Browsing by Author "Pérez, Héctor"

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    Candidiasis esofágica: análisis clínico y micológico
    (2005) Olmos, Martín A; Araya, Valentina; Concetti, Hugo; Ramallo, Jennifer; Piskorz, Eduardo; Pérez, Héctor; Cahn, Pedro; Kaufman, Sara; Guelfand, Liliana
    La candidiasis esofágica es una infección epitelial que requiere un defecto adicional inmunitario. Candida albicans es la especie más frecuente, aunque pueden encontrarse otras. Un problema emergente es la resistencia al fluconazol, droga de elección para tratarla. Los objetivos fueron: determinar la frecuencia de candidiasis esofágica en pacientes sometidos a endoscopía, analizar los factores predisponentes, identificar las especies causantes, y estudiar la sensibilidad in vitro al fluconazol. Durante 12 meses se realizaron 1.321 endoscopías donde se detectaron 34 pacientes con candidiasis esofágica. Se hicieron 1.230 endoscopías en pacientes HIV negativos y 91 en HIV positivos. Se diagnosticó candidiasis esofágica en 11 (0.9%) y 23 (25.3%), respectivamente. En HIV negativos, fueron causas predisponentes: antibioticoterapia prolongada, prótesis dentarias sin higiene, uso prolongado de inhibidores de la bomba de protones, secreción ácida, corticoides inhalatorios, malignidad y vasculitis bajo corticoterapia. La histopatología fue positiva en 48.6%. El cultivo se desarrolló en el 91.2%. C. albicans fue la especie más frecuente (93.5%) y en 5 pacientes (16.1%) se la encontró asociada a C. glabrata (3) C. tropicalis (1) y C. parapsilosis (1). En un caso solo se cultivó C. glabrata y en otro C. tropicalis. De las 31 cepas, 25 fueron sensibles al fluconazol, 4 dosis dependientes (1 C. albicans, 3 C. glabrata), y 2 resistentes (1 C. albicans, 1 C. glabrata). En nuestro hospital, la frecuencia de candidiasis esofágica fue baja, excepto en HIV positivos. El principal agente etiológico fue C. albicans, aunque también se cultivaron otras especies. C. albicans y C. glabrata mostraron dosis dependencia y resistencia al fluconazol.
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    Factores contextuales, sociales e individuales como barreras y facilitadores para el acceso a la salud de mujeres trans: desde la perspectiva de la comunidad
    (2018-12) Zalazar, Virginia; Aristegui, Ines; Cardozo, Nadir; Sued, Omar; Rodríguez, Allan E.; Frola, Claudia; Pérez, Héctor
    Background: Transgender women (TGW) are vulnerable to several health problems, including HIV and other STDs, which significantly reduces their life expectancy. Therefore, there is an urgent need to understand factors affecting access to healthcare. Methods: A qualitative study was conducted among TGW living in rooming houses (TRH) in Buenos Aires. The objective of the study was to explore contextual, social and individual barriers and facilitators to access healthcare, particularly HIV services, and the acceptability of interventions. Two focus groups and five interviews were conducted in three TRH. Results: Contextual barriers described were the limited number of appointments and long waiting hours. Social obstacles included health workers’ stigma and discrimination and blaming of TGW for their health burdens, as well as HIV stigma within TGW groups. Most important facilitator were inclusive services. Individual barriers were self-exclusion and anticipated stigma, resulting in high rates of self-medication and industrial silicone injection. Peers play an important role by accompanying others TGW to healthcare. While reporting similar problems, TGW recommended different interventions according to their THR profile. Conclusions: As the stigma and discrimination is the most important barrier, it is imperative to ensure awareness of transgender issues for all personnel of healthcare services. It is necessary to implement a wide range of strategies in health facilities, and evaluate the community acceptance of domiciliary interventions, in order to respond to the different demands of this population.
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    Low Rate of Emergence of Nevirapine and Lamivudine Resistance after Post-Partum Interruption of a Triple-Drug Regimen
    (2008-01-01) Pérez, Héctor; Vignoles, Moira; Laufer, Natalia; Gómez, Alejandro; Coll, Patricia; Lattner, Jorge; Rolón, María José; Salomon, Horacio ; Cahn, Pedro
    Introduction Emergence of nevirapine (NVP) resistance may be a consequence of its use in monotherapy to prevent HIV mother-to-child transmission (MTCT). The aim of this study was to evaluate the emergence of strains resistant to NVP and lamivudine (3TC) after discontinuation of anti-retroviral therapy (ART) with 3TC/zidovudine (ZDV)/NVP. Methods Twenty pregnant women (ART-naive or pre-exposed only to ZDV), to whom 3TC/ZDV/NVP was prescribed as MTCT prophylaxis, were studied. They received ART for a median of 4 months with median viral load (VL) at labour <50 copies/ml. Samples were collected between 1 and 15 months (median: 3 months) after ART interruption. Sequence-selective real-time PCR (SPCR), which quantifies minority viral populations containing K103N, Y181C and M184V mutations, and standard genotypic sequencing were assayed. Results No mutations associated with resistance to 3TC or NVP were found by standard population sequencing. Analysis of K103N by SPCR showed that 35% of the patients contained ≤0.1% of viruses carrying either the AAC or AAT mutations. For Y181C mutation, 10% of the patients contained <0.5% of viruses with TGT codon change. For M184V mutation, one patient contained 6.2% of virus with GTG mutation and 13 patients (65%) contained <0.9% of mutated viruses. Four women were re-exposed to 3TC/ZDV/NVP and achieved HIV VL <50 copies/ml. No perinatal transmission occurred in any of the 22 births. Conclusions NVP associated with ZDV/3TC as a regimen to prevent MTCT may involve a low risk for the selection of antiretroviral-resistant strains and may not jeopardize the use of these same drugs for future treatment.
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    Prevalence of cryptococcal infection among advanced HIV patients in Argentina using lateral flow immunoassay
    (2017-06-15) Frola, Claudia; Guelfand, Liliana; Blugerman, Gabriela; Szyld, Edgardo; Kaufman, Sara; Cahn, Pedro; Sued, Omar; Pérez, Héctor
    Background Globally, Latin America ranks third among regions with most cases of AIDS related cryptococcal meningitis. In 2009, a lateral flow immunoassay (LFA) for the detection of cryptococcal antigen (CrAg) was developed as a potential point-of-care test for diagnosis of cryptococcal infection. In 2011 World Health Organizations recommended on CrAg screening for HIV positive persons with CD4 below 100 cells/μL, followed by preemptive fluconazole treatment. However, in Argentina no formal recommendations for CrAg screening have been issued. Methods HIV positive patients > = 18 years with advanced immunosuppression (CD4 counts ≤100 cells/μL within 3 months or WHO stage III/IV), who visited the hospital between April 1, 2014 and January 31, 2015, were included. The LFA was performed according to the manufacturer’s instructions on all serum samples. When CrAg detection was positive, a lumbar puncture was performed to rule out cryptococcal meningitis. Patients without evidence of meningeal involvement were treated with preemptive oral fluconazole in ambulatory care. Results We included 123 patients. Prevalence of CrAg-positivity was 8.1%. Among the 10 CrAg-positive patients, 6 had meningeal involvement detected through the CSF analysis (CSF India-ink testing, CSF CrAg and culture). The remaining 4 patients with positive CrAg received targeted preemptive treatment with oral fluconazole and were free of cryptococcal disease during the follow-up period. None of the 113 patients with a negative CrAg test result developed cryptococcal disease. Conclusions This is the first study in Argentina, to our knowledge, describing the prevalence of cryptococcosis and usefulness of CrAg screening. LFA provided early diagnosis to determine a high prevalence of CrAg in our hospital, and that screening for subclinical infection with preemptive antifungal treatment, prevented a substantial proportion of meningeal disease.
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    Prueba piloto de validación del método portátil PIMA para el recuento de células CD4 en comparación con la citometría de flujo.
    (2015-04) Sued, Omar; Salgado, Pablo; Picchio, Camila; Figueroa, Maria Ines; Socias, Maria E.; Cando, Osvaldo; Díaz, Liliana; Hermes, Ricardo; Pérez, Héctor; Cahn, Pedro
    Objetivo: comparar la metodología PIMA con la citometría de flujo convencional para el recuento de linfocitos CD4 en pacientes con infección por HIV. Métodos: se realizaron determinaciones pareadas en sangre venosa de pacientes con HIV y se comparó la correlación entre ambos resultados. Resultados: se realizaron 223 determinaciones en forma pareadas. La concordancia fue muy buena, con una correlación lineal de Pearson de 0,974, correlación por rangos de Spearman de 0,971 y con un coeficiente de determinación lineal (R cuadrado) de 0,949 (p < 0,01). El coeficiente de correlación intraclases para las medidas individuales fue de 0,965 (IC 95 % 0,926-0,980) y para medidas promedio 0,982 (IC95 % 0,961-0,990). El coeficiente de variación para medidas duplicadas fue bajo siendo 11,4 %. Discusión: este estudio demuestra una buena correlación entre la determinación de células CD4 con el sistema PIMA frente a la citometría de flujo y apoya el uso de estas metodologías donde no hay acceso a citometría convencional.
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    Safe Treatment Interruptions in Patients With Nadir CD4 Counts of More Than 350 Cells/μL
    (2006-04-01) Krolewiecki, Alejandro J.; Zala, Carlos; Vanzulli, Claudia; Pérez, Héctor; Iannella, María del Carmen; Bouzas, María Belén; Gun, Ana; Valiente, José; Cassetti, Isabel; Cahn, Pedro
    Objective: To evaluate clinical, immunologic, and virologic performance of patients with nadir CD4 counts of >350cells/μL upon treatment interruption. Design: Randomized, open-label clinical trial of 48 weeks' duration. Methods: Patients on effective highly active antiretroviral therapy, with nadir CD4 counts of >350 cells/μL and peak viral loads of <50,000 copies/mL were randomized to continue therapy or to interrupt antiretroviral medication. End points for patients with treatment interruption were CD4 counts of <350 cells/μL, viral loads of >1 log above the pretherapy values, or clinical symptoms attributable to HIV, at which point treatment was restarted. In the continuation group, the end points were virologic failure, opportunistic infections, and treatment discontinuation due to toxicities. Results: Twenty patients were randomized to stop therapy and 16 patients to continue. Median CD4 counts at baseline were 643 cells/μL for the interruption group and 633 cells/μL for the continuation group. No end points were reached in the interruption group. By week 8, viral load returned to values comparable to those of pretherapy in all patients in the interruption group and remained stable until week 48. CD4 counts dropped in the interruption group (median loss of 156 cells/μL) at week 48. Significant decreases in venous lactate were observed in the interruption group. Conclusions: Treatment interruptions in patients with nadir CD4 counts of >350 cells/μL seem safe for at least 48 weeks. Pretherapy viral load appears as a valuable tool to predict its level at week 48.
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    The HIV care cascade in Buenos Aires, Argentina: results in a tertiary referral hospital
    (2016-12) Cesar, Carina; Blugerman, Gabriela; Valiente, José Antonio; Rebeiro, Peter; Sued, Omar; Fink, Valeria; Romero Soto, Mariana; Cillis, Roberto; Yamamoto, Cleyton; Falistocco, Carlos; Cahn, Pedro; Pérez, Héctor
    Objective: To determine rates of retention, antiretroviral therapy (ART) use, and viral suppression in an adult cohort from a public tertiary referral hospital in the city of Buenos Aires, Argentina. Methods: HIV-positive ART-naïve patients ≥ 18 years old starting care 2011-2013 contributed data until the end of 2014. Three outcomes were assessed in 2014: retention in care, ART use, and viral suppression. Patient characteristics associated with each outcome were assessed through logistic regression. Results: A total of 1 031 patients were included. By the end of 2014, 1.5% had died and 14.8% were transferred to a different center. Of the remaining 859 patients, 563 (65.5%) were retained in 2014. Among those retained, 459 (81.5%) were on ART in 2014. Of those 459 on ART, 270 (58.8%) were virologically suppressed. Younger age was associated with lower retention (OR (odds ratio): 0.67; 95% CI (confidence interval): 0.44-0.92 for ≥ 35 vs. < 35 years), but unrelated with ART use or viral suppression. Low CD4 count at first visit was associated with ART use (OR: 35.72 for CD4 < 200, 7.13 for CD4 200-499 vs. ≥ 500, P < 0.001) and with virologic suppression (OR: 2.17 for CD4 < 200, 2.46 for CD4 200-499 vs. ≥ 500, P: 0.023). Conclusions: Our hospital in Buenos Aires is still below the recommended 90-90-90 targets of the Joint United Nations Programme on HIV/AIDS (UNAIDS) for ART use and viral suppression. We found a major gap in retention in care. Identifying younger age as being associated with worse retention will help in the design of targeted interventions.
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    The intestinal mucosa as a reservoir of HIV-1 infection after successful HAART
    (2007-10-01) Belmonte, Liliana; Olmos, Martin; Fanin, Ana; Parodi, Cecilia; Baré, Patricia; Concetti, Hugo; Pérez, Héctor; de Bracco, Maria Marta E; Cahn, Pedro
    The presence of HIV-1 RNA in distal duodenal mucosa was evaluated in 44 HIV-1-positive patients. HIV-1 RNA was detected in gut tissue in antiretroviral-naive patients with high plasma viral loads, as well as in patients on HAART with plasma viral loads below the limit of detection and in patients on HAART with virological failure. The intestinal mucosa seems to serve as a reservoir poorly influenced by levels of plasma viral load or HAART.