Harmonized D-dimer levels upon admission for prognosis of COVID-19 severity: Results from a Spanish multicenter registry (BIOCOVID-Spain study).

Coagulopathy is a key feature of COVID-19 and D-dimer has been reported as a predictor of severity. However, because D-dimer test results vary considerably among assays, resolving harmonization issues is fundamental to translate findings into clinical practice. In this retrospective multicenter study (BIOCOVID study), we aimed to analyze the value of harmonized D-dimer levels upon admission for the prediction of in-hospital mortality in COVID-19 patients. All-cause in-hospital mortality was defined as endpoint. For harmonization of D-dimer levels, we designed a model based on the transformation of method-specific regression lines to a reference regression line. The ability of D-dimer for prediction of death was explored by receiver operating characteristic curves analysis and the association with the endpoint by Cox regression analysis. Study population included 2663 patients. In-hospital mortality rate was 14.3%. Harmonized D-dimer upon admission yielded an area under the curve of 0.66, with an optimal cut-off value of 0.945 mg/L FEU. Patients with harmonized D-dimer ≥ 0.945 mg/L FEU had a higher mortality rate (22.4% vs. 9.2%; p < 0.001). D-dimer was an independent predictor of in-hospital mortality, with an adjusted hazard ratio of 1.709. This is the first study in which a harmonization approach was performed to assure comparability of D-dimer levels measured by different assays. Elevated D-dimer levels upon admission were associated with a greater risk of in-hospital mortality among COVID-19 patients, but had limited performance as prognostic test.

Cardiac troponin and COVID-19 severity: Results from BIOCOVID study.

BACKGROUND: Myocardial injury is a common finding in COVID-19 strongly associated with severity. We analysed the prevalence and prognostic utility of myocardial injury, characterized by elevated cardiac troponin, in a large population of COVID-19 patients, and further evaluated separately the role of troponin T and I. METHODS: This is a multicentre, retrospective observational study enrolling patients with laboratory-confirmed COVID-19 who were hospitalized in 32 Spanish hospitals. Elevated troponin levels were defined as values above the sex-specific 99th percentile upper reference limit, as recommended by international guidelines. Thirty-day mortality was defined as endpoint. RESULTS: A total of 1280 COVID-19 patients were included in this study, of whom 187 (14.6%) died during the hospitalization. Using a nonspecific sex cut-off, elevated troponin levels were found in 344 patients (26.9%), increasing to 384 (30.0%) when a sex-specific cut-off was used. This prevalence was significantly higher (42.9% vs 21.9%; P < .001) in patients in whom troponin T was measured in comparison with troponin I. Sex-specific elevated troponin levels were significantly associated with 30-day mortality, with adjusted odds ratios (ORs) of 3.00 for total population, 3.20 for cardiac troponin T and 3.69 for cardiac troponin I. CONCLUSION: In this multicentre study, myocardial injury was a common finding in COVID-19 patients. Its prevalence increased when a sex-specific cut-off and cardiac troponin T were used. Elevated troponin was an independent predictor of 30-day mortality, irrespective of cardiac troponin assay and cut-offs to detect myocardial injury. Hence, the early measurement of cardiac troponin may be useful for risk stratification in COVID-19.

Characteristics and laboratory findings on admission to the emergency department among 2873 hospitalized patients with COVID-19: the impact of adjusted laboratory tests in multicenter studies. A multicenter study in Spain (BIOCOVID-Spain study).

Identification of predictors for severe disease progression is key for risk stratification in COVID-19 patients. We aimed to describe the main characteristics and identify the early predictors for severe outcomes among hospitalized patients with COVID-19 in Spain. This was an observational, retrospective cohort study (BIOCOVID-Spain study) including COVID-19 patients admitted to 32 Spanish hospitals. Demographics, comorbidities and laboratory tests were collected. Outcome was in-hospital mortality. For analysis, laboratory tests values were previously adjusted to assure the comparability of results among participants. Cox regression was performed to identify predictors. Study population included 2873 hospitalized COVID-19 patients. Nine variables were independent predictors for in-hospital mortality, including creatinine (Hazard ratio [HR]:1.327; 95% Confidence Interval [CI]: 1.040-1.695, p = .023), troponin (HR: 2.150; 95% CI: 1.155-4.001; p = .016), platelet count (HR: 0.994; 95% CI: 0.989-0.998; p = .004) and C-reactive protein (HR: 1.037; 95% CI: 1.006-1.068; p = .019). This is the first multicenter study in which an effort was carried out to adjust the results of laboratory tests measured with different methodologies to guarantee their comparability. We reported a comprehensive information about characteristics in a large cohort of hospitalized COVID-19 patients, focusing on the analytical features. Our findings may help to identify patients early at a higher risk for an adverse outcome.

White blood cell count and total protein concentration to predict the absence of microcrystals in synovial fluid.

BACKGROUND: Synovial fluid analysis is essential for diagnosing crystal-induced arthritis. Monosodium urate monohydrate (MSU) crystals in gout and calcium pyrophosphate dihydrate (CPP) crystals in pseudogout trigger inflammatory reactions that result in white blood cell (WBC) activation. This study aimed to evaluate the predictive value of synovial fluid WBC count and total protein concentration for the absence of microcrystals. MATERIALS AND METHODS: This prospective study analyzed all synovial fluid samples collected at a single center in a 6-month period. The absolute WBC count and total protein concentration were recorded for each sample. A single expert used polarized light microscopy to detect microcrystals. Mann-Whitney U-tests was used to compare mean counts and concentrations in samples with and without crystals. Diagnostic performance was assessed through the area under the receiver-operating characteristic curve (AUC). RESULTS: A total of 205 samples were included. The absolute WBC count was significantly higher in samples with crystals than in those without. No differences were found between MSU and CPP. The ROC curve showed an AUC 0.773, and an absolute WBC count <1650/mm3 yielded 95.7% sensitivity, 53.1% specificity, and 97.7% negative predictive value for predicting the absence of microcrystals. Total protein concentration was not significantly different between samples with and without crystals. CONCLUSION: The WBC count is useful for screening for the absence of microcrystals in synovial fluid; the cutoff <1650 WBC/mm3 accurately predicts the absence of crystals, obviating the need for polarized light microscopy and thus simplifying and shortening laboratory analysis of synovial fluid, leading to a reduction in laboratory turnaround time.

Papel central del laboratorio en el diagnóstico de un caso de infiltración de sistema nervioso central por mieloma múltiple refractario / Central role of the laboratory in the diagnosis of a case of central nervous system infiltration by refractory multiple myeloma

La infiltración leptomeníngea en el mieloma múltiple es una complicación poco frecuente y grave que se presenta generalmente tras recaídas de la enfermedad. Para establecer un correcto diagnóstico es necesario demostrar por citología la presencia de células plasmáticas clonales en el líquido cefalorraquídeo. Desde el laboratorio clínico detectamos esta complicación en una paciente diagnosticada de mieloma múltiple refractario, tras analizar una muestra de líquido cefalorraquídeo. La paciente presentaba diversos síntomas neurológicos como incontinencia fecal y disminución de la movilidad en ambas extremidades inferiores. Inicialmente observamos en el líquido pleocitosis, proteinorraquia y niveles elevados de células de alta fluorescencia, asociadas en ocasiones a células malignas. El proteinograma e inmunofijación del líquido confirmó la presencia del componente monoclonal ya detectado en sangre, y tras procesar la muestra por citometría de flujo pudimos confirmar la infiltración de células plasmáticas malignas en el sistema nervioso central. Nuestro laboratorio desempeñó un papel central y esencial en el diagnóstico de esta infrecuente complicación, mediante el uso combinado del proteinograma, la inmunofijación, la citometría de flujo y el autoanalizador hematológico, incluyendo en este último las células de alta fluorescencia, prometedor biomarcador en el cribado de la presencia de células tumorales en líquidos biológicos

Leptomeningeal involvement in multiple myeloma is a rare and serious complication that usually occurs after relapses of the disease. To establish a correct diagnosis, it is necessary to demonstrate, by cytology, the presence of clonal plasma cells in the cerebrospinal fluid. The clinical laboratory detected this complication in a patient diagnosed with refractory multiple myeloma after analysing a cerebrospinal fluid sample. The patient suffered from several neurological symptoms, such as faecal incontinence and lower limb mobility limitation. Pleocytosis and proteinorachia was initially observed, along with high levels of high-fluorescence cells, which are sometimes associated with malignant cells. The protein electrophoresis and immunofixation of the cerebrospinal fluid confirmed the presence of the monoclonal component, already detected in blood. After processing the sample by flow cytometry it was confirmed that there was infiltration of malignant plasma cells in the central nervous system. This laboratory played a central and essential role in the diagnosis of this uncommon complication, by the combined use of protein electrophoresis, immunofixation, flow cytometry, and the haematology autoanalyser. This latter included the high fluorescence cells as a promising biomarker in the screening for the presence of tumour cells in biological fluids

Gamma heavy-chain disease accompanied with follicular lymphoma: a case report.

Heavy chain diseases (HCD) are B-cell lymphoprolipherative disorders characterized by the production of monoclonal heavy chains without associated light chains. Some cases of gamma-HCD (γ-HCD) are concurrent with other lymphoid neoplasm. The monoclonal component is not always detectable by serum electrophoresis, and often an immunofixation procedure is necessary to detect this component. Prognosis is variable, and no established guidelines for follow-up are available. We describe a case of a challenging diagnosis of γ-HCD due to the absence of clinical signs frequently reported in the disease (anaemia and palatal oedema among others). Haematological malignancy was the first suspicion but bone marrow examination was negative. In addition, the presence of an autoimmune bicytopenia and a Klinefelter syndrome complicated the clinical context of the patient. A thoracoabdominal computed tomography reported many small adenopathies whose pathological and immunohystochemical study revealed a follicular lymphoma. Shortly after, serum inmunofixation secondary to an abnormal electrophoretic pattern revealed a gamma paraprotein without light chains. Eventually, γ-HCD in association with follicular lymphoma was the final diagnosis. This is the first case reporting this association.

Evaluation of biological fluid analysis using the sysmex XN automatic hematology analyzer.

BACKGROUND: Hematological cytometers with a biological fluid module could potentially correct the limitations of the manual chamber method. This study evaluates the agreement between the manual technique and the Sysmex XN-1000 analyzer for white blood cell (WBC) and red blood cell (RBC) counts, as well as for leukocyte differentiation in different types of fluids. This study also evaluates the advantages of incorporating the technique in routine laboratory work. METHODS: One hundred and three fluid samples examined were 45 ascite (AF), 21 synovial (SF), 33 pleural (PF), and 31 cerebrospinal (CSF) fluid samples. All cell counting was performed with a Sysmex XN-1000 and a Fuchs-Rosenthal counting chamber. May Gründwald-Giemsa stain was used for manual WBC differentiation. The manual analysis data were obtained in duplicate by the same two observers. Passing-Bablok regression and the Kappa index were used to evaluate the interchangeability and concordance. RESULTS: Good agreement was observed for WBC differentiation in all fluids and for WBC counts in SF and PF. An optimal Kappa index was obtained, which indicated agreement and clinical significance for WBC and RBC counts in CSF and for RBC counts in PF. There was disagreement for WBC and RBC analysis in AF, with significantly higher results from the Sysmex XN-1000 than from the manual method. A reduction in laboratory response time was observed when using the automatic method. CONCLUSIONS: Except for AF, the Sysmex XN-1000 results agree with those of the manual method, although to different degrees depending on the fluid type. © 2017 International Clinical Cytometry Society.

An analysis of the association between genotype and antimicrobial resistance in methicillin-resistant Staphylococcus aureus clinical isolates / Análisis de la asociación entre genotipos y resistencia a múltiples antimicrobianos en aislados de Staphylococcus aureus resistente a meticilina

Genotyping methods are useful resources for the surveillance, detection, prevention and control of multidrug-resistant nosocomial agents, such as methicillin-resistant Staphylococcus aureus (MRSA). An understanding of the association between genotype and antibiotic susceptibility in MRSA clones may be useful in the surveillance of MRSA and to avoid inappropriate treatment future resistance. We genotyped MRSA clinical isolates from the Extremadura region of Spain using pulsed field electrophoresis (PFGE) and analyzed the spectrum of antibiotic susceptibility for each isolate to determine whether resistance is associated with specific genotypes. PFGE revealed six major genotypes: E8a (25%), E7b (17%), E7a (12%), E8B (8%), E10 (6%), and E20 (4%). Isolates with the genotypes E8a and E10 exhibit higher resistance ratios for levofloxacin than isolates with the other major pulsotypes. Similar results were obtained for isolates with the E20 pulsotype with respect to mupirocin. Although we identified no vancomycin-, tigecycline-, linezolid- or daptomycin-resistant strains, we observed significant differences in the mean MIC values obtained for some of these drugs among the major genotypes. Specifically, isolates with the E7b, E8b, and E20 genotypes have significantly higher MICs of tigecycline, vancomycin and linezolid, respectively, than the most sensitive pulsotypes. Isolates with the E8b profile also exhibit a significantly higher rate of reduced vancomycin susceptibility (RVS) (i.e., MIC between 1 and 2 mg/L) than clones with the E10 and E8a profiles. In conclusion, we report associations between genotype and antibiotic sensitivity that should be considered in programs for monitoring and controlling MRSA in health care settings (AU)

Los métodos de genotipaje son un recurso útil para la vigilancia, detención, prevención y control de agentes nosocomiales con multirresistencia antibiótica, como es Staphylococcus aureus resistente a meticilina (SARM). Nuestro grupo lleva a cabo el genotipaje mediante Electroforesis en Campo Pulsado (PFGE) de cepas SARM productoras de infección en la región de Extremadura (España), y realiza un estudio de asociación de los clones obtenidos, con respecto a la sensibilidad antibiótica mostrada por las cepas genotipadas, con el objetivo de conocer si existen resistencias que puedan asociarse específicamente a genotipos concretos. PFGE revela la existencia de 6 genotipos mayoritarios: E8a (25%), E7b (17%), E7a (12%), E8b (8%), E10 (6%), E20 (4%). A través del test Exacto de Fisher determinamos que los genotipos E8a y E10 se inclinan hacia ratios de resistencia mayores para levofloxacino en comparación a los mostrados por otros pulsotipos mayoritarios. De manera análoga ocurre para el pulsotipo E20 con mupirocina. Aunque no se encuentran cepas resistentes para vancomicina, tigeciclina, linezolid y daptomicina, encontramos en los tres primeros, diferencias significativas en el valor medio de CMI obtenido en los diferentes genotipos mayoritarios. Concretamente E7b, E8b y E20 presentan CMI significativamente más altas con respecto a tigeciclina, vancomicina y linezolid, respectivamente, en relación a los pulsotipos más sensibles. Además el perfil E8b muestra un mayor número de cepas con sensibilidad disminuida a vancomicina (SDV) (CMI entre 1 y 2 mg/L) que los clones E10 y E8a, de manera significativa. Creemos que esta información puede resultar útil en la vigilancia de la sensibilidad antibiótica de SARM en nuestro medio, para evitar tratamientos inadecuados y/o futuras resistencias (AU)

Situación actual de la infección por Staphylococcus aureus resistente a meticilina en Extremadura: sensibilidad, clonalidad, y protagonismo de la adquisición extrahospitalaria / State of infection caused by methicillin-resistant Staphylococcus aureus (MRSA) in Extremadura: susceptibility, clonality and role of community-associated MRSA

La correcta vigilancia y control de la infección por Staphylococcus aureus resistente a meticilina (SARM) pasa por el conocimiento actualizado de las propiedades específicas que la caracterizan en cada lugar. El objetivo de este trabajo es describir las características actuales de la infección por SARM en Extremadura. Durante el año 2010 se recogieron 309 SARM, procedentes de muestras clínicas en nuestra comunidad. A cada uno de los aislados se le realizó un estudio de sensibilidad que engloba 17 antibióticos, ensayados mediante tarjeta AST-588 Vitek 2® y método E-test. Además se genotipa mediante Electroforesis en Campo Pulsado (PFGE) una muestra de 100 cepas, escogidas por muestreo aleatorio estratificado. Se obtienen los siguientes resultados: la prevalencia de SARM en Extremadura es 20,2%. Don Benito-Villanueva es el área con mayor prevalencia y una de las de mayor incidencia. Mérida presenta la situación más favorable, con ratios relativamente bajos de prevalencia e incidencia. La adquisición extrahospitalaria alcanza el 44% en la región, mostrando claro predominio en las áreas de menor población (Navalmoral de la Mata y Coria). El patrón de multirresistencia más frecuente es tobramicina-levofloxacino-eritromicina (44%), seguido de tobramicina-eritromicina-clindamicina (20%). No se obtienen cepas resistentes a linezolid, daptomicina o tigeciclina, sin embargo el 42% presentan sensibilidad disminuida a vancomicina. El análisis por PFGE revela la existencia de 27 genotipos, con 3 genotipos mayoritarios: E8a (25%), E7b (17%) y E7a (12%). El estudio estadístico post-hoc, no revela diferencias significativas en la distribución de genotipos entre las diferentes áreas, pero si algunas tendencias que deben tenerse en consideración (AU)

The correct surveillance and control of infection caused by methicillin-resistant Staphylococcus aureus (MRSA) needs of update knowledge of its specific properties in each place. Our study aims to describe the current characteristics of infection due to MRSA in Extremadura. During 2010, 309 MRSA were collected from clinical samples in our region. A susceptibility test that included 17 antibiotics tested by AST -588 card Vitek 2 ® and E -test method was performed on all isolates. A sample of 100 strains, selected by stratified random sampling, were genotyped by pulsed field electrophoresis (PFGE). The prevalence of MRSA in Extremadura was 20.2%. Don Benito-Villanueva area showed the most prevalence and a higher incidence. Merida reported the most favourable situation, with a relatively low ratios of prevalence and incidence. The community acquired reached 44 % in the region, showing predominantly in less populated areas (Navalmoral and Coria). The most common multiresistant pattern was tobramycin-levofloxacin-erythromycin (44%), followed tobramycin-erythromycin-clindamycin (20%). No linezolid, daptomycin and tigecycline resistant strains were observed, but 42 % of the MRSA strains showed decreased susceptibility vancomycin (DSV). PFGE analysis reported 27 genotypes, with 3 major genotypes: E8a (25%), E7b (17%) and E7a (12%). The post-hoc statistical analysis did not reveal significant differences in the distribution of genotypes between different areas. However it revealed some trends that should be considered (AU)