IgG levels were significantly lower in cases compared to controls (GMR [95% CI] for BA.2: 0.83 [0.73-0.95], p = 0.006). Multivariable logistic regression showed significant associations between high antibody levels and lower odds of infection (aOR [95% CI] for BA.2 spike-specific IgG: 0.65 [0.48-0.88], p = 0.006 and BA.2 ACE2-blocking antibodies: 0.46 [0.30-0.69], p = 0.0002). A sex-stratified analysis showed more pronounced associations for females than males. High levels of vaccine-induced antibodies provide partial protection against Omicron breakthrough infections. This is important knowledge to further characterize a threshold for protection against new variants and to estimate the necessity and timing of booster vaccination.

Omicron Variant-Specific Serological Imprinting Following BA.1 or BA.4/5 Bivalent Vaccination and Previous SARS-CoV-2 Infection: A Cohort Study.

BACKGROUND: Continuous evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outpaces monovalent vaccine cross-protection to new viral variants. Consequently, bivalent coronavirus disease 2019 (COVID-19) vaccines including Omicron antigens were developed. The contrasting immunogenicity of the bivalent vaccines and the impact of prior antigenic exposure on new immune imprinting remains to be clarified. METHODS: In the large prospective ENFORCE cohort, we quantified spike-specific antibodies to 5 Omicron variants (BA.1 to BA.5) before and after BA.1 or BA.4/5 bivalent booster vaccination to compare Omicron variant-specific antibody inductions. We evaluated the impact of previous infection and characterized the dominant antibody responses. RESULTS: Prior to the bivalent fourth vaccine, all participants (N = 1697) had high levels of Omicron-specific antibodies. Antibody levels were significantly higher in individuals with a previous polymerase chain reaction positive (PCR+) infection, particularly for BA.2-specific antibodies (geometric mean ratio [GMR] 6.79, 95% confidence interval [CI] 6.05-7.62). Antibody levels were further significantly boosted in all individuals by receiving either of the bivalent vaccines, but greater fold inductions to all Omicron variants were observed in individuals with no prior infection. The BA.1 bivalent vaccine generated a dominant response toward BA.1 (adjusted GMR 1.31, 95% CI 1.09-1.57) and BA.3 (1.32, 1.09-1.59) antigens in individuals with no prior infection, whereas the BA.4/5 bivalent vaccine generated a dominant response toward BA.2 (0.87, 0.76-0.98), BA.4 (0.85, 0.75-0.97), and BA.5 (0.87, 0.76-0.99) antigens in individuals with a prior infection. CONCLUSIONS: Vaccination and previous infection leave a clear serological imprint that is focused on the variant-specific antigen. Importantly, both bivalent vaccines induce high levels of Omicron variant-specific antibodies, suggesting broad cross-protection of Omicron variants.

Risk of Depression in People With Human Immunodeficiency Virus: A Nationwide Population-based Matched Cohort Study.

BACKGROUND: Human immunodeficiency virus (HIV) infection is associated with depression. However, previous studies have not addressed familial factors. METHODS: Nationwide, population-based, matched cohort study of people with HIV (PWH) in Denmark between 1995 and 2021 who were matched on sex and date of birth with a comparison cohort randomly selected from the Danish population. Family-related factors were examined by inclusion of siblings of those in the cohorts. We calculated hazard ratios (HRs) for depression, receipt of antidepressants, electroconvulsive therapy (ECT), and suicide, as well as the yearly proportions of study cohorts with psychiatric hospital contact due to depression and receipt of antidepressants from 10 years before to 10 years after study inclusion. RESULTS: We included 5943 PWH and 59 430 comparison cohort members. Median age was 38 years, and 25% were women. We observed an increased risk of depression, receipt of antidepressants, ECT, and suicide among PWH in the 2 first years of observation (HR, 3.3; 95% confidence interval [CI]: 2.5-4.4), HR, 3.0 (95% CI: 2.7-3.4), HR, 2.8 (95% CI: .9-8.6), and HR, 10.7 (95% CI: 5.2-22.2), thereafter the risk subsided but remained increased. The proportions of PWH with psychiatric hospital contact due to depression and receipt of antidepressants were increased prior to and especially after HIV diagnosis. Risk of all outcomes was substantially lower among siblings of PWH than among PWH (HR for receipt of antidepressants, 1.1; 95% CI: 1.0-1.2). CONCLUSIONS: PWH have an increased risk of depression. Family-related factors are unlikely to explain this risk.

Group A Streptococcus Meningitis in Adults, Denmark.

We report a 21-fold increase in group A Streptococcus meningitis in adults in Denmark during October 13, 2022-April 12, 2023, concurrent with an outbreak of invasive streptococcal disease. We describe clinical characteristics of the outbreak cases and prognosis for patients in comparison to those for previous sporadic cases.

Association of Self-reported Systemic Reactions Following SARS-CoV-2 Vaccination With Immunological Response in the Danish National Cohort Study of Effectiveness and Safety of SARS-CoV-2 Vaccines (ENFORCE).

Background: Side effects to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines are a key concern contributing to vaccine hesitancy, but more individuals may be encouraged if SARS-CoV-2 vaccines were known to lead to a stronger immune response. Methods: Included were adult participants from the Danish National Cohort Study of Effectiveness and Safety of SARS-CoV-2 Vaccines (ENFORCE) who completed a questionnaire to assess systemic reactions following SARS-CoV-2 vaccination (BTN162b2, mRNA-1273, ChAdOx1) and had SARS-CoV-2 spike immunoglobulin G (IgG) levels measured at baseline and post-vaccine. A symptom score was developed to measure severity of systemic adverse reactions (+1 for each moderate, +2 for each severe). Post-vaccination SARS-CoV-2 spike IgG levels were compared between participants with different scores using multivariable linear regression. Results: A total of 6528 participants were included (56.3% females; median age [interquartile range], 64 [54-75] years). After the first vaccination, no association was found between symptom score and post-vaccine dose spike IgG level (P = .575). Following the second vaccination, significantly higher spike IgG levels were observed according to higher symptom scores (P < .001); adjusted geometric mean ratios were 1.16 (95% CI, 1.04-1.30), 1.24 (95% CI, 1.09-1.41), 1.25 (95% CI, 1.06-1.46), and 1.21 (95% CI, 1.08-1.35), for scores of 2, 3, 4, and ≥5, respectively, compared with a score of 0. After adjustment for pre-vaccine dose spike IgG, this association was attenuated. Conclusions: An association was found between more severe adverse reactions and stronger antibody response after the second vaccination but not the first, likely attributed to higher levels of preexisting immunity gained from response to first vaccination. Regardless of side effects, most people experienced an effective immune response following vaccination.

Impact of age and comorbidities on SARS-CoV-2 vaccine-induced T cell immunity.

BACKGROUND: Older age and chronic disease are important risk factors for developing severe COVID-19. At population level, vaccine-induced immunity substantially reduces the risk of severe COVID-19 disease and hospitalization. However, the relative impact of humoral and cellular immunity on protection from breakthrough infection and severe disease is not fully understood. METHODS: In a study cohort of 655 primarily older study participants (median of 63 years (IQR: 51-72)), we determined serum levels of Spike IgG antibodies using a Multiantigen Serological Assay and quantified the frequency of SARS-CoV-2 Spike-specific CD4 + and CD8 + T cells using activation induced marker assay. This enabled characterization of suboptimal vaccine-induced cellular immunity. The risk factors of being a cellular hypo responder were assessed using logistic regression. Further follow-up of study participants allowed for an evaluation of the impact of T cell immunity on breakthrough infections. RESULTS: We show reduced serological immunity and frequency of CD4 + Spike-specific T cells in the oldest age group (≥75 years) and higher Charlson Comorbidity Index (CCI) categories. Male sex, age group ≥75 years, and CCI > 0 is associated with an increased likelihood of being a cellular hypo-responder while vaccine type is a significant risk factor. Assessing breakthrough infections, no protective effect of T cell immunity is identified. CONCLUSIONS: SARS-CoV-2 Spike-specific immune responses in both the cellular and serological compartment of the adaptive immune system increase with each vaccine dose and are progressively lower with older age and higher prevalence of comorbidities. The findings contribute to the understanding of the vaccine response in individuals with increased risk of severe COVID-19 disease and hospitalization.

Vaccination has proven very effective in protecting against severe disease and hospitalization of people with COVID-19, the disease caused by SARS-CoV-2. It is still unclear, however, how the different components of the immune system respond to SARS-CoV-2 vaccination and protect from infection and severe disease. Two of the most predominant components of the immune system are specialized proteins and cells. The proteins circulate in the blood and help clear the virus by binding to it, while the cells either kill the virus or help other cells to produce more antibodies. Here, we examined the response of these two components to the SARS-CoV-2 vaccine in 655 Danish citizens. The response of both components was lower in people over 75 years old and with other diseases. These findings help in understanding the immune responses following SARS-CoV-2 vaccination in people at increased risk of severe symptoms of COVID-19.

Treatment effect modifiers in hospitalised patients with COVID-19 receiving remdesivir and dexamethasone.

BACKGROUND: The combined effectiveness of remdesivir and dexamethasone in subgroups of hospitalised patients with COVID-19 is poorly investigated. METHODS: In this nationwide retrospective cohort study, we included 3826 patients with COVID-19 hospitalised between February 2020 and April 2021. The primary outcomes were use of invasive mechanical ventilation and 30-day mortality, comparing a cohort treated with remdesivir and dexamethasone with a previous cohort treated without remdesivir and dexamethasone. We used inverse probability of treatment weighting logistic regression to assess associations with progression to invasive mechanical ventilation and 30-day mortality between the two cohorts. The analyses were conducted overall and by subgroups based on patient characteristics. RESULTS: Odds ratio for progression to invasive mechanical ventilation and 30-day mortality in individuals treated with remdesivir and dexamethasone compared to treatment with standard of care alone was 0.46 (95% confidence interval, 0.37-0.57) and 0.47 (95% confidence interval, 0.39-0.56), respectively. The reduced risk of mortality was observed in elderly patients, overweight patients and in patients requiring supplemental oxygen at admission, regardless of sex, comorbidities and symptom duration. CONCLUSIONS: Patients treated with remdesivir and dexamethasone had significantly improved outcomes compared to patients treated with standard of care alone. These effects were observed in most patient subgroups.

Neurosyphilis among people with and without HIV infection: A Danish nationwide prospective, population-based cohort study 2015-2021.

BACKGROUND: Comparative data on clinical presentation, laboratory characteristics, treatment, and outcome of neurosyphilis (NS) in people living with HIV (PLWH) and NS patients without HIV are scarce. METHODS: Nationwide, population-based, prospective cohort study on all adults with NS diagnosed between 2015 and 2021 at departments of infectious diseases in Denmark. RESULTS: We identified 108 patients with NS, which equals a yearly incidence of 0.3/100,000 adults. The median age was 49 years, 85 (79%) were male, 43 (40%) were men having sex with men and 20 (22%) were PLWH. Ninety-five (88%) had early NS, 37 (34%) had ocular or ocular and otogenic NS, and 27 (25%) had symptomatic meningitis. Most common symptoms were visual disturbance (44%), skin rash (40%), fatigue (26%) and chancre (17%). Median CSF leukocyte count was 27 × 106 cells/L. PLWH less often had neurological deficits (p = 0.02). Unfavorable outcome was observed in 23 (21%) at discharge of whom 0 were PLWH (p = 0.01). Among the 88 NS patients without HIV a CSF leukocyte count of ≥ 30 × 106 cells/L was associated with unfavorable outcome (OR = 3.3 (95% confidence interval: 1.1-10.4)). CONCLUSIONS: PLWH with NS have better outcomes than NS patients without HIV infection.

Clinical features and prognostic factors in adults with viral meningitis.

Clinical features applicable to the entire spectrum of viral meningitis are limited, and prognostic factors for adverse outcomes are undetermined. This nationwide population-based prospective cohort study included all adults with presumed and microbiologically confirmed viral meningitis in Denmark from 2015 until 2020. Prognostic factors for an unfavourable outcome (Glasgow Outcome Scale score of 1-4) 30 days after discharge were examined by modified Poisson regression. In total, 1066 episodes of viral meningitis were included, yielding a mean annual incidence of 4.7 episodes per 100 000 persons. Pathogens were enteroviruses in 419/1066 (39%), herpes simplex virus type 2 in 171/1066 (16%), varicella-zoster virus in 162/1066 (15%), miscellaneous viruses in 31/1066 (3%) and remained unidentified in 283/1066 (27%). The median age was 33 years (IQR 27-44), and 576/1066 (54%) were females. In herpes simplex virus type 2 meningitis, 131/171 (77%) were females. Immunosuppression [32/162 (20%)] and shingles [90/149 (60%)] were frequent in varicella-zoster virus meningitis. The triad of headache, neck stiffness and hyperacusis or photophobia was present in 264/960 (28%). The median time until lumbar puncture was 3.0 h (IQR 1.3-7.1), and the median CSF leucocyte count was 160 cells/µl (IQR 60-358). The outcome was unfavourable in 216/1055 (20%) 30 days after discharge. Using unidentified pathogen as the reference, the adjusted relative risk of an unfavourable outcome was 1.34 (95% CI 0.95-1.88) for enteroviruses, 1.55 (95% CI 1.00-2.41) for herpes simplex virus type 2, 1.51 (95% CI 0.98-2.33) for varicella-zoster virus and 1.37 (95% CI 0.61-3.05) for miscellaneous viruses. The adjusted relative risk of an unfavourable outcome was 1.34 (95% CI 1.03-1.75) for females. Timing of acyclovir or valacyclovir was not associated with the outcome in meningitis caused by herpes simplex virus type 2 or varicella-zoster virus. In summary, the outcome of viral meningitis was similar among patients with different aetiologies, including those with presumed viral meningitis but without an identified pathogen. Females had an increased risk of an unfavourable outcome. Early antiviral treatment was not associated with an improved outcome in meningitis caused by herpes simplex virus type 2 or varicella-zoster virus.

Cerebrospinal fluid levels of the macrophage-specific biomarker sCD163 are diagnostic for Lyme neuroborreliosis: An observational cohort study.

OBJECTIVES: We aimed to investigate levels of the macrophage-specific marker, sCD163, in cerebrospinal fluid and plasma in patients with Lyme neuroborreliosis. We tested the diagnostic value of CSF-sCD163 and ReaScan-CXCL13 and analyzed if plasma-sCD163 could monitor treatment response. METHODS: An observational cohort study: Cohort 1-Cerebrospinal fluid from adults with neuroborreliosis (n = 42), bacterial meningitis (n = 16), enteroviral meningitis (n = 29), and controls (n = 33); Cohort 2-Plasma from 23 adults with neuroborreliosis collected at diagnosis, three, and six months. sCD163 was determined using an in-house sandwich ELISA. ReaScan-CXCL13 measured semiquantitative concentrations of CXCL13, cut-off ≥ 250 pg/ml diagnosed neuroborreliosis. Receiver Operating Characteristics analyzed the diagnostic strength. A linear mixed model including follow-up as categorical fixed effect analyzed differences in plasma-sCD163. RESULTS: CSF-sCD163 was higher in neuroborreliosis (643 µg/l) than in enteroviral meningitis (106 µg/l, p < 0.0001) and controls (87 µg/l, p < 0.0001), but not bacterial meningitis (669 µg/l, p = 0.9). The optimal cut-off was 210 µg/l, area under the curve (AUC) 0.85. ReaScan-CXCL13 had an AUC of 0.83. Combining ReaScan-CXCL13 with CSF-sCD163 increased AUC significantly to 0.89. Plasma-sCD163 showed little variation and was not elevated during the 6 months of follow-up. CONCLUSION: CSF-sCD163 is diagnostic for neuroborreliosis with an optimal cut-off of 210 µg/l. Combining ReaScan-CXCL13 with CSF-sCD163 increases AUC. Plasma-sCD163 cannot monitor treatment response.