Severe dengue pathogenesis is not fully understood, but high levels of proinflammatory cytokines have been associated with dengue disease severity. In this study, the cytokine levels in 171 sera from Mexican patients with primary dengue fever (DF) and dengue haemorrhagic fever (DHF) from dengue virus (DENV) 1 (n = 116) or 2 (n = 55) were compared. DF and DHF were defined according to the patient’s clinical condition, the primary infections as indicated by IgG enzymatic immunoassay negative results, and the infecting serotype as assessed by real-time reverse transcription-polymerase chain reaction. Samples were analysed for circulating levels of interleukin (IL)-12p70, interferon (IFN)-γ, tumour necrosis factor (TNF)-α, IL-6, and IL-8 using a commercial cytometric bead array. Significantly higher IFN-γ levels were found in patients with DHF than those with DF. However, significantly higher IL-12p70, TNF-α, and IL-6 levels were associated with DHF only in patients who were infected with DENV2 but not with DENV1. Moreover, patients with DF who were infected with DENV1 showed higher levels of IL-12p70, TNF-α, and IL-6 than patients with DHF early after-fever onset. The IL-8 levels were similar in all cases regardless of the clinical condition or infection serotype. These results suggest that the association between high proinflammatory cytokine levels and dengue disease severity does not always stand, and it once again highlights the complex nature of DHF pathogenesis.

OBJECTIVE: To measure the incidence rate and trend of acute leukemia (AL) in political districts of Mexico City. MATERIAL AND METHODS: Descriptive longitudinal study conducted at six hospitals that care for nearly 97.5% of all cancer cases among children in Mexico City. Study data were collected in 1995 and 1996, and were analyzed in 1999, at the National Medical Center "Siglo XXI" Children's Hospital, of the Mexican Institute for Social Security. Calculations of acute leukemia annual incidence rates, standardized rates, and standardized morbidity rates (SMR) with 95% confidence intervals, were obtained for each district. Morbidity trends were assessed through average change rates. RESULTS: In this study we observed an increasing trend of acute lymphoblastic leukemia (ALL) incidence in five districts: Alvaro Obregon, Cuauhtemoc, Gustavo A. Madero, Iztacalco, and Venustiano Carranza. Acute myeloblastic leukemia (AML) showed no significantly statistic increase of incidence in any district. AML did show a significant SMR in Alvaro Obregon district (SMR= 2.91, 95% CI 1.63 - 4.80). Higher SMRs were found in the south and southwest areas of the city. CONCLUSIONS: Increasing incidence of ALL was observed in five districts of Mexico City. AML incidence was the highest in Alvaro Obregon district.

OBJETIVO: Medir la tasa de incidencia de las leucemias agudas (LA) en las diferentes delegaciones políticas del Distrito Federal y evaluar si existe una tendencia significativa en dichos padecimientos en tales delegaciones. MATERIAL Y MÉTODOS: Estudio longitudinal descriptivo realizado en seis hospitales de la ciudad de México, los que atienden a cerca de 97.5% de todos los niños con cáncer de esta ciudad. Los datos se capturaron de 1995 a 1996, y se analizaron en 1999, en el Hospital de Pediatría del Centro Médico Nacional Siglo XXI, del Instituto Mexicano del Seguro Social. Para cada delegación se calcularon la tasa de incidencia anual promedio, la tasa estandarizada y la razón estandarizada de morbilidad (REM) con intervalos de confianza al 95% (IC 95%). La tendencia se evaluó con la tasa de cambio promedio. RESULTADOS: Se observó una tendencia al incremento en la incidencia de la leucemia aguda linfoblástica (LAL) en cinco delegaciones: Alvaro Obregón, Cuauhtémoc, Gustavo A. Madero, Iztacalco y Venustiano Carranza. En la leucemia aguda mieloblástica (LAM) no se notificaron cambios estadísticamente significativos en la incidencia en ninguna delegación política. Sólo con LAM se encontró una REM significativa y correspondió a la delegación Alvaro Obregón (REM= 2.91, IC 95% 1.63 - 4.80). Las REM más altas se encontraron en el sur y suroeste de la ciudad. CONCLUSIONES: Sólo se observó incremento en la incidencia de LAL en cinco delegaciones políticas. La incidencia más alta de LAM se encontró en la delegación Alvaro Obregón.