Erratum to: Association between Modifiable Risk Factors and Levels of Blood-Based Biomarkers of Alzheimer's and Related Dementias in the Look AHEAD Cohort.

[This corrects the article DOI: 10.14283/jarlife.2024.1.].

Association between Modifiable Risk Factors and Levels of Blood-Based Biomarkers of Alzheimer's and Related Dementias in the Look AHEAD Cohort.

Background: Emerging evidence suggests that a number of factors can influence blood-based biomarker levels for Alzheimer's disease (AD) and Alzheimer's related dementias (ADRD). We examined the associations that demographic and clinical characteristics have with AD/ADRD blood-based biomarker levels in an observational continuation of a clinical trial cohort of older individuals with type 2 diabetes and overweight or obesity. Methods: Participants aged 45-76 years were randomized to a 10-year Intensive Lifestyle Intervention (ILI) or a diabetes support and education (DSE) condition. Stored baseline and end of intervention (8-13 years later) plasma samples were analyzed with the Quanterix Simoa HD-X Analyzer. Changes in Aß42, Aß40, Aß42/Aß40, ptau181, neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP) were evaluated in relation to randomization status, demographic, and clinical characteristics. Results: In a sample of 779 participants from the Look AHEAD cohort, we found significant associations between blood-based biomarkers for AD/ADRD and 15 of 18 demographic (age, gender, race and ethnicity, education) and clinical characteristics (APOE, depression, alcohol use, smoking, body mass index, HbA1c, diabetes duration, diabetes treatment, estimated glomerular filtration rate, hypertension, and history of cardiovascular disease) . Conclusions: Blood-based biomarkers of AD/ADRD are influenced by common demographic and clinical characteristics. These factors should be considered carefully when interpreting these AD/ADRD blood biomarker values for clinical or research purposes.

[Acute hypersensitivity reactions associated with monoclonal antibodies for targeted therapy]. / Akute Überempfindlichkeitsreaktionen auf monoklonale Antikörper zur zielgerichteten Therapie.

The application of biologics such as monoclonal antibodies for targeted therapy may lead to immediate adverse drug reactions with different pathophysiological mechanisms. Some of them are due to the immunogenicity of these drugs and are truly allergic, some of them are non-allergic, some are on-target, and some are off-target. The main example of non-allergic reactions are infusion reactions, mainly induced by cytokine release. They generally occur already at the first application and symptoms may decrease in subsequent applications. Allergic reactions need a preceding sensitization phase and therefore may not occur at first application. However, if the IgE-mediated reaction is due to cross-reactivity, they may occur at the first application of the monoclonal antibody. The management of these reactions depends on their severity and the ultimate need to treat the patient with these drugs.

[Drug-induced angioedema : Focus on bradykinin]. / Arzneimittelassoziierte Angioödeme : Bradykinin im Fokus.

On a pathophysiological level, angioedema can be differentiated into histamine- and bradykinin-mediated types. The prototype drug-associated, bradykinin-mediated form of angioedema is angiotensin-converting enzyme (ACE) inhibitor-induced angioedema. The hypothesized cause is a decrease in bradykinin degradation via ACE inhibition. In this scenario, other bradykinin-degrading enzymes assume major importance. When the effect of these enzymes is also diminished, e. g., due to genetic variants or external factors, compensation for the inhibition of ACE may be insufficient. An increased risk of angioedema has also been reported for other drugs, particularly when prescribed in combination with ACE inhibitors. Here, the suspected cause also relates to the degradation of bradykinin. When angioedema arises within the context of concomitant ACE inhibitor use, additive bradykinin degradation effects may be implicated.

The effects of congenital brain serotonin deficiency on responses to chronic fluoxetine.

The importance of reversing brain serotonin (5-HT) deficiency and promoting hippocampal neurogenesis in the mechanisms of action for antidepressants remain highly controversial. Here we examined the behavioral, neurochemical and neurogenic effects of chronic fluoxetine (FLX) in a mouse model of congenital 5-HT deficiency, the tryptophan hydroxylase 2 (R439H) knock-in (Tph2KI) mouse. Our results demonstrate that congenital 5-HT deficiency prevents a subset of the signature molecular, cellular and behavioral effects of FLX, despite the fact that FLX restores the 5-HT levels of Tph2KI mice to essentially the levels observed in wild-type mice at baseline. These results suggest that inducing supra-physiological levels of 5-HT, not merely reversing 5-HT deficiency, is required for many of the antidepressant-like effects of FLX. We also demonstrate that co-administration of the 5-HT precursor, 5-hydroxytryptophan (5-HTP), along with FLX rescues the novelty suppressed feeding (NSF) anxiolytic-like effect of FLX in Tph2KI mice, despite still failing to induce neurogenesis. Thus, our results indicate that brain 5-HT deficiency reduces the efficacy of FLX and that supplementation with 5-HTP can restore some antidepressant-like responses in the context of 5-HT deficiency. Our findings also suggest that feeding latency reductions in the NSF induced by chronic 5-HT elevation are not mediated by drug-induced increments in neurogenesis in 5-HT-deficient animals. Overall, these findings shed new light on the impact of 5-HT deficiency on responses to FLX and may have important implications for treatment selection in depression and anxiety disorders.

Adatoms and clusters of 3d transition metals on graphene: electronic and magnetic configurations.

We investigate the electronic and magnetic properties of single Fe, Co, and Ni atoms and clusters on monolayer graphene (MLG) on SiC(0001) by means of scanning tunneling microscopy (STM), x-ray absorption spectroscopy, x-ray magnetic circular dichroism (XMCD), and ab initio calculations. STM reveals different adsorption sites for Ni and Co adatoms. XMCD proves Fe and Co adatoms to be paramagnetic and to exhibit an out-of-plane easy axis in agreement with theory. In contrast, we experimentally find a nonmagnetic ground state for Ni monomers while an increasing cluster size leads to sizeable magnetic moments. These observations are well reproduced by our calculations and reveal the importance of hybridization effects and intra-atomic charge transfer for the properties of adatoms and clusters on MLG.

Local gating of an Ir(111) surface resonance by graphene islands.

The influence of graphene islands on the electronic structure of the Ir(111) surface is investigated. Scanning tunneling spectroscopy (STS) indicates the presence of a two-dimensional electron gas with a binding energy of -160 meV and an effective mass of -0.18me underneath single-layer graphene on the Ir(111) surface. Density functional calculations reveal that the STS features are predominantly due to a holelike surface resonance of the Ir(111) substrate. Nanometer-sized graphene islands act as local gates, which shift and confine the surface resonance.

Deficient serotonin neurotransmission and depression-like serotonin biomarker alterations in tryptophan hydroxylase 2 (Tph2) loss-of-function mice.

Probably the foremost hypothesis of depression is the 5-hydroxytryptamine (5-HT, serotonin) deficiency hypothesis. Accordingly, anomalies in putative 5-HT biomarkers have repeatedly been reported in depression patients. However, whether such anomalies in fact reflect deficient central 5-HT neurotransmission remains unresolved. We employed a naturalistic model of 5-HT deficiency, the tryptophan hydroxylase 2 (Tph2) R439H knockin mouse, to address this question. We report that Tph2 knockin mice have reduced basal and stimulated levels of extracellular 5-HT (5-HT(Ext)). Interestingly, cerebrospinal fluid (CSF) 5-hydroxyindoleacetic acid (5-HIAA) and fenfluramine-induced plasma prolactin levels are markedly diminished in the Tph2 knockin mice. These data seemingly confirm that low CSF 5-HIAA and fenfluramine-induced plasma prolactin reflects chronic, endogenous central nervous system (CNS) 5-HT deficiency. Moreover, 5-HT(1A) receptor agonist-induced hypothermia is blunted and frontal cortex 5-HT(2A) receptors are increased in the Tph2 knockin mice. These data likewise parallel core findings in depression, but are usually attributed to anomalies in the respective receptors rather than resulting from CNS 5-HT deficiency. Further, 5-HT(2A) receptor function is enhanced in the Tph2 knockin mice. In contrast, 5-HT(1A) receptor levels and G-protein coupling is normal in Tph2 knockin mice, indicating that the blunted hypothermic response relates directly to the low 5-HT(Ext). Thus, we show that not only low CSF 5-HIAA and a blunted fenfluramine-induced prolactin response, but also blunted 5-HT(1A) agonist-induced hypothermia and increased 5-HT(2A) receptor levels are bona fide biomarkers of chronic, endogenous 5-HT deficiency. Potentially, some of these biomarkers could identify patients likely to have 5-HT deficiency. This could have clinical research utility or even guide pharmacotherapy.

Analysis of cytokine secretion from lymphocytes of patients with hypersensitivity reactions to contaminated heparins.

BACKGROUND: Beginning in 2007, anaphylactoid reactions associated with unfractionated heparin (UFH) occurred and resulted in some fatalities. These reactions were reported to be linked to the complement and contact system activation induced by certain batches of UFH containing the adulterant oversulphated chondroitin sulphate (OSCS). OBJECTIVES: Drug-specific secretion of selected cytokines from peripheral blood mononuclear cells (PBMC) of patients with hypersensitivity reactions to contaminated heparin was compared with the respective in vitro cytokine pattern of individuals with or without hypersensitivity to heparin, different glycosaminoglycans or other drugs. METHODS: Study individuals (n = 13) were classified as follows: patients with hypersensitivity reactions to contaminated (OSCS) heparin (n = 3), noncontaminated heparin (n = 1) or other compounds (n = 3) and patients with ongoing heparin therapy without symptoms of intolerance (n = 2). Four healthy individuals served as controls. PBMC were incubated with six different glycosaminoglycan structures. Drug-specific intracellular interleukin (IL)-5, interferon (IFN)-γ and IL-10 production was investigated by flow cytometry, while secretion of IL-5, IL-2 and IFN-γ was analysed by enzyme-linked immunosorbent assay. RESULTS: PBMC from individuals with hypersensitivity reactions to contaminated heparin secreted considerable amounts of IL-2 in vitro. There was a suggestion that ongoing heparin therapy and the Li-heparin in the vials may have an impact on the lymphocyte reactivity of PBMC. CONCLUSIONS: The in vitro lymphocyte reactivity pattern of PBMC from individuals with hypersensitivity reactions to contaminated heparins was neither typical for an immune-mediated nor for a nonimmune-mediated reaction. Possible effects of heparins in the test system itself may require consideration.

In vitro detection and characterization of drug hypersensitivity using flow cytometry.

BACKGROUND: The lymphocyte transformation test (LTT) is the only in vitro test for detecting drug sensitization at the cellular level irrespective of the reaction's phenotype. However, the LTT includes working with radioactive substances and is considered impracticable for routine laboratory investigation. OBJECTIVE: The aim of this study was to assess drug-specific cytokine production by means of flow cytometry as an alternative nonradioactive approach which may be more appropriate for routine testing and may provide in addition more information about the pathophysiology of the reaction than proliferation-based assays, like the LTT. METHOD: Peripheral blood mononuclear cells of 19 patients were incubated with culprit drugs (n = 28) or irrelevant antigens (n = 10). Ten healthy persons served as controls for all different drugs (n = 15). Intracellular interleukin (IL)-5, interferon (IFN)-gamma and IL-10 production was investigated using flow cytometry. Accuracy of the flow cytometry test system was confirmed using different statistical tests, i.e. receiver operating characteristic curve and Mann-Whitney rank test. In addition, drug-specific secretion of IL-5, IL-2 and IFN-gamma were analysed using enzyme-linked immunosorbent assay (ELISA). RESULTS: Drug-specific cytokine production could be demonstrated in 75% of the patients using flow cytometry and in 79% using ELISA respectively. Combining ELISA and flow cytometry increased the sensitivity to 100%. Analysis of involved T-cell subsets [e.g. CD4(+) or CD8(+); T helper (TH) 1 or TH 2] allowed characterization of the in vitro lymphocyte reactivity pattern. CONCLUSIONS: Analysis of drug-specific cytokine production by means of flow cytometry proved a useful and reliable approach for the in vitro detection and characterization of drug hypersensitivities.

Pharmacovigilance of drug allergy and hypersensitivity using the ENDA-DAHD database and the GALEN platform. The Galenda project.

Nonallergic hypersensitivity and allergic reactions are part of the many different types of adverse drug reactions (ADRs). Databases exist for the collection of ADRs. Spontaneous reporting makes up the core data-generating system of pharmacovigilance, but there is a large under-estimation of allergy/hypersensitivity drug reactions. A specific database is therefore required for drug allergy and hypersensitivity using standard operating procedures (SOPs), as the diagnosis of drug allergy/hypersensitivity is difficult and current pharmacovigilance algorithms are insufficient. Although difficult, the diagnosis of drug allergy/hypersensitivity has been standardized by the European Network for Drug Allergy (ENDA) under the aegis of the European Academy of Allergology and Clinical Immunology and SOPs have been published. Based on ENDA and Global Allergy and Asthma European Network (GA(2)LEN, EU Framework Programme 6) SOPs, a Drug Allergy and Hypersensitivity Database (DAHD((R))) has been established under FileMaker((R)) Pro 9. It is already available online in many different languages and can be accessed using a personal login. GA(2)LEN is a European network of 27 partners (16 countries) and 59 collaborating centres (26 countries), which can coordinate and implement the DAHD across Europe. The GA(2)LEN-ENDA-DAHD platform interacting with a pharmacovigilance network appears to be of great interest for the reporting of allergy/hypersensitivity ADRs in conjunction with other pharmacovigilance instruments.

Label-inconsistent use of sibutramine in spontaneous adverse drug reaction reports in Germany.

In Germany, reports on adverse drug reactions (ADRs) are centrally collected and analyzed by the Federal Institute for Drugs and Medical Devices (BfArM). During routine analysis of ADR reports related to the antiobesity drug sibutramine, we repeatedly observed descriptions of its label*-inconsistent use (*European Summary of Product Characteristics (SmPC)). In order to quantify this observation, we analyzed all sibutramine-related ADR reports received by the BfArM so far. Using the same data source, we further analyzed the effect of a Dear Doctor Letter (DDL) which was distributed in 2002 in order to reinforce the label-consistent use of sibutramine. Out of a total of 170 identified reports, 104 were considered as suitable for further analysis. Of these, applying a catalogue of 24 SmPC-derived criteria, 34% (35 reports) contained information indicative of label-inconsistent use. The individual SmPC-criteria most often violated were (% of total analyzed reports): the recommended starting dose of 10 mg/day (9%), the body mass index (BMI)-related threshold permitting drug therapy (6%), and the contraindicated "history of drug abuse" (6%). The DDL was ineffective. The observed percentage of ADR reports, indicating a label-inconsistent use of sibutramine, is considered a signal for a therapeutic risk. This signal should be addressed in a drug utilization study investigating the use of sibutramine by means of a representative patient sample.

Regulation of cAMP by the p75 neurotrophin receptor: insight into drug design of selective phosphodiesterase inhibitors.

Subcellular compartmentalization of PDEs (phosphodiesterases) is a major mechanism for the regulation of cAMP signalling. The identification of the proteins that recruit specific PDE isoforms to subcellular compartments can shed light on the regulation of spatial and temporal cAMP gradients in living cells and provide novel therapeutic targets for inhibiting functions of PDEs. We showed recently that p75(NTR) (p75 neurotrophin receptor) interacts directly with a single PDE isoform, namely PDE4A4/5, via binding to its unique C-terminal region, and targets cAMP degradation to the membrane. The purpose of this review is to present the biological significance of PDE4A compartmentalization by p75(NTR) and discuss the potential of inhibiting the interaction between p75(NTR) and PDE4A for the development of an isoform-specific inhihibitor for PDEs.

Anaphylaxis and toxic epidermal necrolysis or Stevens-Johnson syndrome after nonmucosal topical drug application: fact or fiction?

BACKGROUND: Drug-induced anaphylaxis and toxic epidermal necrolysis (TEN) or Stevens-Johnson syndrome (SJS) represent severe immediate and delayed-type adverse drug reactions (ADRs), respectively. Occurrence of such reactions after topical drug application has only rarely been reported. Hence, we compiled a large number of such cases which we systematically analyzed. METHODS: All such cases contained in the ADR database of the competent pharmacovigilance authority in Germany and cases reported in literature were identified, evaluated and analyzed with regard to potential risk factors. Since the application of drugs to mucous membranes facilitates their entry to the systemic circulation only cases occurring after non-mucosal topical drug application were considered. RESULTS: After evaluation 28 anaphylaxis database cases and 48 anaphylaxis literature cases remained for analysis. Application to skin wounds or to skin with impaired barrier function was identified as a risk factor in 10/28 (36%) of the database cases and in 42/48 (88%) of the literature cases. In 9/28 database cases (32%), anaphylaxis was induced by drugs used for their hyperemizing effect and, in 8/28 cases (29%) by antibiotics or antiseptics. In the literature cases, anaphylaxis was induced by antibiotics or antiseptics in 35/48 cases (73%). Only one SJS database case and one TEN literature case remained after case evaluation. CONCLUSION: Anaphylaxis does occur after non-mucosal topical drug administration. Application of drugs to skin wounds or to skin with impaired barrier function may pose a risk factor for its occurrence. TEN or SJS following non-mucosal topical drug application seems to be extremely rare.

Seizure focus affects regional language networks assessed by fMRI.

OBJECTIVE: To investigate the degree of language dominance in patients with left and right hemisphere seizure foci compared to normal volunteers using a fMRI reading comprehension task. METHODS: Fifty patients with complex partial epilepsy, aged 8 to 56 years and 33 normal volunteers, aged 7 to 34 had fMRI (1.5 T) and neuropsychological testing. Participants silently named an object described by a sentence compared to a visual control. Data were analyzed with region of interest (ROI) analysis based on t maps for inferior frontal gyrus (IFG), midfrontal gyrus (MFG), and Wernicke area (WA). Regional asymmetry indices (AIs) were calculated [(L - R)/(L + R)]; AI > 0.20 was deemed left dominant and AI < 0.20 as atypical language. RESULTS: Left hemisphere focus patients had a higher likelihood of atypical language than right hemisphere focus patients (21% vs 0%, chi2 < 0.002). Left hemisphere focus patients, excluding those with atypical language, had lower regional AI in IFG, MFG, and WA than controls. Right hemisphere focus patients were all left language dominant and had a lower AI than controls in WA and MFG, but not for IFG. AI in MFG and WA were similar between left hemisphere focus/left language patients and right hemisphere focus patients. Patients activated more voxels than healthy volunteers. Lower AIs were attributable to greater activation in right homologous regions. Less activation in the right-side WA correlated with better verbal memory performance in right focus/left hemisphere-dominant patients, whereas less strongly lateralized activation in IFG correlated better with Verbal IQ in left focus/left hemisphere-dominant patients. CONCLUSIONS: Patients had lower asymmetry indices than healthy controls, reflecting increased recruitment of homologous right hemisphere areas for language processing. Greater right hemisphere activation may reflect greater cognitive effort in patient populations, the effect of epilepsy, or its treatment. Regional activation patterns reflect adaptive efforts at recruiting more widespread language processing networks that are differentially affected based on hemisphere of seizure focus.

In vitro analysis of birch-pollen-associated food allergy by use of recombinant allergens in the basophil activation test.

BACKGROUND: Basophil activation is associated with the expression of CD63. In birch-pollen-associated food allergy to celery, carrot and apple, Bet v 1, Api g 1, Dau c 1 and Mal d 1 are major allergens. Recombinant allergens have not yet been used in the CD63-based basophil activation test (BAT). OBJECTIVE: To evaluate the feasibility of using recombinant allergens in the BAT in the diagnosis of allergy to apple, carrot and celery and to compare results with routine tests, i.e. skin prick tests (SPTs) and specific IgE. METHODS: Thirty-two patients with an oral allergy syndrome induced by apple, carrot or celery and 22 controls were studied. SPTs were performed with native foods. Specific IgE was determined by the CAP method and basophil activation by flowcytometry upon double staining with anti-IgE/anti-CD63 monoclonal antibodies after incubating with purified recombinant Bet v 1, Bet v 2, Api g 1, Dau c 1 and Mal d 1. RESULTS: By the combined use of the BAT and the CAP method, sensitization to Bet v 1 and Bet v 2 was detected in 100 and 25% of all subjects, respectively. Sensitivity of specific IgE for apple, carrot and celery was 60, 70 and 75% with corresponding specificities of 64, 86 and 82%. Sensitivity of the BAT for Mal d 1, Dau c 1 and Api g 1 was 75, 65 and 75% with corresponding specificities of 68, 100 and 77%. CONCLUSIONS: The BAT using recombinant allergens provides a valuable new in vitro method for the detection of sensitization to foods. Although double-blind placebo-controlled food challenges remain the gold standard to confirm food allergy, the CD63-based BAT with recombinant allergens may supplement routine tests for allergy diagnosis.

[Drug allergies. Clinical aspects, pathophysiology and treatment of cutaneous manifestations]. / Arzneimittelallergien. Klinik, Pathophysiologie und Therapie kutaner Manifestationsformen.

Cutaneous adverse drug reactions (ADR) are common and encompass a broad clinical spectrum. Since the skin acts as a signaling organ for ADR, the dermatologist plays a key role in their diagnosis. Only a minor part of cutaneous ADR are due to underlying allergic mechanisms. Among these, delayed-type reactions such as maculopapular exanthems and immediate-type reactions such as urticaria and angioedema predominate. Risk factors for the development of cutaneous allergic ADR may be related to the patient (e.g. certain HLA-types), the drug (e.g. its reactivity), and underlying conditions (e.g. viral infections). Antibiotics, non-steroidal anti-inflammatory agents and anticonvulsive medications are most often reported to be causally related.

Combined in vivo and in vitro approach for the characterization of penicillin-specific polyclonal lymphocyte reactivity: tolerance tests with safe penicillins instead of challenge with culprit drugs.

BACKGROUND: Amino-penicillins are a major cause of delayed-type reactions to penicillins. OBJECTIVES: The aim of this study was to establish a diagnostic approach for the characterization of the individual penicillin-specific polyclonal lymphocyte reactivity in order to detect side chain-specific sensitization to amino-penicillins. Patients can then be advised to undergo a tolerance test with safe penicillins instead of provocation with culprit penicillins for confirmation of penicillin allergy. METHODS: We investigated penicillin-specific polyclonal lymphocyte reactivity in nine patients with delayed-type reactions to amino-penicillins by a combined in vivo (patch, prick and intracutaneous tests with delayed readings) and in vitro (lymphocyte transformation test, LTT) approach. RESULTS: A combination of LTT and skin tests improved the sensitivity for the characterization of penicillin-specific polyclonal lymphocyte reactivity and allowed the detection of three different patterns of lymphocyte reactivity. Four patients showed a side chain-specific sensitization to amino-penicillins in vivo and in vitro and were advised to undergo tolerance tests with safe penicillins. Two patients agreed and were exposed to parenteral benzyl-penicillin and oral phenoxymethyl-penicillin which they tolerated without complications. CONCLUSIONS: These data suggest that a combined in vivo and in vitro approach is helpful for the detection of side chain-specific sensitization to amino-penicillins. Patients with such sensitization are very likely to tolerate safe penicillins, thereby expanding their therapeutic options when antibiotic treatment is required.