Untersuchung zur Bestimmung von Risikoparametern für eine Pneumocystis jiroveci-Pneumonie bei nierentransplantierten Patienten und Wirksamkeit einer Standardtherapie mit Trimethopim/Sulfamethoxazol im Vergleich zur Therapie mit Primaquin/Clindamycin

Einleitung: Die Inzidenz von Pneumocystis jirovecii-Pneumonien (PjP) ist bei HIV-Positiven dank effektiver antiretroviraler Therapien in den letzten Dekaden stark zurückgegangen. Dagegen hat sie bei HIV-negativen immunsupprimierten Patienten, wie z.B. Nierentransplantierten deutlich zugenommen. Über Risikoparameter wie eine eingeschränkte Thymusfunktion – gemessen an der Anzahl der CD45RA+CD31+CD4+-T-Lymphozytenzahlen (RTE, recent thymus emigrants) - CD4+-T-Lymphopenie und einen Mangel an Mannose-bindendem Lektin für das Auftreten einer PjP und die Wirksamkeit einer Therapie mit Clindamycin-Primaquin (C-P) verglichen mit der Standardtherapie aus Trimethoprim-Sulfamethoxazol (TMP-SMX) ist bei dieser Patientengruppe wenig bekannt. Methoden: In Studiengruppe A wurden 321 de novo nierentransplantierte Patienten zur seriellen Bestimmung der T-Lymphozyten-Subpopulationen (CD4+, CD8+, RTE) im ersten Jahr nach Transplantation und/oder die MBL-Konzentration im Serum an Tag 30, 90, 180 eingeschlossen; 22/321 Patienten erkrankten an einer PjP. Studiengruppe B umfasste die retrospektive Analyse von 57 nierentransplantierten Patienten, die eine PjP entwickelt hatten und initial entweder mit TMP-SMX oder C-P behandelt worden waren. Ergebnisse: Das Alter der Patienten korrelierte invers mit der Zahl der RTE und der CD4+-T-Lymphozyten. PjP-Patienten hatten signifikant niedrigere CD4+ (p=0,012), CD8+ (p=0,029) und RTE (p=0,004) schon vor Transplantation. Die PjP-Patienten waren älter (p=0,008) und hatten häufiger CMV-Infektionen (p=0,045). In einem multivariaten schrittweisen logistischen Regressionsmodell konnten nur die CD4+-T-Lymphozytenzahl vor Transplantation (OR 0,011, p=0,010) und die akute Abstoßungsreaktion (OR 4,66, p=0,023) als Risikofaktor für eine PjP bestimmt werden. Im Gegensatz dazu zeigten die bestimmten MBL-Konzentrationen in der Gruppe der PjP-Patienten und der Kontrollen keinen Unterschied. Bei der Untersuchung der Wirksamkeit der unterschiedlichen Therapieregime zeigte sich eine etwas höhere Rate an Therapieversagen in der Gruppe der mit C-P behandelten (30,4% vs. 20,6%; p=0,545). Bei Patienten mit schwerer PjP zeigte sich dieser Trend stärker (60% vs. 37,5%; p=0,611). C-P war im Rahmen der Salvagetherapie bei Therapieversagen unter TMP-SMX signifikant schlechter wirksam (p=0,028). Therapielimitierende Nebenwirkungen traten in der Gruppe der mit C-P behandelten Patienten nicht auf, in der Gruppe der TMP-SMX-Patienten entwickelten 17,6% der Patienten medikamentenassoziierte Nebenwirkungen (p=0,071). Schlussfolgerungen: Das PjP-Risiko war mit höherem Lebensalter und gestörter Thymusfunktion sowie einer CD4+-T-Lymphopenie schon zum Zeitpunkt vor Transplantation verbunden. Erniedrigte Serum-MBL-Konzentrationen waren dagegen nicht mit einem höheren Risiko, an einer PjP zu erkranken, verbunden. C-P erwies sich als sichere und gut verträgliche Therapie bei der Behandlung einer PjP bei nierentransplantierten Patienten, wenngleich die Kombination etwas weniger wirksam ist als die Standardtherapie mit TMP-SMX. C-P stellt trotzdem eine gute Behandlungsalternative für Patienten mit Kontraindikationen oder Nebenwirkungen unter der Therapie mit TMP-SMX dar.Introduction: The incidence of Pneumocystis jirovecii pneumonia (PjP) has decreased significantly in HIV-positive patients in recent decades due to effective antiretroviral therapies. In contrast, it has increased in HIV-negative immunosuppressed patients, such as renal transplant recipients. Little is known about risk parameters such as impaired thymic function as measured by CD45RA+CD31+CD4+-T-lymphocyte counts (RTE, recent thymic emigrants) - CD4+-T-lymphopenia and mannose-binding lectin deficiency for the occurrence of PjP and the efficacy of clindamycin-primaquine (C-P) therapy compared with standard trimethoprim-sulfamethoxazole (TMP-SMX) therapy in this patient group. Methods: Study group A included 321 de novo kidney transplant patients for serial determination of T-lymphocyte subpopulations (CD4+, CD8+, RTE) in the first year after transplantation and/or serum MBL concentration at three timepoints; 22/321 patients developed PjP. Study group B included retrospective analysis of 57 kidney transplant patients who developed PjP and were initially treated with either TMP-SMX or C-P. Results: Patient age inversely correlated with RTE and CD4+-T-lymphocyte counts. PjP patients had significantly lower CD4+ (p=0.012), CD8+ (p=0.029) and RTE (p=0.004) even before transplantation. PjP patients were older (p=0.008) and had more frequent CMV infections (p=0.045). In a multivariate stepwise logistic regression model, only pre-transplant CD4+-T-lymphocyte count (OR 0.011, p=0.010) and acute rejection (OR 4.66, p=0.023) could be determined as risk factors for PjP. In contrast, the determined MBL concentrations in the group of PjP patients and controls showed no difference. When examining the efficacy of the different treatment regimens, a slightly higher rate of treatment failure was seen in the group treated with C-P (30.4% vs. 20.6%; p=0.545). This trend was more pronounced in patients with severe PjP (60% vs. 37.5%; p=0.611). C-P was significantly less effective in salvage therapy for treatment failure under TMP-SMX (p=0.028). Therapy-limiting side effects did not occur in the group of patients treated with C-P; in the group of TMP-SMX patients, 17.6% of patients developed drug-associated side effects (p=0.071). Conclusions: The risk of PjP was associated with age and impaired thymic function, as well as CD4+-T lymphopenia already at the time before transplantation. In contrast, lowered serum MBL concentrations were not associated with a higher risk of developing PjP. C-P proved to be a safe and well-tolerated therapy in the treatment of PjP in renal transplant patients, although the combination is somewhat less effective than standard therapy with TMP-SMX. C-P nevertheless represents a good treatment alternative for patients with contraindications or side effects during therapy with TMP-SMX

Human isotype‐dependent inhibitory antibody responses against Mycobacterium tuberculosis

Accumulating evidence from experimental animal models suggests that antibodies play a protective role against tuberculosis (TB). However, little is known about the antibodies generated upon Mycobacterium tuberculosis (MTB) exposure in humans. Here, we performed a molecular and functional characterization of the human B‐cell response to MTB by generating recombinant monoclonal antibodies from single isolated B cells of untreated adult patients with acute pulmonary TB and from MTB‐exposed healthcare workers. The data suggest that the acute plasmablast response to MTB originates from reactivated memory B cells and indicates a mucosal origin. Through functional analyses, we identified MTB inhibitory antibodies against mycobacterial antigens including virulence factors that play important roles in host cell infection. The inhibitory activity of anti‐MTB antibodies was directly linked to their isotype. Monoclonal as well as purified serum IgA antibodies showed MTB blocking activity independently of Fc alpha receptor expression, whereas IgG antibodies promoted the host cell infection. Together, the data provide molecular insights into the human antibody response to MTB and may thereby facilitate the design of protective vaccination strategies

Clinical and virological characteristics of hospitalised COVID-19 patients in a German tertiary care centre during the first wave of the SARS-CoV-2 pandemic: a prospective observational study

Purpose: Adequate patient allocation is pivotal for optimal resource management in strained healthcare systems, and requires detailed knowledge of clinical and virological disease trajectories. The purpose of this work was to identify risk factors associated with need for invasive mechanical ventilation (IMV), to analyse viral kinetics in patients with and without IMV and to provide a comprehensive description of clinical course. Methods: A cohort of 168 hospitalised adult COVID-19 patients enrolled in a prospective observational study at a large European tertiary care centre was analysed. Results: Forty-four per cent (71/161) of patients required invasive mechanical ventilation (IMV). Shorter duration of symptoms before admission (aOR 1.22 per day less, 95% CI 1.10-1.37, p < 0.01) and history of hypertension (aOR 5.55, 95% CI 2.00-16.82, p < 0.01) were associated with need for IMV. Patients on IMV had higher maximal concentrations, slower decline rates, and longer shedding of SARS-CoV-2 than non-IMV patients (33 days, IQR 26-46.75, vs 18 days, IQR 16-46.75, respectively, p < 0.01). Median duration of hospitalisation was 9 days (IQR 6-15.5) for non-IMV and 49.5 days (IQR 36.8-82.5) for IMV patients. Conclusions: Our results indicate a short duration of symptoms before admission as a risk factor for severe disease that merits further investigation and different viral load kinetics in severely affected patients. Median duration of hospitalisation of IMV patients was longer than described for acute respiratory distress syndrome unrelated to COVID-19

Multiancestry analysis of the HLA locus in Alzheimer’s and Parkinson’s diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes

Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson’s disease (PD) and Alzheimer’s disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues

A Mutant D-Fructose-6-Phosphate Aldolase (Ala129Ser) with Improved Affinity towards Dihydroxyacetone for the Synthesis of Polyhydroxylated Compounds

A mutant of D-fructose-6-phosphate aldolase (FSA) of Escherichia coli, FSA A129S, with improved catalytic efficiency towards dihydroxyacetone (DHA), the donor substrate in aldol addition reactions, was explored for synthetic applications. The kcat/KM value for DHA was 17-fold higher with FSA A129S than that with FSA wild type (FSA wt). On the other hand, for hydroxyacetone as donor substrate FSA A129S was found to be 3.5-fold less efficient than FSA wt. Furthermore, FSA A129S also accepted glycolaldehyde (GA) as donor substrate with 3.3-fold lower affinity than FSA wt. This differential selectivity of both FSA wt and FSA A129S for GA makes them complementary biocatalysts allowing a control over donor and acceptor roles, which is particularly useful in carboligation multi-step cascade synthesis of polyhydroxylated complex compounds. Production of the mutant protein was also improved for its convenient use in synthesis. Several carbohydrates and nitrocyclitols were efficiently prepared, demonstrating the versatile potential of FSA A129S as biocatalyst in organic synthesis.JAC acknowledges the French foundation Vaincre Les Maladies Lysosomales for a postdoctoral fellowship. MG and XG acknowledge the I3P-CSIC predoctoral scholarship program. This work was supported by the Spanish MCINN CTQ2009-07359/BQU, La Marató de TV3 foundation (Ref:050931), Generalitat de Catalunya DURSI 2005-SGR-00698 and ESF project COST CM0701. GS acknowledges the Deutsche Forschungsgemeinschaft which supported work of Melanie S. and T.I. through SFB 380/B21. We thank Dr. Natalie Trachtmann and Liliya Malikova for help with cloning of vector pJFfsaA129S-kan.Peer reviewe

Clinical and virological characteristics of hospitalised COVID-19 patients in a German tertiary care centre during the first wave of the SARS-CoV-2 pandemic: a prospective observational study

Purpose!#!Adequate patient allocation is pivotal for optimal resource management in strained healthcare systems, and requires detailed knowledge of clinical and virological disease trajectories. The purpose of this work was to identify risk factors associated with need for invasive mechanical ventilation (IMV), to analyse viral kinetics in patients with and without IMV and to provide a comprehensive description of clinical course.!##!Methods!#!A cohort of 168 hospitalised adult COVID-19 patients enrolled in a prospective observational study at a large European tertiary care centre was analysed.!##!Results!#!Forty-four per cent (71/161) of patients required invasive mechanical ventilation (IMV). Shorter duration of symptoms before admission (aOR 1.22 per day less, 95% CI 1.10-1.37, p &amp;lt; 0.01) and history of hypertension (aOR 5.55, 95% CI 2.00-16.82, p &amp;lt; 0.01) were associated with need for IMV. Patients on IMV had higher maximal concentrations, slower decline rates, and longer shedding of SARS-CoV-2 than non-IMV patients (33 days, IQR 26-46.75, vs 18 days, IQR 16-46.75, respectively, p &amp;lt; 0.01). Median duration of hospitalisation was 9 days (IQR 6-15.5) for non-IMV and 49.5 days (IQR 36.8-82.5) for IMV patients.!##!Conclusions!#!Our results indicate a short duration of symptoms before admission as a risk factor for severe disease that merits further investigation and different viral load kinetics in severely affected patients. Median duration of hospitalisation of IMV patients was longer than described for acute respiratory distress syndrome unrelated to COVID-19

New insights into the genetic etiology of Alzheimer’s disease and related dementias

Characterization of the genetic landscape of Alzheimer’s disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/‘proxy’ AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

New insights into the genetic etiology of Alzheimer’s disease and related dementias

Characterization of the genetic landscape of Alzheimer’s disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/‘proxy’ AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele