Target-based drug design strategies to overcome resistance to antiviral agents: opportunities and challenges.

Viral infections have a major impact in human health. Ongoing viral transmission and escalating selective pressure have the potential to favor the emergence of vaccine- and antiviral drug-resistant viruses. Target-based approaches for the design of antiviral drugs can play a pivotal role in combating drug-resistant challenges. Drug design computational tools facilitate the discovery of novel drugs. This review provides a comprehensive overview of current drug design strategies employed in the field of antiviral drug resistance, illustrated through the description of a series of successful applications. These strategies include technologies that enhance compound-target affinity while minimizing interactions with mutated binding pockets. Furthermore, emerging approaches such as virtual screening, targeted protein/RNA degradation, and resistance analysis during drug design have been harnessed to curtail the emergence of drug resistance. Additionally, host targeting antiviral drugs offer a promising avenue for circumventing viral mutation. The widespread adoption of these refined drug design strategies will effectively address the prevailing challenge posed by antiviral drug resistance.

Epiretinal neovascular membrane in Macular Telangiectasia type 2: Multimodal imaging diagnosis.

PURPOSE: To characterize an epiretinal neovascular membrane (ERNM) through multimodal imaging in the context of a patient with Macular Telangiectasia type 2 (MacTel) and ipsilateral concomitant ocular ischemic syndrome (OIS). METHODS: Case report, with ultra-wide field (UWF) retinography, fluorescein angiography (FA), swept source optical coherence tomography (ss-OCT), and OCT-angiography (OCTA). Written informed consent for patient information and images to be published was provided by the patient. Approval from the Research Ethics Committee of the Hospital was obtained for publication. CASE REPORT: Yearly follow up of a 51 year-old-female patient with advanced bilateral MacTel showed new punctate hemorrhages in all four quadrants of her right eye (OD). OCTA showed an ERNM in the superficial capillary plexus of the same eye and FA confirmed the ERNM and demonstrated peripheral ischemia. Carotid ultrasound was performed and complete right carotid artery occlusion was confirmed. These findings allowed the diagnosis of an ERNM associated with Mactel and OIS. CONCLUSIONS: Interestingly, this case shows an ERNM diagnosed by multimodal imaging in a patient with advanced MacTel and a concomitant OIS. Mactel is a neurodegenerative disease which in its neovascular stage has been associated with macular neovascular membranes, but also ERNM have recently been described by OCTA.

Emerging drug design strategies in anti-influenza drug discovery.

Influenza is an acute respiratory infection caused by influenza viruses (IFV), According to the World Health Organization (WHO), seasonal IFV epidemics result in approximately 3-5 million cases of severe illness, leading to about half a million deaths worldwide, along with severe economic losses and social burdens. Unfortunately, frequent mutations in IFV lead to a certain lag in vaccine development as well as resistance to existing antiviral drugs. Therefore, it is of great importance to develop anti-IFV drugs with high efficiency against wild-type and resistant strains, needed in the fight against current and future outbreaks caused by different IFV strains. In this review, we summarize general strategies used for the discovery and development of antiviral agents targeting multiple IFV strains (including those resistant to available drugs). Structure-based drug design, mechanism-based drug design, multivalent interaction-based drug design and drug repurposing are amongst the most relevant strategies that provide a framework for the development of antiviral drugs targeting IFV.

Correlation between Topographic Vessel Density and Retinal Thickness Changes in Patients with Diabetic Macular Edema Treated with Anti-VEGF Therapy: Is It a Suitable OCTA Biomarker?

The objective of this study was to determine the correlation between topographic vessel density (VD) and retinal thickness (RT) reductions induced by vascular endothelial growth factor inhibitors (anti-VEGF) in patients with diabetic macular edema (DME) using optical coherence tomography angiography (OCTA). This was a prospective, interventional case series. VD and RT measurements were separately taken in four parafoveal subfields at baseline and after six months of treatment. This correlation was statistically assessed using Spearman's rho correlation coefficient after adjustment for multiple comparisons. The study included a total of 48 eyes in the final analysis. Mean VD decreased from baseline to month 6 (from 45.2 (±3.5) to 44.6% (±3.2) in the superficial capillary plexus and from 50 (±3.3) to 49% (±3.9) in the deep capillary plexus). Statistically significant reductions in RT were observed in all ETDRS sectors (p < 0.0001). No significant association was found between RT and VD, even when analyzing responders and non-responders separately. After six months of anti-VEGF treatment, no significant correlation was observed between the topographic VD and RT values. These findings suggest that reductions in VD values may not solely result from a reduction in microaneurysms, also being affected by the repositioning of displaced vessels due to edema and a reduction in their caliber. Therefore, VD changes may not be a suitable indirect OCTA biomarker of microaneurysm turnover and treatment response.

Choriocapillaris and choroidal thickness in all Leber hereditary optic neuropathy stages using swept source technology.

PURPOSE: The role of the choroid in Leber hereditary optic neuropathy (LHON) remains unclear. The literature is scarce, with conflicting results and lacks axial length measurements. Therefore, we aimed to analyse the choriocapillaris (CC) vessel density (VD) and choroidal thickness (ChT) in all stages of LHON using swept source (SS) technology and considering the possible influence of axial length on choroidal parameters. METHODS: This was a prospective cross-sectional observational study. A total of 119 eyes of 60 patients with molecularly confirmed LHON across all stages and 120 eyes of 60 control participants were included. We obtained the CC VD using optical coherence tomography angiography maps centred on the fovea. ChT was measured from the Bruch's membrane to the choroid-sclera interface in the macular and peripapillary regions. RESULTS: The CC VD was not significantly affected in any sector or average, except for a slight change in the superior region of chronic eyes (52.08 ± 1.62% vs. 53.50 ± 2.29%, p = 0.002). ChT demonstrated a trend towards decreased values in asymptomatic eyes and increased values in the symptomatic stages that failed to reach statistical significance in sectors corresponding to the papillomacular bundle except for the macular nasal inner sector of chronic eyes (281.10 ± 67.12 µm vs. 252.08 ± 70.55 µm, p = 0.045). No significant correlations were observed between visual acuity and CC VD or ChT. CONCLUSION: The CC VD remained stable across the LHON stages. Choroidal vasculature does not appear to play a role in LHON pathophysiology. Further research is needed on ChT as a potential biomarker of LHON.

Obesity and the obesity paradox in patients with severe COVID-19 / Obesidad y paradoja de la obesidad en pacientes con COVID-19 severo: Resultados de dos cohortes prospectivas

Objective: To test the presence of the obesity paradox in two cohorts of patients hospitalized for COVID-19. Design: Two multicenter prospective cohorts. Setting: Three fourth level institutions. Patients: Adults hospitalized in the general ward for confirmed COVID-19 in the three institutions and those admitted to one of the 9 critical care units of one of the institutions. Interventions: None. Main variables of interest: Categorized weight and its relationship with admission to the ICU in hospitalized patients and death in the ICU. Result: Of 402 hospitalized patients, 30.1% were obese. Of these, 36.1% were admitted to the ICU vs. 27.1% of non-obese patients. Of the 302 ICU patients, 46.4% were obese. Of these, mortality was 45.0% vs. 52.5% for non-obese. The requirement to transfer hospitalized patients to the ICU admission get a HR of 1.47 (95%CI 0.87–2.51, p = 0.154) in the multivariate analysis. In intensive care patients, an HR of 0.99 (95%CI: 0.92–1.07, p = 0.806) was obtained to the association of obesity with mortality. Conclusions: The present study does not demonstrate an association between obesity and risk of inpatient transfer to intensive care or death of intensive care patients due to COVID-19 therefore, the presence of an obesity paradox is not confirmed. (AU)

Objetivo: Comprobar la presencia la paradoja de la obesidad en dos cohortes de pacientes hospitalizados por COVID-19. Diseño: Dos cohortes prospectivas multicéntricas. Ámbito: Tres instituciones de cuarto nivel. Pacientes: Adultos hospitalizados en pabellón general por COVID-19 confirmado en las tres instituciones y aquellos internados en alguna de las 9 unidades de cuidado crítico de una de las instituciones. Intervenciones: Ninguna. Variables de interés principales: El peso categorizado y su relación con el ingreso a UCI en hospitalizados y de muerte en UCI. Resultado: Entre 402 hospitalizados 30.1% fueron obesos, de los que 36.1% ingresaron a UCI vs. 27.1% en los no obesos. De los 302 pacientes en UCI, el 46.4% fueron obesos, entre ellos la mortalidad fue de 45.0% vs. 52.5% en los no obesos. En hospitalizados el análisis multivariado obtuvo HR de 1.47 (IC95% 0.87–2.51, p = 0.154) para traslado a UCI. En UCI se obtuvo un OR de 0.99 (IC95%: 0.92–1.07, p = 0.806) para la muerte. Conclusiones: El presente estudio no demuestran una asociación entre la obesidad y el riesgo de traslados a cuidados intensivos en pacientes hospitalizados ni con la muerte en pacientes en cuidados intensivos por COVID-19 por lo que no se confirma la presencia de una paradoja de la obesidad. (AU)

Charge Engineering of the Nucleic Acid Binding Cleft of a Thermostable HIV-1 Reverse Transcriptase Reveals Key Interactions and a Novel Mechanism of RNase H Inactivation.

Coupled with PCR, reverse transcriptases (RTs) have been widely used for RNA detection and gene expression analysis. Increased thermostability and nucleic acid binding affinity are desirable RT properties to improve yields and sensitivity of these applications. The effects of amino acid substitutions in the RT RNase H domain were tested in an engineered HIV-1 group O RT, containing mutations K358R/A359G/S360A and devoid of RNase H activity due to the presence of E478Q (O3MQ RT). Twenty mutant RTs with Lys or Arg at positions interacting with the template-primer (i.e., at positions 473-477, 499-502 and 505) were obtained and characterized. Most of them produced significant amounts of cDNA at 37, 50 and 65 °C, as determined in RT-PCR reactions. However, a big loss of activity was observed with mutants A477K/R, S499K/R, V502K/R and Y505K/R, particularly at 65 °C. Binding affinity experiments confirmed that residues 477, 502 and 505 were less tolerant to mutations. Amino acid substitutions Q500K and Q500R produced a slight increase of cDNA synthesis efficiency at 50 and 65 °C, without altering the KD for model DNA/DNA and RNA/DNA heteroduplexes. Interestingly, molecular dynamics simulations predicted that those mutations inactivate the RNase H activity by altering the geometry of the catalytic site. Proof of this unexpected effect was obtained after introducing Q500K or Q500R in the wild-type HIV-1BH10 RT and mutant K358R/A359G/S360A RT. Our results reveal a novel mechanism of RNase H inactivation that preserves RT DNA binding and polymerization efficiency without substituting RNase H active site residues.

Targeting hepatitis B virus cccDNA levels: Recent progress in seeking small molecule drug candidates.

Hepatitis B virus (HBV) infection is a major global health problem that puts people at high risk of death from cirrhosis and liver cancer. The presence of covalently closed circular DNA (cccDNA) in infected cells is considered to be the main obstacle to curing chronic hepatitis B. At present, the cccDNA cannot be completely eliminated by standard treatments. There is an urgent need to develop drugs or therapies that can reduce HBV cccDNA levels in infected cells. We summarize the discovery and optimization of small molecules that target cccDNA synthesis and degradation. These compounds are cccDNA synthesis inhibitors, cccDNA reducers, core protein allosteric modulators, ribonuclease H inhibitors, cccDNA transcriptional modulators, HBx inhibitors and other small molecules that reduce cccDNA levels.

Obesity and the obesity paradox in patients with severe COVID-19.

OBJECTIVE: To test the presence of the obesity paradox in two cohorts of patients hospitalized for COVID-19. DESIGN: Two multicenter prospective cohorts. SETTING: Three fourth level institutions. PATIENTS: Adults hospitalized in the general ward for confirmed COVID-19 in the three institutions and those admitted to one of the 9 critical care units of one of the institutions. INTERVENTIONS: None. MAIN VARIABLES OF INTEREST: Categorized weight and its relationship with admission to the ICU in hospitalized patients and death in the ICU. RESULT: Of 402 hospitalized patients, 30.1% were obese. Of these, 36.1% were admitted to the ICU vs. 27.1% of non-obese patients. Of the 302 ICU patients, 46.4% were obese. Of these, mortality was 45.0% vs. 52.5% for non-obese. The requirement to transfer hospitalized patients to the ICU admission get a HR of 1.47 (95%CI 0.87-2.51, p = 0.154) in the multivariate analysis. In intensive care patients, an HR of 0.99 (95%CI: 0.92-1.07, p = 0.806) was obtained to the association of obesity with mortality. CONCLUSIONS: The present study does not demonstrate an association between obesity and risk of inpatient transfer to intensive care or death of intensive care patients due to COVID-19 therefore, the presence of an obesity paradox is not confirmed.

Estimation of reinforced urn processes under left-truncation and right-censoring.

We propose a non-parametric estimator for bivariate left-truncated and right-censored observations that combines the expectation-maximization algorithm and the reinforced urn process. The resulting expectation-reinforcement algorithm allows for the inclusion of experts' knowledge in the form of a prior distribution, thus belonging to the class of Bayesian models. This can be relevant in applications where the data is incomplete, due to biases in the sampling process, as in the case of left-truncation and right-censoring. With this new approach, the distribution of the truncation variables is also recovered, granting further insight into those biases, and playing an important role in applications like prevalent cohort studies. The estimators are tested numerically using artificial and empirical datasets, and compared with other methodologies such as copula models and the Kaplan-Meier estimator.

The First Latin American Consensus on Superficial and Perforating Venous Mapping.

With the aim of obtaining a map which is useful as a diagnostic tool and therapeutical orientation, complementing the written report of duplex ultrasound venous study, Latin-American Scientific Societies of Phlebology, Vascular Surgery and Vascular Imaging were invited to participate, through their regional representatives, to the First Consensus of Superficial and Perforating Venous Mapping. A consensus process using a modified Delphi method was carried out. An International Working Group was formed, which developed a Prototype of the Venous Mapping that worked as a starting point for consensus, and was presented in a first virtual meeting of 54 experts (societies' representatives) when the methodology was explained. For the consensus process, two rounds of self-administrated questionnaires with feedback were used. In the first questionnaire a 100% consensus was obtained in the 15 statements (an agreement range of 85.2% to 100%) In the analysis of qualitative data, three categories according to the actions to implement were identified - actions which involved no action, minor changes and major changes. This analysis was used to build the second questionnaire, which reached a consensus in its six statements (agreement range of 87.1% to 98.1%). A final consensus on every field proposed was established with the approval of all the experts consulted and it was presented at a third online meeting. The document of the superficial and perforating venous mapping reached by consensus is presented hereafter.

Predicting kidney outcomes among Latin American patients with lupus nephritis: The prognostic value of interstitial fibrosis and tubular atrophy and tubulointerstitial inflammation.

OBJECTIVE: To assess the effect of tubulointerstitial inflammation (TII) and interstitial fibrosis and tubular atrophy (IFTA) on kidney survival in lupus nephritis (LN). METHODS: Two hundred eighty five patients with biopsy-proven LN were retrospectively studied. Kidney survival was defined as the time from initial biopsy to end-stage kidney disease (ESKD), dialysis, or transplant. Kidney survival analysis was performed by the Kaplan-Meier method and the statistical difference between survival curves compared by the log-rank test. Cumulative incidence functions with competing risk of death for kidney survival were also graphed. Multivariable Cox proportional hazards regression and competing-risk analyses were performed to identify independent predictors of ESKD. RESULTS: Fifty-seven patients (20%) progressed to ESKD during a median time of 4.2 (2.0-55.2) months after biopsy. TII was present in 206 (72.3%) biopsies, while IFTA in 99 (34.7%) biopsies. Patients with moderate-to-severe IFTA had worse kidney survival than those with none or mild IFTA in both the Kaplan-Meier (p = 0.018) and the competing-risk analyses (p = 0.017). Patients with class IV ± V LN had worse kidney survival than those with non-class IV LN by the Kaplan-Meier method (p = 0.050), but not in the competing-risk analysis (p = 0.154). Worse kidney survival was also found among those with fibrous crescents than those without, in both the Kaplan-Meier (p = 0.010) and the competing-risk (p = 0.011) analyses. By multivariable Cox regression analysis, older age (HR 1.04, 95% CI 1.01-1.07) and class IV ± V LN (HR 5.06, 95% CI 1.82-14.09) were associated with higher risk of ESKD after adjusting for sex, ethnicity, TII, and IFTA. By competing-risk analyses, class IV ± V LN (SHR 3.32, 95% CI 1.25-8.83) and no response to immunosuppressive therapy (SHR 4.55, 95% CI 1.54-13.41) were associated with a higher risk of ESKD, while eGFR >90 mL/min/1.73 m2 (SHR 0.98 for each ml/min/1.73 m2, 95% 0.97-0.99) with a lower risk. CONCLUSIONS: Patients with moderate-to-severe IFTA had worse kidney survival than those with none or mild IFTA. Worse kidney survival was also found among those with class IV LN and fibrous crescents versus those without IV LN and fibrous crescents, respectively.

Hydroxychloroquine safety in Covid-19 vs non-Covid-19 patients: analysis of differences and potential interactions.

BACKGROUND: The use of hydroxychloroquine (HCQ) in the first COVID-19 epidemic wave raised safety concerns. RESEARCH DESIGN AND METHODS: Adverse reactions (ADR) suspected to be induced by HCQ and submitted to the Spanish Pharmacovigilance Database were studied. A disproportionality analysis was performed to determine adverse effects reported in non-Covid and Covid patients. To explore potential drug-drug interactions, Omega (Ω) statistics was calculated. RESULTS: More severe cases were reported when used in COVID-19. Main differences in frequency were observed in hepatobiliary, skin, gastrointestinal, eye, nervous system and heart ADRs. During the COVID-19 pandemic, high disproportionality in reports was found for Torsade de Pointes/QT prolongation with a ROR (-ROR) of 132.8 (76.7); severe hepatotoxicity, 18.7 (14.7); dyslipidaemias, 12.1 (6.1); shock, 9.5 (6.9) and ischemic colitis, 8.9 (2.6). Myopathies, hemolytic disorders and suicidal behavior increased their disproportionality during the pandemic. Disproportionality was observed for neoplasms, hematopoietic cytopaenias and interstitial lung disease in the pre-COVID-19 period. Potential interactions were showed between HCQ and azithromycin, ceftriaxone, lopinavir and tocilizumab. CONCLUSIONS: The use of HCQ during the Covid-19 pandemic changed its ADRs reporting profile. Of particular concern during the pandemic were arrhythmias, hepatotoxicity, severe skin reactions and suicide, but not ocular disorders. Some signals identified would require more detailed analyses.

Local Resection in Choroidal Melanoma: A Review.

Surgical resection is widely used to treat small tumours located in the iris and the ciliary body, due to the accessibility of these sites. By contrast, surgical removal of choroidal tumours is substantially more challenging, which is why this procedure is performed only at specialised centres. In the present article, we review the literature on surgical resection of choroidal tumours, which can be performed as endoresection (ab interno) or transscleral resection (ab externo). An important aim of this review is to describe and compare the two approaches in terms of visual outcomes, survival rates, and complications. Both approaches are indicated for the removal of large tumours (thickness > 8 mm) with small base diameters. Surgical resection of the tumour allows clinicians to obtain valuable histopathologic and cytogenetic data from the specimen and eliminates the risks associated with radiotherapy. However, both of these surgical approaches are technically challenging procedures involving the risk of severe early and late postoperative complications.

Síndrome nefrótico como manifestación de microangiopatía trombótica secundaria al uso crónico de sunitinib / Nephrotic syndrome as a manifestation of thrombotic microangiopathy due to long-term use of sunitinib

El síndrome nefrótico en los pacientes con cáncer se puede asociar a su enfermedad de base o al tratamiento quimioterapéutico. El cáncer de órganos sólidos puede producir una glomerulonefritis membranosa que se manifiesta con síndrome nefrótico; otras presentaciones histológicas menos frecuentes son la glomeruloesclerosis focal y segmentaria y la enfermedad de cambios mínimos. Adicionalmente, los tratamientos quimioterapéuticos pueden causar toxicidad renal por afección de los pequeños vasos sanguíneos, los glomérulos, los túbulos y el intersticio. Los inhibidores de la tirosina quinasa como el sunitinib pueden causar daño endotelial y podocitario, produciendo una microangiopatía trombótica limitada a los riñones, que se manifiesta con proteinuria e hipertensión. Se presenta el caso de un hombre anciano con tumor del estroma gastrointestinal (GIST, por sus siglas en inglés) que fue tratado con sunitinib y como complicación presentó una microangiopatía trombótica manifestada con síndrome nefrótico e hipertensión de difícil control, que se controló al suspender este medicamento pero con desenlace fatal por su neoplasia maligna. (AU)

Nephrotic syndrome in patients with cancer may be related to the primary malignancy or chemotherapeutic therapy. Solid organ cancers may cause membranous glomerulonephritis manifesting with nephrotic syndrome; other less common histologic presentations include focal and segmental glomerulosclerosis and minimal change disease. In addition, chemotherapy agents can cause renal toxicity by affecting the small blood vessels, glomeruli, tubules, and interstitium. Tyrosine kinase inhibitors such as sunitinib may cause endothelial and podocyte damage leading to renal limited thrombotic microangiopathy, manifested by proteinuria and hypertension. We report a case of an elderly man with gastrointestinal stromal tumor (GIST) on treatment with sunitinib who had as a complication of a thrombotic microangiopathy manifested with nephrotic syndrome and difficult-to-control hypertension, which was controlled by stopping this drug but with a fatal outcome due to its malignant neoplasm. (AU)

Current medicinal chemistry strategies in the discovery of novel HIV-1 ribonuclease H inhibitors.

During HIV-1 genome replication, the viral reverse transcriptase-associated ribonuclease H (RT-associated RNase H) activity hydrolyzes the RNA strand of RNA/DNA heteroduplex intermediates. As of today, HIV-1 RNase H inhibitors (RHIs) remain at an investigational level, although none of them reached clinical trials. Therefore, RNase H remains as an attractive target for drug design and development. In this paper, we review the current status of medicinal chemistry strategies aimed at the discovery of novel RHIs, while discussing problems encountered in their characterization and further development, thereby providing an update on recent progress in the field.

Ziehl-Neelsen stain in the pathology laboaratory: Performance and diagnostic aid for mycobacteria in bronchoalveolar lavage / Coloración de Ziehl-Neelsen en el laboratorio de patología: rendimiento y contribución al diagnóstico de micobacterias en el lavado broncoalveolar.

Introduction: With more than 100 years of use, the Ziehl-Neelsen stain is still currently used worldwide. Objective: To compare the performance of diagnostic tests used to determine mycobacteria in the clinic and pathology laboratory in bronchoalveolar lavage samples. Materials and methods: We retrospectively reviewed 737 bronchoalveolar lavage samples from 2019 to 2020 in the San Vicente Fundación hospital (Medellín, Colombia) comparing the performance of three tests done in parallel: mycobacteria and resistance PCR, culture, and Ziehl-Neelsen stain. Results: In total, 93/737 patients were classified as sick due to a positive result in any of the three tests. The culture, PCR, and Ziehl-Neelsen stain had a sensibility of 0.80, 0.76 y 0.51, respectively. However, only 5/75 (6.5%) of the positive cultures had results within the first four weeks and the rest in eight weeks. The PCR test combined with the Ziehl-Neelsen stain improved the sensibility of the PCR test alone from 0.76 a 0.88, a change that was statistically significant (p = 0.022). Conclusion: At least in bronchoalveolar lavage samples, culture is still the test with better sensibility. The use in parallel of the PCR test and the Ziehl-Neelsen stain improved in a statistically significant manner the performance of the PCR test alone, regardless of the higher turnaround time of the Ziehl-Neelsen stain.

Introducción. La coloración de Ziehl-Neelsen, con más de 100 años de uso, continúa vigente mundialmente. Objetivo. Comparar el rendimiento de las pruebas diagnósticas utilizadas para la determinación de micobacterias en el laboratorio clínico de patología en muestras de lavado broncoalveolar. Materiales y métodos. Se revisaron retrospectivamente 737 muestras de lavado broncoalveolar procesadas en el 2019 y el 2020 en el Hospital San Vicente Fundación (Medellín, Colombia) y se compararon las características de tres pruebas diagnósticas realizadas en paralelo: la reacción en cadena de la polimerasa (PCR) para micobacterias con detección de resistencia, el cultivo, y la coloración de Ziehl-Neelsen. Resultados. Se catalogaron como enfermos a 93 de los 737 pacientes a partir de los resultados positivos en alguna de las tres pruebas. El cultivo tuvo una sensibilidad de 0,80, la PCR una de 0,76 y la coloración de Ziehl-Neelsen una de 0,51. Sin embargo, solo 5 de 75 (6,5 %) cultivos fueron positivos a las cuatro semanas y el resto lo fue a las ocho semanas. La PCR combinada con la coloración de Ziehl-Neelsen mejoró la sensibilidad de la PCR por sí sola, de 0,76 a 0,88, diferencia que fue estadísticamente significativa (p=0,022). Conclusión. En las muestras de lavado broncoalveolar, el cultivo sigue siendo la prueba con mejor sensibilidad. El uso conjunto de la prueba de PCR y la coloración de Ziehl-Neelsen mejora significativamente la sensibilidad de la primera, lo que compensa la demora relativa en la entrega de los resultados debida al tiempo requerido para la tinción de Ziehl-Neelsen.

Coloración de Ziehl-Neelsen en el laboratorio de patología: rendimiento y contribución al diagnóstico de micobacterias en el lavado broncoalveolar / Ziehl-Neelsen stain in the pathology laboaratory: Performance and diagnostic aid for mycobacteria in bronchoalveolar lavage

Introducción. La coloración de Ziehl-Neelsen, con más de 100 años de uso, continúa vigente mundialmente. Objetivo. Comparar el rendimiento de las pruebas diagnósticas utilizadas para la determinación de micobacterias en el laboratorio clínico de patología en muestras de lavado broncoalveolar. Materiales y métodos. Se revisaron retrospectivamente 737 muestras de lavado broncoalveolar procesadas en el 2019 y el 2020 en el Hospital San Vicente Fundación (Medellín, Colombia) y se compararon las características de tres pruebas diagnósticas realizadas en paralelo: la reacción en cadena de la polimerasa (PCR) para micobacterias con detección de resistencia, el cultivo, y la coloración de Ziehl-Neelsen. Resultados. Se catalogaron como enfermos a 93 de los 737 pacientes a partir de los resultados positivos en alguna de las tres pruebas. El cultivo tuvo una sensibilidad de 0,80, la PCR una de 0,76 y la coloración de Ziehl-Neelsen una de 0,51. Sin embargo, solo 5 de 75 (6,5 %) cultivos fueron positivos a las cuatro semanas y el resto lo fue a las ocho semanas. La PCR combinada con la coloración de Ziehl-Neelsen mejoró la sensibilidad de la PCR por sí sola, de 0,76 a 0,88, diferencia que fue estadísticamente signifcativa (p=0,022). Conclusión. En las muestras de lavado broncoalveolar, el cultivo sigue siendo la prueba con mejor sensibilidad. El uso conjunto de la prueba de PCR y la coloración de ZiehlNeelsen mejora signifcativamente la sensibilidad de la primera, lo que compensa la demora relativa en la entrega de los resultados debida al tiempo requerido para la tinción de Ziehl-Neelsen.

Introduction: With more than 100 years of use, the Ziehl-Neelsen stain is still currently used worldwide. Objective: To compare the performance of diagnostic tests used to determine mycobacteria in the clinic and pathology laboratory in bronchoalveolar lavage samples. Materials and methods: We retrospectively reviewed 737 bronchoalveolar lavage samples from 2019 to 2020 in the San Vicente Fundación hospital (Medellín, Colombia) comparing the performance of three tests done in parallel: mycobacteria and resistance PCR, culture, and Ziehl-Neelsen stain. Results: In total, 93/737 patients were classifed as sick due to a positive result in any of the three tests. The culture, PCR, and Ziehl-Neelsen stain had a sensibility of 0.80, 0.76 y 0.51, respectively. However, only 5/75 (6.5%) of the positive cultures had results within the frst four weeks and the rest in eight weeks. The PCR test combined with the Ziehl-Neelsen stain improved the sensibility of the PCR test alone from 0.76 a 0.88, a change that was statistically signifcant (p = 0.022). Conclusion: At least in bronchoalveolar lavage samples, culture is still the test with better sensibility. The use in parallel of the PCR test and the Ziehl-Neelsen stain improved in a statistically signifcant manner the performance of the PCR test alone, regardless of the higher turnaround time of the Ziehl-Neelsen stain.