Effect of maternal Tdap on infant antibody response to a primary vaccination series with whole cell pertussis vaccine in São Paulo, Brazil.

BACKGROUND: Maternal Tetanus, diphtheria, and acellular pertussis (Tdap) vaccination provides antibody transfer to newborn infants and may affect their antibody response to the primary vaccination series. This study aimed to assess the effect of Tdap vaccination during pregnancy on infant antibody response to the whole cell pertussis (DTwP) primary series. METHODS: Plasma from 318 pregnant women (243 Tdap-vaccinated and 75 unvaccinated) and their infants (cord blood) was collected at delivery; infant blood was again collected at 2 and 7 months, before and after their primary DTwP series. Anti-pertussis toxin (PT), pertactin (PRN), filamentous hemagglutinin (FHA), fimbriae 2/3 (FIM) and adenylate cyclase toxin (ACT) IgG antibodies were quantified by a microsphere-based multiplex antibody capture assay and anti-PT neutralizing antibodies by the Real Time Cell analysis system. RESULTS: Infant geometric mean concentrations (GMCs) of IgG anti-Tdap antigens were significantly higher (p < 0.001) among the Tdap-vaccinated (PT: 57.22 IU/mL; PRN: 464.86 IU/mL; FHA: 424.0 IU/mL), versus the unvaccinated group (4 IU/mL, 15.43 IU/mL, 31.99 IU/mL, respectively) at delivery. Anti-FIM and ACT GMCs were similar between the two groups. At 2 months of age, anti-PT, PRN, and FHA GMCs remained higher (p < 0.001) in the Tdap-vaccinated group (12.64 IU/mL; 108.76 IU/mL; 87.41 IU/mL, respectively) than the unvaccinated group (1.02 IU/mL; 4.46 IU/mL; 6.89 IU/mL). However, at 7 months, after receiving the third DTwP dose, the anti-PT GMC was higher (p = 0.016) in the unvaccinated group (7.91 IU/mL) compared to the vaccinated group (2.27 IU/mL), but without differences for anti-PRN, FHA, FIM and ACT GMCs. CONCLUSION: Elevated antibody levels suggest that maternal Tdap vaccination might protect infants until 2 months of age. Reduced anti-PT levels at 7 months indicate potential blunting of immune response in infants. Surveillance would help determine if blunting alters vaccine immunity and impacts pertussis prevention in infants.

Adverse event occurrence following use of tetanus, diphtheria and acellular pertussis adsorbed vaccine - Tdap -, São Paulo, SP, Brazil, 2015-2016. / Ocorrência de eventos adversos após o uso da vacina adsorvida difteria, tétano e pertussis (acelular) ­ dTpa ­, São Paulo, SP, 2015-2016.

Objective to describe occurrence of adverse events following immunization (AEFI) with Tdap vaccine during pregnancy. Methods this was a descriptive study using data from reports by participants in an effectiveness and immunogenicity study conducted in two hospitals in São Paulo, SP, Brazil, from 2015 to 2016. Results of the 201 mothers included in the study, 48 (23.9%) had at least one AEFI; 60 symptoms related to Tdap use were identified - pain (22.4%), swelling (2.5%), fever (1.5%), somnolence (1.0%), redness (0.5%), vomiting (0.5%), headache (0.5%), local reaction (0.5%), and fatigue (0.5%); no rare, very rare, or extremely rare adverse events were reported; all events were considered to be expected, as they are described in the vaccine package insert; outcome of all events was recovery without sequelae. Conclusion Tdap vaccine in the form adopted by the National Immunization Program is safe; no unexpected adverse events were identified among vaccinated pregnant women.

Ocorrência de eventos adversos após o uso da vacina adsorvida difteria, tétano e pertussis (acelular) - dTpa -, São Paulo, SP, 2015-2016 / Aparecimiento de eventos adversos después del uso de la vacuna adsorbida difteria, tétanos y tosferina (acelular) - dTpa -, São Paulo, SP, Brasil, 2015-2016 / Adverse event occurrence following use of tetanus, diphtheria and acellular pertussis adsorbed vaccine - Tdap -, São Paulo, SP, Brazil, 2015-2016

Objetivo: descrever a ocorrência de eventos adversos pós-vacinação (EAPV) com a vacina dTpa durante a gestação. Métodos: estudo descritivo, com dados de relatos das participantes de estudo de efetividade e imunogenicidade realizado em dois hospitais de São Paulo, SP, Brasil, entre 2015 e 2016. Resultados: das 201 mães incluídas no estudo, 48 (23,9%) apresentaram pelo menos um EAPV; foram identificados 60 sintomas relacionados ao uso da dTpa - dor (22,4%), inchaço (2,5%), febre (1,5%), sono (1,0%), vermelhidão (0,5%), vômito (0,5%), dor de cabeça (0,5%), reação local (0,5%) e cansaço (0,5%); não foram registrados eventos adversos raros, muito raros ou extremamente raros; todos os eventos foram considerados esperados e estão descritos em bula; todos tiveram desfecho para cura sem sequelas. Conclusão: a dTpa, na forma adotada pelo Programa Nacional de Imunizações (PNI), é segura; não foram identificados eventos adversos inesperados entre as gestantes imunizadas com a vacina.

Objetivo: describir el aparecimiento de eventos adversos posvacunación (EAPV) con la vacuna dTpa durante el embarazo. Métodos: estudio descriptivo con datos de relatos de las participantes del estudio de efectividad e inmunogenicidad realizado en dos hospitales de São Paulo, SP, Brasil, entre 2015 y 2106. Resultados: de las 201 madres del estudio, 48 (23,9%) tuvieron al menos un EAPV; se identificaron 60 síntomas relacionados al uso de dTpa - dolor (22.4%), hinchazón (2.5%), fiebre (1.5%), somnolencia (1.0%), enrojecimiento (0.5%), vómitos (0.5 %), dolor de cabeza (0.5%), reacción local (0.5%) y cansancio (0.5%) -; no se informaron eventos adversos raros, muy raros o extremadamente raros; todos los eventos se consideraron esperados y se describen en el prospecto; todos tuvieron resultados curativos sin secuelas. Conclusión: el estudio mostró que la vacuna dTpa utilizada por el Programa Nacional de Inmunización (PNI) es segura y no se identificaron eventos adversos inesperados entre las mujeres embarazadas vacunadas.

Objective: to describe occurrence of adverse events following immunization (AEFI) with Tdap vaccine during pregnancy. Methods: this was a descriptive study using data from reports by participants in an effectiveness and immunogenicity study conducted in two hospitals in São Paulo, SP, Brazil, from 2015 to 2016. Results: of the 201 mothers included in the study, 48 (23.9%) had at least one AEFI; 60 symptoms related to Tdap use were identified - pain (22.4%), swelling (2.5%), fever (1.5%), somnolence (1.0%), redness (0.5%), vomiting (0.5%), headache (0.5%), local reaction (0.5%), and fatigue (0.5%); no rare, very rare, or extremely rare adverse events were reported; all events were considered to be expected, as they are described in the vaccine package insert; outcome of all events was recovery without sequelae. Conclusion: Tdap vaccine in the form adopted by the National Immunization Program is safe; no unexpected adverse events were identified among vaccinated pregnant women.

Adverse event occurrence following use of tetanus, diphtheria and acellular pertussis adsorbed vaccine – Tdap –, São Paulo, SP, Brazil, 2015-2016 / Ocorrência de eventos adversos após o uso da vacina adsorvida difteria, tétano e pertussis (acelular) – dTpa –, São Paulo, SP, 2015-2016 / Aparecimiento de eventos adversos después del uso de la vacuna adsorbida difteria, tétanos y tosferina (acelular) – dTpa –, São Paulo, SP, Brasil, 2015-2016

Objective: to describe occurrence of adverse events following immunization (AEFI) with Tdap vaccine during pregnancy. Methods: this was a descriptive study using data from reports by participants in an effectiveness and immunogenicity study conducted in two hospitals in São Paulo, SP, Brazil, from 2015 to 2016. Results: of the 201 mothers included in the study, 48 (23.9%) had at least one AEFI; 60 symptoms related to Tdap use were identified – pain (22.4%), swelling (2.5%), fever (1.5%), somnolence (1.0%), redness (0.5%), vomiting (0.5%), headache (0.5%), local reaction (0.5%), and fatigue (0.5%); no rare, very rare, or extremely rare adverse events were reported; all events were considered to be expected, as they are described in the vaccine package insert; outcome of all events was recovery without sequelae. Conclusion: Tdap vaccine in the form adopted by the National Immunization Program is safe; no unexpected adverse events were identified among vaccinated pregnant women.

Objetivo: descrever a ocorrência de eventos adversos pós-vacinação (EAPV) com a vacina dTpa durante a gestação. Métodos: estudo descritivo, com dados de relatos das participantes de estudo de efetividade e imunogenicidade realizado em dois hospitais de São Paulo, SP, Brasil, entre 2015 e 2016. Resultados: das 201 mães incluídas no estudo, 48 (23,9%) apresentaram pelo menos um EAPV; foram identificados 60 sintomas relacionados ao uso da dTpa – dor (22,4%), inchaço (2,5%), febre (1,5%), sono (1,0%), vermelhidão (0,5%), vômito (0,5%), dor de cabeça (0,5%), reação local (0,5%) e cansaço (0,5%); não foram registrados eventos adversos raros, muito raros ou extremamente raros; todos os eventos foram considerados esperados e estão descritos em bula; todos tiveram desfecho para cura sem sequelas. Conclusão: a dTpa, na forma adotada pelo Programa Nacional de Imunizações (PNI), é segura; não foram identificados eventos adversos inesperados entre as gestantes imunizadas com a vacina.

Association between the timing of maternal vaccination and newborns' anti-pertussis toxin antibody levels.

BACKGROUND: Pertussis remains an important global public health concern, despite the presence of extensive immunization programs. Incidence and severity of pertussis are typically higher in neonates and young infants. As a strategy to protect these young infants, maternal vaccination with Tdap (tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis) has been recommended in Brazil. The objective of this study was to evaluate the effects of Tdap vaccination during pregnancy on the anti-pertussis toxin (PT) IgG response in mothers and their infants at birth. MATERIAL AND METHODS: Maternal and cord blood samples were collected from vaccinated (n = 243) and unvaccinated (n = 75) pregnant women, at the time of delivery, from July 2015 to August 2016 in São Paulo, Brazil. Anti-PT IgG antibodies were quantified by Enzyme-Linked Immunosorbent Assay (ELISA) and geometric mean concentrations (GMC) were calculated. Relationship between timing of vaccination and antibody concentrations were evaluated. RESULTS: Maternal and cord blood GMCs among the vaccinated group were 5.4 and 5.6 fold higher [66.5 International Units (IU)/mL and 89.8 IU/mL] compared to the unvaccinated group (12.4 IU/mL and 16.1 IU/mL), respectively (p < 0.001). Higher anti-PT IgG GMCs were observed when vaccination occurred ≥60 days before delivery compared to <60 days, suggesting that vaccination early in the third trimester may be more effective than later in pregnancy. CONCLUSION: Tdap maternal vaccination results in significantly higher anti-PT IgG in newborn infants and supports the current recommendation of the Brazilian Immunization Program.

The effectiveness of maternal pertussis vaccination in protecting newborn infants in Brazil: A case-control study.

INTRODUCTION: In 2014, the Brazilian Ministry of Health (MoH) recommended Tdap to pregnant women in response to a significant increase in the incidence of pertussis among infants. The present study assessed the effectiveness of maternal immunization in preventing pertussis in infants. METHODS: An unmatched case-control study was undertaken in São Paulo State, Brazil from February 2015 to July 2016. Cases were infants aged <8 weeks at onset of pertussis reported to the Surveillance System and confirmed by real-time polymerase chain reaction or culture. Four to six healthy infants were selected as controls per case from birth certificates in the Information System on Live Births database. General characteristics and mother's vaccination status were compared between cases and controls. The vaccine effectiveness (VE) was calculated as 1 - odds ratio (OR). For the adjusted VE, the OR was calculated using logistic regression analysis. RESULTS: Forty-two cases and 248 controls were enrolled in the study. Mothers of 8 cases (19.1%) and 143 controls (57.4%) were vaccinated during pregnancy, resulting in an unadjusted VE of 82.6% (95% confidence interval [CI], 60.8-92.3%). The VE was unchanged after adjusting for maternal age and monthly household income. CONCLUSION: Maternal pertussis vaccination during pregnancy was effective in protecting infants aged <8 weeks from pertussis.

Temporal trends and molecular epidemiology of HIV type 1 infection in Rio de Janeiro, Brazil.

HIV-1 molecular epidemiology studies carried out in Rio de Janeiro, Brazil have identified the prevalence of subtypes B, F1 and BF1 recombinants. A high percentage of HIV-1 subtype B isolates in Rio de Janeiro harbor the GWG motif at the V3 tip (B'' variant) instead of the canonical GPG motif (B variant). To trace the dynamics of the HIV-1 variants over time in different exposure categories in Rio de Janeiro, the HIV-1 proviral DNA from heterosexual men (HET) and men who have sex with men (MSM) from two distinct time periods (1990-1992 and 2008-2010) were extracted, and the env-gp120 region was amplified. Neighbor-joining phylogenetic analysis was performed to determine the viral subtype, and Bayesian analysis was used to trace the HIV-1 transmission networks. A predominance of subtype B was observed in both study periods, independent of the exposure risk category. An increase of non-B subtypes was observed in the HET group, but these subtypes were maintained among the MSM group. The distribution of HIV-1 subtype B signatures in the first and second periods studied were, respectively, HET (GPG) [44.8-51.5%], (GWG) [13.8-33.3%], and (GXG) [41.4-15.2%] and MSM (GPG) [34-50%], (GWG) [55.3-30.6%], and (GXG) [10.7-19.4%]. In the first period, an association between GWG and MSM was verified while a significant reduction of this association was observed during the second period. The phylogenetic tree and the BaTS program detected the clustering of isolates only according to the B signatures but not by exposure risk category. Our findings indicate a stable prevalence of HIV-1 subtypes B and F over time in Rio de Janeiro and further suggest that the B'' subclade of subtype B was possibly introduced into the MSM group in this area of Brazil.

Effectiveness of the polysaccharide pneumococcal vaccine among HIV-infected persons in Brazil: a case control study.

BACKGROUND: Polysaccharide pneumococcal vaccine is recommended for use in HIV-infected adults in Brazil but there is uncertainty about its effectiveness in this patient population. The main objective of this study was to assess the effectiveness of the 23-valent polysaccharide pneumococcal vaccine against invasive pneumococcal infection among HIV-infected adult patients in São Paulo, Brazil. METHODS: A case-control study of 79 cases and 242 controls matched on CD4+ cell count and health care setting was conducted. Among HIV-infected adults in São Paulo, Brazil, with and without S. pneumoniae recovered from a normally sterile site; prior receipt of 23 valent polysaccharide pneumococcal vaccine was determined by review of medical records and patient interview. RESULTS: After adjustment for confounding factors, the point estimate for the effectiveness of 23 valent polysaccharide vaccine among HIV-infected adults against all invasive pneumococcal infection was 18% (95% CI: <0 to 62%). CONCLUSION: We were unable to demonstrate a statistically significant protective effect of 23 valent polysaccharide against invasive pneumococcal infection vaccine among HIV-infected adults in Brazil.While the vaccine is relatively inexpensive and safe, its effectiveness among HIV-infected adults in Brazil is uncertain.

Os caminhos da estatística e suas incursoes pela epidemiologia / The paths of statistics and its incursions through epidemiology

Contempla-se o desenvolvimento da estatística, desde suas origens probabilísticas até os atuais modelos de "dependência" no tempo e no espaço. Avalia-se a evoluçao do método quantitativo na abordagem epidemiológica, como também procura-se estabelecer limites das técnicas estatísticas habituais, discutindo-se suas suposiçoes teóricas e sua adequaçào ao tratamento analítico das informaçoes. Enfatizam-se a importância do desenvolvimento e/ou generalizaçao de procedimentos que possam ajudar a superar as dificuldades metodológicas ainda encontradas em diversos estudos de inferência causal em epidemiologia

Diferenciais regionais de mortalidade por câncer no Estado do Rio de Janeiro, Brasil, 1979-1981 / Regional differentials in cancer mortality in a region of Brazil, 1979-1981

A partir do fato de que os neoplasmas malígnos foram a terceira causa de morte no Estado do Rio de Janeiro, Brasil, no ano de 1980, apresentando taxa bruta igual a 89,8 por 100.000 habitantes, foi analisada a mortalidade por câncer segundo suas principais localizaçöes anatômicas, no período 1979-1981. Dividiu-se o Estado em três regiöes distintas: Capital, Cinturäo Metropolitano e Interior. Foram calculados coeficientes de mortalidade trienais, posteriormente padronizados pelo método direto utilizando-se, para tal, a populaçäo mundial. Para cumprir o objetivo de comparar diferentes regiöes geográficas foram calculadas razöes padronizadas de mortalidade. Observou-se que as principais localizaçöes anatômicas foram pulmäo, estômago, próstata, esôfago e fígado, nos homens; e mama, estômago, pulmäo, cérvix uterino e útero (näo especificado), nas mulheres. Encontrou-se que as maiores taxas para o total de tumores ocorreram na Capital e as menores no Interior, sendo que as maiores razöes padronizadas de mortalidade aquelas para mama (1,88), cólon (1,71) e pulmäo (1,70). A mortalidade por neoplasmas malígnos de esôfago e de fígado foi maior no Interior do que nas demais regiöes, em ambos os sexos. Conclui-se que existe comportamento distinto da mortalidade por câncer entre as diferentes regiöes, apontando, mais uma vez, na direçäo da determinaçäo ambiental de grande parte dos neoplasmas malígnos

Diagrama de verificación para evaluar reactivos de hemaglutinación usados en el diagnóstico de la enfermedad de Chagas / A control chart method for evaluating hemagglutination reagent used in Chagas' disease diagnosis

Se describe la técnica del diagrama de verificación, menos complicada y más apta que la técnica de análisis secuencial para evaluar lotes pequeños de reactivo

En este método se necesitan un reactivo de referencia, un conjunto de alrededor de 20 muestras de suero y un límite establecido de la varianza que, cuando es sobrepasado, determina el rechazo del lote puesto a prueba. La mitad de las muestras de suero deben ser reactivas con respecto al antígeno de Trypanosoma cruzi y la otra mitad deben ser no reactivas; los sueros reactivos tienen que ser útiles en el sentido que su respuesta ante un reactivo de buena calidad (como el de referencia) es distinta de la que manifiestan ante un mal reactivo

Con este procedimiento, el reactivo de referencia y el reactivo que se quiere evaluar se ponen a prueba con el conjunto de muestras de suero; se observan las diferencias entre los títulos obtenidos con los dos reactivos y se calcula la desviación estándar promedio. Cuando esta es inferior al límite de verificación previamente establecido, el lote de reactivo es aceptado; si supera el límite, se rechaza el lote. La experiencia del Laboratorio de Inmunología del Instituto de Medicina Tropical de Sao Paulo, Brasil, ha demostrado que los sueros que producen títulos relativamente altos pueden usarse para detectar reactivos de mala calidad, y que es eficaz la conservación de los sueros en un volumen igual de glicerina, almacenados a -20 °C

Diagrama de verificacion para evaluar reactivos de hemaglutinacion usados en el diagnostico de la enfermedad de Chagas / A control chart method for evaluating hemagglutination reagent used in Chagas' disease diagnosis

Se describe la tecnica del diagrama de verificacion, menos complicada y mas apta que la tecnica de analisis secuencial para evaluar lotes pequenos de reactivo. En este método se necesitan un reactivo de referencia, un conjunto de alrededor de 20 muestras de suero y un limite establecido de la varianza que, cuando es sobrepasado, determina el rechazo del lote puesto a prueba. La mitad de las muestras de suero deben ser reactivas con respecto al antigeno de Trypanosoma cruzi y la otra mitad deben ser no reactivas; los sueros reactivos tienen que ser utiles en el sentido que su respuesta ante un reactivo de buena calidad (como el de referencia) es distinta de la que manifiestan ante un mal reactivo. Con este procedimiento, el reactivo de referencia y el reactivo que se quiere evaluar se ponen a prueba con el conjunto de muestras de suero; se observan las diferencias entre los titulos obtenidos con los dos reactivos y se calcula la desviacion estandar promedio. Cuando esta es inferior al limite de verificacion previamente establecido, el lote de reactivo es aceptado; si supera el limite, se rechaza el lote. La experiencia del Laboratorio de Inmunologia del Instituto de Medicina Tropical de Sao Paulo, Brasil, ha demostrado que los sueros que producen titulos relativamente altos pueden usarse para detectar reactivos de mala calidad, y que es eficaz la conservacion de los sueros en un volumen igual de glicerina, almacenados a -20 °C

Almacenamiento a largo plazo de IgG e IgM en papel filtro para su uso en encuestas seroepidemiológicas de enfermedades parasitarias / Long-term storage of IgG and IgM on filter paper for use in parasitic disease seroepidemiology surveys

Para tratar de detrminar por cuánto tiempo se pueden almacenar los anticuerpos IgG e IgM en muestras de sangre conservadas en papel filtro, se obtuvieron muestras sanguíneas de 23 pacientes con toxoplasmosis. Se procedió a almacenar una porción de cada muestra en papel filtro a -20 °C y se dividió en tercios el suero restante; un tercio se dejó inalterado, un tercio se combinó con un volumen igual de glicerina y un tercio se liofilizó. Una vez hecho esto, todas las muestras se guardaron a -20 °C y se examinó parte de cada grupo para detectar anticuerpos IgG e IgM, practicando técnicas de inmunofluorescencia (IF) y de inmunodifusión radial (RID), después de un período de almacenamiento de 0, 3, 6, 9, 12 y 18 meses

Los resultados demostraron la dificultad de estimar cuál es la dilución de suero equivalente al eluato obtenido de las muestras almacenadas en papel filtro para fines de análisis. Además, dichos resultados indicaron que la IgG se deterioraba más rápidamente en las muestras almacenadas en papel filtro que en otras. Este deterioro relativamente más rápido de las muestras guardadas en papel filtro fue aun más marcado en el caso de la IgM... (AU)

Diagrama de verificación para evaluar reactivos de hemaglutinación usados en el diagnóstico de la enfermedad de Chagas / A control chart method for evaluating hemagglutination reagent used in Chagas' disease diagnosis

Se describe la técnica del diagrama de verificación, menos complicada y más apta que la técnica de análisis secuencial para evaluar lotes pequeños de reactivo

En este método se necesitan un reactivo de referencia, un conjunto de alrededor de 20 muestras de suero y un límite establecido de la varianza que, cuando es sobrepasado, determina el rechazo del lote puesto a prueba. La mitad de las muestras de suero deben ser reactivas con respecto al antígeno de Trypanosoma cruzi y la otra mitad deben ser no reactivas; los sueros reactivos tienen que ser útiles en el sentido que su respuesta ante un reactivo de buena calidad (como el de referencia) es distinta de la que manifiestan ante un mal reactivo

Con este procedimiento, el reactivo de referencia y el reactivo que se quiere evaluar se ponen a prueba con el conjunto de muestras de suero; se observan las diferencias entre los títulos obtenidos con los dos reactivos y se calcula la desviación estándar promedio. Cuando esta es inferior al límite de verificación previamente establecido, el lote de reactivo es aceptado; si supera el límite, se rechaza el lote. La experiencia del Laboratorio de Inmunología del Instituto de Medicina Tropical de Sao Paulo, Brasil, ha demostrado que los sueros que producen títulos relativamente altos pueden usarse para detectar reactivos de mala calidad, y que es eficaz la conservación de los sueros en un volumen igual de glicerina, almacenados a -20 ºC

Almacenamiento a largo plazo de IgG e IgM en papel filtro para su uso en encuestas seroepidemiológicas de enfermedades parasitarias / Long-term storage of IgG and IgM on filter paper for use in parasitic disease seroepidemiology surveys

Para tratar de detrminar por cuánto tiempo se pueden almacenar los anticuerpos IgG e IgM en muestras de sangre conservadas en papel filtro, se obtuvieron muestras sanguíneas de 23 pacientes con toxoplasmosis. Se procedió a almacenar una porción de cada muestra en papel filtro a -20 ºC y se dividió en tercios el suero restante; un tercio se dejó inalterado, un tercio se combinó con un volumen igual de glicerina y un tercio se liofilizó. Una vez hecho esto, todas las muestras se guardaron a -20 ºC y se examinó parte de cada grupo para detectar anticuerpos IgG e IgM, practicando técnicas de inmunofluorescencia (IF) y de inmunodifusión radial (RID), después de un período de almacenamiento de 0, 3, 6, 9, 12 y 18 meses

Los resultados demostraron la dificultad de estimar cuál es la dilución de suero equivalente al eluato obtenido de las muestras almacenadas en papel filtro para fines de análisis. Además, dichos resultados indicaron que la IgG se deterioraba más rápidamente en las muestras almacenadas en papel filtro que en otras. Este deterioro relativamente más rápido de las muestras guardadas en papel filtro fue aun más marcado en el caso de la IgM... (AU)