ABSTRACT Introduction: Pneumocystis jirovecii pneumonia is one of the diseases causing the greatest negative impact on AIDS patients. The impossibility of culturing its causative agent, its unspecific clinical presentation and the high cost of molecular diagnostic methods, make it necessary to find other diagnostic alternatives. The lactate dehydrogenase test is an option to be considered. Objective: Demonstrate the usefulness of the lactate dehydrogenase test to diagnose Pneumocystis jirovecii in Cuban patients deceased with AIDS. Methods: A case-control study was conducted (25 cases [Pneumocystis jirovecii] and 30 controls [distributed into three groups: tuberculosis, lymphoma and bacterial pneumonia, respectively]) of Cuban deceased patients undergoing post-mortem examination from January 1996 to December 2016. Five cutoff ranges were used to find the optimal value of the test. Results: Highly significant differences were found between the patients analyzed (cases and controls) and between the remaining individuals making up the controls with respect to the one with lymphoma. The optimal cutoff range for the lactate dehydrogenase test was 550-<800 U/I, with 80% sensitivity and 63% specificity. The odds ratio (OR) showed that probabilities are 6.91 times greater that Pneumocystis jirovecii pneumonia patients have higher LDH figures than control patients. Conclusions: Scientific evidence is contributed of the role of the lactate dehydrogenase test as a complementary tool in the diagnosis of Pneumocystis jirovecii.

RESUMEN Introducción: La neumonía por Pneumocystis jirovecii es una de las enfermedades de mayor impacto negativo en los pacientes con sida. La imposibilidad de cultivar el agente que la provoca, así como su cuadro clínico inespecífico y el alto costo de los métodos diagnósticos moleculares, señalan la necesidad de otras alternativas para su diagnóstico. La prueba de la lactato deshidrogenasa representa una opción a considerar. Objetivo: Demostrar la utilidad de la prueba de la lactato deshidrogenasa como diagnóstico de la Pneumocystis jirovecii en fallecidos cubanos por sida. Métodos: Se realizó un estudio de casos y controles (25 casos [Pneumocystis jirovecii] y 30 controles [compuestos por tres grupos: tuberculosis, linfoma y neumonía bacteriana, respectivamente]) en fallecidos cubanos a los que se realizó la autopsia desde enero de 1996 a diciembre de 2016. Se utilizaron cinco rangos de corte para buscar el valor óptimo de la prueba. Resultados: En el presente estudio existen diferencias altamente significativas entre los pacientes analizados (casos y controles) y entre los restantes individuos que componen los controles con respecto al del linfoma. El rango de corte óptimo para la prueba de la lactato deshidrogenasa fue (550-<800 U/I) con sensibilidad de 80 % y especificidad de 63 %. La razón de disparidad (OR) demostró que existe 6,91 veces más probabilidades que los pacientes por Pneumocystis jirovecii tengan las cifras de LDH mayor que los pacientes controles. Conclusiones: Este trabajo aporta evidencias científicas del rol de la prueba de la lactato deshidrogenasa como herramienta complementaria para el diagnóstico de la Pneumocystis jirovecii.

ABSTRACT Latent tuberculosis infection (LTBI) is a condition that has no clinical signs and symptoms. LTBI patients are characterized by persistent immune responses to Mycobacterium tuberculosis, and approximately 5-10% of these infected individuals will develop active TB at some point in their lives. The antigen transporter associated with antigen processing (TAP1) is a protein involved in the transport of the antigen from the cytoplasm to the endoplasmic reticulum by means of the association with MHC class I molecules. It plays a fundamental role in the immune response, promoting the clearance of intracellular pathogens. Our pilot study aimed to determine the association between TAP1 gene 1177A>G (rs1057141) and 2090A>G (rs1135216) genetic polymorphisms with susceptibility to LTBI. In this case-control study, 153 individuals from shelters were analyzed (46 were LTBI-positive and 92 were controls). Genotyping of the rs11352216 (2090A>G) and rs1057141 (1177A>G) gene IDs was performed using the Applied Biosystems Step One Thermal Cycler Real-Time PCR allelic discrimination technology. The haplotypic analyses were performed with the Arlequin 3.5 program. Social assistance centers and shelters that serve vulnerable populations represent high-risk sites due to overcrowding and the impaired nutritional status of their residents. The G allele (OR=1.99, CI=1.109-3.587, p=0.021) and the GG genotype of rs11352216 (A>G) were associated with susceptibility to LTBI, according to the codominant genetic model (OR=8.32, CI=1.722-61.98, p=0.007). The rs1057141 (A>G) polymorphism was not associated with LTBI risk. The results suggest that carriers of the G allele of rs1135216 (A>G) are susceptible to LTBI.

BACKGROUND Infective endocarditis is a disease characterised by heart valve lesions, which exhibit extracellular matrix proteins that act as a physical barrier to prevent the passage of antimicrobial agents. The genus Candida has acquired clinical importance given that it is increasingly being isolated from cases of nosocomial infections. OBJECTIVE To evaluate the activity of caspofungin compared to that of liposomal amphotericin B against Candida albicans in experimental infective endocarditis. METHODS Wistar rats underwent surgical intervention and infection with strains of C. albicans to develop infective endocarditis. Three groups were formed: the first group was treated with caspofungin, the second with liposomal amphotericin B, and the third received a placebo. In vitro sensitivity was first determined to further evaluate the effect of these treatments on a rat experimental model of endocarditis by semiquantitative culture of fibrinous vegetations and histological analysis. FINDINGS Our semiquantitative culture of growing vegetation showed massive C. albicans colonisation in rats without treatment, whereas rats treated with caspofungin showed significantly reduced colonisation, which was similar to the results obtained with liposomal amphotericin B. CONCLUSIONS The antifungal activity of caspofungin is similar to that of liposomal amphotericin B in an experimental model of infective endocarditis caused by C. albicans.

Candida albicans is the most common fungal pathogen known to cause endovascular infections, such as vascular catheter sepsis, infections of vascular prostheses and infective endocarditis. A C. albicans isolate was used to determine the apoptotic potential of the fungus in a rat endocarditis model. This study confirms the ability of C. albicans to induce apoptosis in myocardial tissue.