Low dose thymoglobulin versus basiliximab in cytomegalovirus positive kidney transplant recipients: Effectiveness of preemptive cytomegalovirus modified strategy / Timoglobulina en dosis bajas vs. basiliximab en receptores de trasplante renal positivos para citomegalovirus: efectividad de una estrategia preventiva modificada

Background: We performed a retrospective trial to determine asymptomatic CMV reactivation and CMV disease in kidney allograft recipients with positive CMV serostatus. Methods: Preemptive modified strategy under low dose thymoglobulin versus basiliximab induction was evaluated. Patients were monitored by CMV-polymerase chain reaction (PCR); if the viral load was >4000copies/μl, they received valganciclovir adjusted for their renal function. Results: 132 recipients were included in the study, 84 and 48 receiving basiliximab and thymoglobulin induction respectively, and followed up for 12 months. Asymptomatic CMV reactivation was significantly higher for thymoglobulin (77.1% vs. 16.7%, p<0.001). Treatment groups had similar rates of CMV disease (3.6% vs. 2.1%, p 0.538). The significant difference in asymptomatic CMV reactivation between two treatment groups did not have any impact on 1 year graft function (71±26ml/min vs. 74±19ml/min; p=0.475) and no histological differences in protocol biopsies were observed among patients with asymptomatic CMV reactivation vs those without CMV reactivation. Conclusions: Due to the high asymptomatic CMV reactivation incidence in patients who received thymoglobulin induction, our results suggest that valganciclovir prophylaxis may be advantageous in CMV seropositive renal transplant recipients after low dose thymoglobulin induction. A preemptive strategy appeared to significantly reduce the likelihood of CMV disease in both groups. Rejection risk and negative impact in renal function associated with asymptomatic CMV reactivation was not found in our series. (AU)

Antecedentes: Llevamos a cabo un estudio retrospectivo para determinar la reactivación y enfermedad por CMV en receptores de trasplante renal CMV seropositivos bajo diferentes esquemas de inducción. Métodos: Una estrategia preventiva modificada bajo inducción con basiliximab y timoglobulina en dosis bajas fue evaluada. Se llevó a cabo un seguimiento de la carga viral-reacción de cadena de la polimerasa-CMV; los valores mayores de 4000 copias/μl recibieron valganciclovir ajustado a la función renal. Resultados: Un total de 132 receptores de trasplante renal fueron incluidos; 84 y 48 recibieron inducción con basiliximab y timoglobulina respectivamente. Seguimiento hasta el mes 12 postrasplante. La reactivación asintomática de CMV fue significativamente mayor para timoglobulina (77,1% vs. 16,7%, p<0,001). La tasa de enfermedad por CMV fue similar en ambos grupos de tratamiento (3,6% vs. 2,1%, p=0,538). Ningún impacto en la función renal un año postrasplante fue encontrado entre los grupos a pesar de la diferencia significativa en reactivación asintomática de CMV (71±26ml/min vs. 74±19ml/min; p=0,475); igualmente, no encontramos diferencias en los hallazgos histológicos en biopsias por protocolo entre receptores con reactivación asintomática por CMV y aquellos sin reactivación. Conclusiones: La alta incidencia de reactivación asintomática por CMV en receptores seropositivos a pesar del uso de bajas dosis de timoglobulina sugiere que la profilaxis con valganciclovir es una estrategia apropiada en este grupo; sin embargo, una estrategia preventiva reduce significativamente la probabilidad de enfermedad por CMV en ambos grupos de tratamiento. El riesgo de rechazo y el impacto negativo en la función renal asociado a la reactivación asintomática por CMV no fue encontrado en nuestra experiencia.

Low dose thymoglobulin versus basiliximab in cytomegalovirus positive kidney transplant recipients: Effectiveness of preemptive cytomegalovirus modified strategy.

BACKGROUND: We performed a retrospective trial to determine asymptomatic CMV reactivation and CMV disease in kidney allograft recipients with positive CMV serostatus. METHODS: Preemptive modified strategy under low dose thymoglobulin versus basiliximab induction was evaluated. Patients were monitored by CMV-polymerase chain reaction (PCR); if the viral load was >4000copies/µl, they received valganciclovir adjusted for their renal function. RESULTS: 132 recipients were included in the study, 84 and 48 receiving basiliximab and thymoglobulin induction respectively, and followed up for 12 months. Asymptomatic CMV reactivation was significantly higher for thymoglobulin (77.1% vs. 16.7%, p<0.001). Treatment groups had similar rates of CMV disease (3.6% vs. 2.1%, p 0.538). The significant difference in asymptomatic CMV reactivation between two treatment groups did not have any impact on 1 year graft function (71±26ml/min vs. 74±19ml/min; p=0.475) and no histological differences in protocol biopsies were observed among patients with asymptomatic CMV reactivation vs those without CMV reactivation. CONCLUSIONS: Due to the high asymptomatic CMV reactivation incidence in patients who received thymoglobulin induction, our results suggest that valganciclovir prophylaxis may be advantageous in CMV seropositive renal transplant recipients after low dose thymoglobulin induction. A preemptive strategy appeared to significantly reduce the likelihood of CMV disease in both groups. Rejection risk and negative impact in renal function associated with asymptomatic CMV reactivation was not found in our series.

Análisis proteómico del veneno de la abeja africanizada: comparación de métodos de extracción / Proteomic Analysis of Africanized Bee Venom: a Comparison of Protein Extraction Methods

La abeja africanizada es la más común en la apicultura colombiana y a su veneno (apitoxina) se le han atribuido propiedades terapéuticas para diferentes enfermedades, sin mayor soporte científico. Al revisar en la literatura los reportes publicados sobre el análisis proteómico de la apitoxina, se encontraron cuatro métodos distintos para la extracción de proteínas de la apitoxina. El primer método consiste en resuspender la apitoxina en Urea 7 M, precipitar con acetona y finalmente resuspender en Urea 7 M y CHAPS 4 %. Para el segundo método se resuspende la apitoxina en buffer de lisis, se precipita con ácido tricloroacético, y luego se resuspende en Urea 7 M y CHAPS 4 %. El tercer método es igual al anterior, excepto que la precipitación se realiza con acetona en vez de ácido tricloroacético. Finalmente, el cuarto método consiste en resuspender la apitoxina en agua destilada, precipitar con acetona y resuspender en Urea 7 M y CHAPS 4 %. Este trabajo se enfocó en comparar el desempeño de estos cuatro métodos de extracción y determinar el método con el mejor resultado en cuanto a la concentración e integridad obtenida de las proteínas. De los distintos métodos evaluados, se encontró que los mejores resultados en cuanto a concentración de proteínas se obtuvieron con la resuspensión de apitoxina en buffer de lisis y precipitación con acetona (método 3) y con el método de resuspensión de apitoxina en agua destilada y precipitación con acetona (método 4). De estos, el mejor método de extracción en cuanto a integridad de las proteínas y perfil proteómico fue el de resuspensión de apitoxina en buffer de lisis seguido de precipitación con acetona (método 3).

The Africanised bee is the most common type of bee in Colombia, and therapeutic properties for different diseases have been attributed to its venom, without much scientific support. A literature search of reports on the proteomic analysis of honeybee venom yielded four different methods for extracting proteins from bee venom. The first method consists in resuspending the venom in 7 M Urea, followed by precipitation with acetone and finally resuspending the pellet in 7 M Urea and 4 % CHAPS. For the second method, the venom is resuspended in lysis buffer, precipitated with trichloroacetic acid, and then resuspended in 7 M Urea and 4 % CHAPS. The third method is similar to the previous one, except that the precipitation step is performed with acetone instead of trichloroacetic acid. Finally, the fourth method is to resuspend the venom in distilled water, precipitate with acetone and resuspend in 7 M Urea and 4 % CHAPS. This work focused on comparing the performance of these four extraction methods, in order to determine the method with the best results in terms of concentration and integrity of the proteins obtained. Of the four methods evaluated, the best results in terms of protein concentration and yield were obtained by resuspending the bee venom in lysis buffer followed by precipitation with acetone (method 3), and by resuspending in distilled water followed by precipitation with acetone (method 4). Of these, the method that maintained protein integrity and yielded the best proteomic profile was that in which the bee venom was resuspended in lysis buffer followed by precipitation with acetone (method 3).