Cellular and humoral immunogenicity of the mRNA-1273 SARS-CoV-2 vaccine in patients with hematologic malignancies

Recent studies have shown a suboptimal humoral response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger RNA (mRNA) vaccines in patients diagnosed with hematologic malignancies; however, data about cellular immunogenicity are scarce. The aim of this study was to evaluate both the humoral and cellular immunogenicity 1 month after the second dose of the mRNA-1273 vaccine. Antibody titers were measured by using the Elecsys and LIAISON anti–SARS-CoV-2 S assays, and T-cell response was assessed by using interferon-γ release immunoassay technology. Overall, 76.3% (184 of 241) of patients developed humoral immunity, and the cellular response rate was 79% (184 of 233). Hypogammaglobulinemia, lymphopenia, active hematologic treatment, and anti-CD20 therapy during the previous 6 months were associated with an inferior humoral response. Conversely, age >65 years, active disease, lymphopenia, and immunosuppressive treatment of graft-versus-host disease (GVHD) were associated with an impaired cellular response. A significant dissociation between the humoral and cellular responses was observed in patients treated with anti-CD20 therapy (the humoral response was 17.5%, whereas the cellular response was 71.1%). In these patients, B-cell aplasia was confirmed while T-cell counts were preserved. In contrast, humoral response was observed in 77.3% of patients undergoing immunosuppressive treatment of GVHD, whereas only 52.4% had a cellular response. The cellular and humoral responses to the SARS-CoV-2 mRNA-1273 vaccine in patients with hematologic malignancies are highly influenced by the presence of treatments such as anti-CD20 therapy and immunosuppressive agents. This observation has implications for the further management of these patients.The authors also thank the Cellex Foundation for providing research facilities and equipment and the CERCA Programme/Generalitat de Catalunya for institutional support

Epidemiología molecular y caracterización de resistencias antibióticas de Treponema pallidum subespecie pallidum en Barcelona

La sífilis ha causat greus problemes de salut pública al llarg de la seva història i, tot i disposar de la penicilina com a tractament efectiu, aquesta malaltia està reemergent des de les últimes dues dècades. Durant molts anys, el principal obstacle de la investigació de Treponema pallidum subespècie pallidum ha sigut la dificultat de cultivar-lo in vitro. Gràcies als mètodes d'epidemiologia molecular, s'han pogut estudiar la seva diversitat genètica, així com relacionar algunes variants genètiques amb determinades manifestacions clíniques o col·lectius amb conductes sexuals concretes. Aquesta tesi contribueix a ampliar el coneixement existent relatiu a l'epidemiologia molecular i la resistència antibiòtica de Treponema pallidum subespècie pallidum i proporciona, a més, les primeres dades a nivell espanyol. L'estudi es va realitzar a partir de mostres d'úlcera genital i sang procedents de 183 pacients diagnosticats de sífilis precoç a Barcelona durant el 2015. La diversitat genètica d'aquest patogen es va estudiar fent servir els mètodes de tipificació Enhanced CDC Typing i Multilocus Sequence Typing. També es va determinar la presència de mutacions que confereixen resistència a macròlids i de mutacions que confereixen, hipotèticament, resistència a tetraciclines mitjançant la seqüenciació dels gens 23S i 16S de l'ARN ribosomal. Es van identificar diferents variants genètiques de Treponema pallidum subespècie pallidum circulants a Barcelona i les més prevalents van coincidir amb les descrites a altres estudis europeus. Els dos mètodes de tipificació van mostrar rendiments similars, però van presentar diferents avantatges i debilitats quant a la robustesa i objectivitat de les tècniques, al poder discriminador i la disponibilitat de bases de dades públiques. Es va identificar un alt percentatge de resistència a macròlids, fet que ratifica que aquests antibiòtics ja no són recomanables per al tractament alternatiu de la sífilis. En canvi, l'absència de mutacions al gen 16S de l'ARN ribosomal suggereix que no circulen soques resistents a les tetraciclines.La sífilis ha causado graves problemas de salud pública a lo largo de su historia y, a pesar de disponer de la penicilina como tratamiento efectivo, esta enfermedad está reemergiendo desde las últimas dos décadas. Durante muchos años, el principal obstáculo en la investigación de Treponema pallidum subespecie pallidum ha sido la dificultad de su cultivo in vitro. Gracias a los métodos de epidemiología molecular, se ha podido estudiar su diversidad genética, así como relacionar algunas variantes genéticas con determinadas manifestaciones clínicas o colectivos con conductas sexuales concretas. Esta tesis contribuye a ampliar el conocimiento existente relativo a la epidemiología molecular y la resistencia antibiótica de Treponema pallidum subespecie pallidum y proporciona, además, los primeros datos a nivel español. El estudio se realizó a partir de muestras de úlcera genital y sangre procedentes de 183 pacientes diagnosticados de sífilis precoz en Barcelona durante el 2015. La diversidad genética de este patógeno se estudió empleando los métodos de tipificación Enhanced CDC Typing y Multilocus Sequence Typing. También se determinó la presencia de mutaciones que confieren resistencia a macrólidos y de mutaciones que confieren, hipotéticamente, resistencia a tetraciclinas mediante la secuenciación de los genes 23S y 16S del ARN ribosomal. Se identificaron diferentes variantes genéticas de Treponema pallidum subespecie pallidum circulantes en Barcelona y las más prevalentes coincidieron con las descritas en otros estudios europeos. Los dos métodos de tipificación mostraron rendimientos similares, pero presentaron distintas ventajas y debilidades en cuanto a la robustez y objetividad de las técnicas, al poder discriminativo y a la disponibilidad de bases de datos públicas. Se identificó un alto porcentaje de resistencia a macrólidos, lo cual ratifica que estos antibióticos ya no son recomendables para el tratamiento alternativo de la sífilis. En cambio, la ausencia de mutaciones en el gen 16S del ARN ribosomal sugiere que no circulan cepas resistentes a las tetraciclinas.Syphilis has been considered an important public health concern from the past and it is currently in resurgence despite the availability of penicillin as an effective treatment. For many years, the unfeasibility of in vitro culturing of Treponema pallidum subspecies pallidum has been the main difficulty for investigating it. Since 1998, molecular epidemiology tools have led us to study the genetic diversity of this pathogen and to make associations between genetic variants and some clinical manifestations or collectives. This study contributes to further enlarging existing knowledge about the molecular epidemiology and antibiotic resistance of Treponema pallidum subspecies pallidum and provides the first data from Spain. The analyses were performed in genital ulcer and blood specimens from 183 patients diagnosed with early syphilis in Barcelona during 2015. The genetic diversity was studied following the Enhanced CDC Typing and Multilocus Sequence Typing methods. The presence of mutations conferring resistance to macrolides and (hypothetically) to tetracyclines was determined by the sequence analysis of the 23S and 16S ribosomal RNA genes, respectively. Several genetic variants of Treponema pallidum subspecies pallidum were identified, and the most prevalent ones agreed with that described by other European studies. The two typing methods had similar yields, but showed different advantages and weaknesses in terms of discriminatory power, robustness and objectiveness of the techniques, as well as of the availability of public databases. A high percentage of macrolide resistance was identified, supporting that these antibiotics are no longer recommendable for the alternative treatment of syphilis. Instead, the absence of mutations at the 16S ribosomal RNA gene suggests that tetracycline resistant strains are not currently circulating

Multicenter clinical evaluation of a novel multiplex real-time PCR (qPCR) assay for detection of fluoroquinolone resistance in mycoplasma genitalium

Mycoplasma genitalium causes a common sexually transmitted infection with a marked propensity to develop antimicrobial resistance. As few treatment options exist, this poses significant challenges to clinicians. Recent diagnostic advances have resulted in tests that report the simultaneous detection of M. genitalium and any resistance to macrolides, the first-line treatment. This allows for therapy to be tailored to the individual, thereby optimizing treatment outcomes. However, resistance to fluoroquinolones, the second-line treatment, is increasing in M. genitalium In this study, we describe a new assay, MG+parC (beta), which simultaneously reports the detection of M. genitalium and five parC mutations that have been associated with resistance to fluoroquinolones. These mutations affect the amino acid sequence of ParC at residues S83R (A247C), S83I (G248T), D87N (G259A), D87Y (G259T), and D87H (G259C). The study tested the MG+parC (beta) assay with 202 M. genitalium-positive clinical samples from Australia (n = 141) and Spain (n = 61). Compared to Sanger sequencing, the assay performed with a kappa value of 0.985 (95% confidence interval [CI], 0.955 to 1.000), with a mutation detection sensitivity of 97.6% (95% CI, 87.4 to 99.9), and specificity of 100.0% (95% CI, 97.7 to 100.0). Fluoroquinolone resistance-associated mutations in parC targeted by the assay were more prevalent among the Australian cohort (23.4% [95% CI,16.3 to 31.8]) compared to the Spanish population (8.8% [95% CI, 2.9% to 19.3%]) (P = 0.019). The MG+parC (beta) kit is a simple and reliable method for simultaneous detection of M. genitalium and fluoroquinolone resistance-associated mutations in clinical settings. This novel diagnostic tool may extend the utility of the second line of antimicrobial therapies in M. genitalium infection

Label-Free Plasmonic Biosensor for Rapid, Quantitative, and Highly Sensitive COVID-19 Serology : Implementation and Clinical Validation

Serological tests are essential for the control and management of COVID-19 pandemic (diagnostics and surveillance, and epidemiological and immunity studies). We introduce a direct serological biosensor assay employing proprietary technology based on plasmonics, which offers rapid (<15 min) identification and quantification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in clinical samples, without signal amplification. The portable plasmonic device employs a custom-designed multiantigen (RBD peptide and N protein) sensor biochip and reaches detection limits in the low ng mL -1 range employing polyclonal antibodies. It has also been implemented employing the WHO-approved anti-SARS-CoV-2 immunoglobulin standard. A clinical validation with COVID-19 positive and negative samples (n = 120) demonstrates its excellent diagnostic sensitivity (99%) and specificity (100%). This positions our biosensor as an accurate and easy-to-use diagnostics tool for rapid and reliable COVID-19 serology to be employed both at laboratory and decentralized settings for the disease management and for the evaluation of immunological status during vaccination or treatment

Label-Free Plasmonic Biosensor for Rapid, Quantitative, and Highly Sensitive COVID-19 Serology: Implementation and Clinical Validation

Serological tests are essential for the control and management of COVID-19 pandemic, not only for current and historical diagnostics but especially for surveillance, epidemiological, and acquired immunity studies. Clinical COVID-19 serology is routinely performed by enzymatic or chemiluminescence immunoassays (i.e., ELISA or CLIA), which provide good sensitivities at the expense of relatively long turnaround times and specialized laboratory settings. Rapid serological tests, based on lateral flow assays, have also been developed and widely commercialized, but they suffer from limited reliability due to relatively low sensitivity and specificity. We have developed and validated a direct serological biosensor assay employing proprietary technology based on Surface Plasmon Resonance (SPR). The biosensor offers a rapid -less than 15 min- identification and quantification of SARS-CoV-2 antibodies directly in clinical samples, without the need of any signal amplification. The portable plasmonic biosensor device employs a custom-designed multi-antigen sensor biochip, combining the two main viral antigens (RBD peptide and N protein), for simultaneous detection of human antibodies targeting both antigens. The SPR serology assay reaches detection limits in the low ng mL-1 range employing polyclonal antibodies as standard, which are well below the commonly detected antibody levels in COVID-19 patients. The assay has also been implemented employing the first WHO approved anti-SARS-CoV-2 immunoglobulin standard. We have carried out a clinical validation with COVID-19 positive and negative samples (n=120) that demonstrates the excellent diagnostic sensitivity (99%) and specificity (100%). This positions our biosensor device as an accurate, robust, and easy-to-use diagnostics tool for rapid and reliable COVID-19 serology to be employed both at laboratory and decentralized settings for the management of COVID-19 patients and for the evaluation of immunological status during vaccination, treatment or in front of emerging variants.<br /