Passive acquisition of anti-Staphylococcus aureus antibodies by newborns via transplacental transfer and breastfeeding, regardless of maternal colonization

OBJECTIVE: To investigate the transmission of anti-Staphylococcus aureus (Sa) IgG, IgG1 and IgG2 via placental transfer and the transfer of IgA via the colostrum according to maternal Sa carrier status at delivery. METHODS: We evaluated anti-Sa IgG, IgG1 and IgG2 in maternal and cord sera and IgA in colostrum from a case (n=49, Sa+) and a control group (n=98, Sa-). RESULTS: Of the 250 parturients analyzed for this study, 49 were nasally colonized with S. aureus (prevalence of 19.6%). Ninety-eight non-colonized subjects were selected for the control group. The anti-Sa IgG, IgG1 and IgG2 levels and the IgG avidity indexes in the maternal and cord sera did not differ between the groups, with a low transfer ratio of anti-Sa IgG to the newborns in both groups. The anti-Sa IgG2 titers were significantly higher than the IgG1 titers in the maternal and cord sera. Inversely, the transfer ratios were higher for anti-Sa IgG1 compared with IgG2; however, no differences between the groups were detected. The Sa-specific IgA levels and avidity indexes in the colostrum were equivalent between groups. CONCLUSIONS: Maternal Sa nasal colonization at delivery is not associated with higher antibody levels in the mother or newborns. The high titers of anti-Sa IgG2 found in the cord serum indicate a greater reactivity with non-protein antigens, which may further contribute to the susceptibility to staphylococcal infections at birth. The presence of IgA in the colostrum with avidity to S. aureus reinforces the importance of breastfeeding shortly after birth.

Inmunología perinatal / Perinatal immunology

Se ha considerado que el útero gestante es un lugar inmunológicamente privilegiado, donde el feto es protegido del rechazo por el sistema inmune materno, mediante un amplio repertorio de estrategias de evasión que contribuye a la sobrevivencia del feto. La gestación en sí misma constituye un acontecimiento de equilibrio inmunológico y la tolerancia inmunológica permite la progresión del embarazo, donde participan una secuencia sincronizada de eventos que se inicia desde la concepción y fertilización para dar lugar a la implantación y progresa hasta alcanzar un embarazo a término. El sistema inmune es la principal barrera que poseemos para protegernos de las infecciones. Durante la vida intrauterina, el feto está protegido por la madre de las agresiones externas, por lo que no necesita que su sistema inmunológico sea operativo, sin embargo, al nacer, recibe una avalancha de elementos extraños, por lo que necesitará disponer de cierta protección, así como una preparación para ejecutar las defensas necesarias para su protección inmunológica. La inmunidad sérica durante la vida fetal queda limitada a la transferencia a través de la placenta de IgG materna, a pesar de que el feto tiene la facultad de sintetizar inmunoglobulinas desde las primeras etapas de la gestación. Al nacimiento, el niño tiene su sistema inmunológico completo, aunque inmaduro, pero es capaz de responder a los estímulos antigénicos. Tiene múltiples anormalidades en el desarrollo de su sistema inmune, que involucran a los anticuerpos/inmunoglobulinas, complemento y granulocitos pudiendo contribuir a la alta incidencia de sus infecciones. El recién nacido carece de memoria inmunológica debido a que, en condiciones normales, el feto está exento de estímulos producidos por antígenos extraños. Dicha memoria se va adquiriendo a medida que entra en contacto con los diferentes antígenos. Se obtendrá cierta protección a las infecciones entéricas gracias a las IgA que aporta la lactancia materna. La exposición prenatal y postnatal a productos microbianos ambientales que pueden activar la inmunidad innata, puede acelerar el proceso de maduración del sistema inmune.(AU)

It has been considered the pregnant women`s womb as an immunological exceptional place, where fetus is protected against been rejected because of maternal immune system by means of a wide groups of evasive strategies that help in its survival. Pregnancy itself is an immunological equilibrium state and the immunological tolerance allow the progression of this event, where participate a synchronized sequence of biological events started from conception and fertilization to allow the implantation, and progress until to reach the pregnancy end. The immune system is our main barrier against infections. During intrauterine life fetus is protected by the mother against external aggressions, therefore he don`t need an operative immune system, nevertheless, at birth the new organisms receive an avalanche of strange elements needing some kind of protection as well as a preparation to carry out the necessary defense for his immunological protection. Serum immunity during fetal life is limited to the transference of maternal IgG through placenta, despite fetus capability to synthesize immunoglobulins from first stages of gestation. At birth the babe has a complete immunological system although immature but capable to respond to antigenic stimulus. He has multiples abnormalities in the immune system development that take account antibodies/immunoglobulin, complement and granulocytes contributing to his high incidence of infections. Newborn lack immunological memory because in normal conditions fetus is not stimulated by odd antigens. This memory is acquired through the contact with different antigens. It will be obtained some protection against enteric infections because IgA from maternal lactation. The prenatal and postnatal exposition to environmental microbial products that activate the innate immunity can accelerate the immune system maturing process.(AU)

Perfil das amostras do sistema nervoso central de bovinos com síndrome neurológica e diagnóstico da raiva bovina no serviço de defesa sanitária de Minas Gerais, 2003-2010 / Profile of central nervous system samples from cattle with neurological syndrome and diagnosis of bovine rabies by the service of sanitary defense of Minas Gerais, 2003-2010

As enfermidades do sistema nervoso central (SNC) são frequentemente relatadas em bovinos no Brasil. Apesar de Minas Gerais ter o segundo maior rebanho bovino do país, há escassez de informações referentes às doenças neurológicas que acometem esses animais. O Laboratório de Saúde Animal do Instituto Mineiro de Agropecuária (LSA/IMA) é o responsável pelo diagnóstico das enfermidades neurológicas dos animais de produção no Estado, com ênfase para a raiva e as encefalopatias espongiformes transmissíveis. Foi realizado um estudo retrospectivo dos dados referentes às amostras de SNC de bovinos com síndrome neurológica avaliadas pelo LSA/IMA de janeiro/2003 a junho/2010, com o objetivo de determinar o perfil das amostras encaminhadas para análise no serviço de defesa sanitária animal, com ênfase no diagnóstico da raiva bovina. Foram consideradas características do animal (sexo, idade, raça e tipo de morte) e da amostra (método de conservação e responsável pela coleta), sendo nas positivas para raiva, avaliada sua composição, assim como as alterações histopatológicas encontradas. Os dados relacionados à frequência de positividade nas diferentes categorias foram submetidos à análise pelo Teste Exato de Fisher. Durante o período avaliado, foram analisadas 3.731 amostras de bovinos com doença neurológica, havendo predomínio de fêmeas e mestiços, o que reflete a composição do rebanho do Estado. O método de conservação foi o principal problema encontrado, sendo apenas 25,89% das amostras encaminhadas em gelo e formol a 10%. Verificou-se uma diminuição gradativa no envio de material para análise. Quanto a raiva bovina diagnosticada no Estado, foram avaliadas 3.703 amostras pela imunofluorescência direta (IFD) e prova biológica (PB), com 41,58% de positividade, sendo dessas 282 submetidas a histopatologia. A frequência de positividade foi influenciada pela raça, idade e tipo de morte do animal. A composição da amostra alterou significativamente o resultado das análises, havendo maior frequência de positividade naquelas compostas por três ou mais fragmentos de SNC, tanto na IFD/PB, quanto na histopatologia. O bulbo, fragmento de eleição para o diagnóstico da EEB, tem sido erroneamente enviado refrigerado e não em formol a 10%. Cerebelo, tálamo, tronco encefálico e medula apresentaram maior frequência de corpúsculos de Negri que cérebro e gânglio trigeminal. O infiltrado inflamatório não supurado foi menos frequente no cérebro, que nos demais fragmentos avaliados. Conclui-se que as amostras de bovinos com síndrome neurológica enviadas ao serviço de defesa sanitária animal de Minas Gerais apresentam características distintas, sendo o método de conservação o principal problema encontrado. Além disso, a raiva bovina diagnosticada na população estudada é influenciada pelas características do animal e da amostra, sendo indicado o envio de diferentes fragmentos do SNC para análise, conservados adequadamente, o que contribui para um diagnóstico mais preciso.(AU)

Diseases of the central nervous system (CNS) are often reported in cattle in Brazil. Although the State of Minas Gerais has the second largest cattle herd in the country, there is little information from this state concerning neurological diseases that affect cattle. The Laboratório de Saúde Animal of the Instituto Mineiro de Agropecuária (LSA/IMA) is in charge of the diagnosis of neurological diseases of livestock in the State, with emphasis on rabies and transmissible spongiform encephalopathies. A retrospective study was conducted on data from cattle with neurologic diseases evaluated by the LSA/IMA from January/2003 to June/2010, aiming to determine the profile of CNS samples sent for analysis, with emphasis on the diagnosis of bovine rabies. Issues related to the animal (sex, age, breed and type of death) as well as to the sample (method of conservation, person in charge the collection, and region of the CNS sampled) were evaluated. Data on frequency of rabies positive samples were analyzed by Fisher's exact test. During the period studied, 3,731 samples from cattle with neurological signs were analyzed, with a predominance of females and crossbred cattle. The method of preservation was the main problem encountered with only 25.89% of samples sent both refrigerated and fixed in 10% formaldehyde. There was a gradual decrease in submission of samples during the course of this study. All 3,703 samples were evaluated by direct fluorescent antibody test (DFA) and biological test (BT) for rabies, 41.58% being positivity for rabies, and 282 of those samples being subjected to histopathology examination. The frequency of positivity was influenced by breed, age, and type of death. Composition of the sample significantly influenced the results, with higher frequency of positivity in samples containing three or more CNS fragments by DFA, BT, or histopathology. The medulla, which is the fragment of choice for diagnosis of BSE, has often been mistakenly submitted under refrigeration, but not in 10% formalin. Cerebellum, thalamus, brain stem, and spinal cord had higher frequency of Negri bodies than the cerebral cortex and trigeminal ganglia. The nonsuppurative inflammatory infiltrate was less frequent in the cerebral cortex than in other CNS fragments. In conclusion, CNS samples from cattle with neurological syndrome sent to the animal health protection service of Minas Gerais are heterogeneous, and the preservation method was the major problem hindering and adequate diagnosis. In addition, diagnosis of rabies was influenced by parameters of the animal as well as the CNS sample. Submission of properly preserved fragments from various segments of the CNS contributes to a more accurate diagnosis of rabies in cattle.(AU)

Seroconversion of hepatitis B vaccine in infants related to the mother's serostatus in a community of São José dos Campos, state of São Paulo, Brazil

PURPOSE: To detect seroconversion of hepatitis B vaccine and antibody waning 3 years after vaccination in children immunized according to the World Health Organization schedule and its relationship to the mother's serostatus during pregnancy. METHODS: A serological study was carried out in São José dos Campos. Blood samples from pregnant women were taken for hepatitis B marker serology. To evaluate seroconversion in infants born to these women, serology was performed 1 month after they were vaccinated with recombinant vaccine. Another group of children was evaluated 3 years after being immunized. RESULTS: Among 224 pregnant women, 0.9 percent were positive for hepatitis B surface antigen, 8.0 percent for antibodies to the surface antigen, and 4.5 percent for antibodies to the virus core. Seroconversion among 174 infants was as follows: absent in 18 children (10.35 percent), low level in 15 (8.62 percent), intermediate level in 26 (14.94 percent), and a high level (good response) in 115 (66.09 percent). Antibody positivity after 3 years was as follows: absent in 8 children (7.92 percent), low level in 51 (50.5 percent), intermediate level in 20 (19.8 percent), and high level in 22 (21.78 percent). Considering the age that the vaccine was administered, a significant proportion of non-seroconverters was found among children who had received the complete 3-dose schedule before 9 months (P = 0.023). Another factor that significantly contributed to the lack of seroconversion was the presence of any serological marker for hepatitis B during pregnancy (P = 0.044). CONCLUSIONS: Data gathered in this work show that the immunization schedule for hepatitis B in low or moderate prevalence areas should be revised in order to optimize seroconversion.

OBJETIVO: Determinar a soroconversão vacinal da hepatite B em crianças no primeiro ano de vida e sua relação com a soropositividade das mães e avaliar a concentração de anticorpos 3 anos após a vacinação. MÉTODOS: Estudo sorológico, realizado na cidade de São José dos Campos com amostras de sangue coletadas de gestantes para testar marcadores de Hepatite B. Para avaliar a soroconversão em crianças nascidas dessas mulheres, realizou-se sorologia mês após a última dose de vacina. Em outro grupo de crianças, imunizadas há 3 anos, foi feita a mesma sorologia. RESULTADOS: Entre 224 gestantes, 0,9 por cento foram positivas para o antígeno de superfície, 8,0 por cento para anticorpos contra este antígeno e 4,5 por cento para anticorpos contra o "core" viral. A soroconversão de 174 crianças, um mês após a última dose da vacina, foi ausente em 18 crianças (10,35 por cento), baixa em 15 (8,62 por cento), intermediária em 26 (14,94 por cento), e houve boa resposta em 115 (66.09 por cento). A soropositividade de 101 crianças vacinadas há 3 anos, foi ausente em 8 (7,92 por cento), baixa em 51 (50,5 por cento), intermediária em 20 (19,8 por cento), e alta concentração de anticorpos em 22 (21,78 por cento). Considerando a idade da vacinação, encontrou-se uma proporção significante de crianças soronegativas entre vacinadas antes dos 9 meses (p=0,023). Contribuiu significativamente para a baixa soroconversão a positividade de qualquer marcador sorológico durante a gravidez (p=0,044). CONCLUSÃO: Os dados reunidos neste trabalho mostram que o calendário vacinal para a Hepatite B em regiões de baixa ou moderada prevalência poderia ser revisado para otimizar a soroconversão.

Respuesta inmune en neonatos no infectados nacidos de madres infectadas por Trypanosoma cruzi / Immune responses of non-infected neonates of mothers infected with Trypanosoma cruzi

We have investigated if maternal T. cruzi infection could induce in utero innate and/or adaptive immune responses in uninfected neonates by measuring specific IgM and IgA antibodies in cord blood plasma, and by performing phenotypic and functional studies of umbilical cord blood cells of their newborns (M+B- group). We detected T. cruzi-specific IgM and IgA antibodies in M+B- cord blood, indicating they had mounted in utero a strong B cell response, although they are not infected. On the other hand, circulating T cells of such uninfected neonates displayed a low level of activation, as seen bya slightly increased expression of the activation markers CD45RO on CD4+ T cells and HLA-DR on CD8+ T cells, although the proportion of CD4+ and CD8+ T cells was unmodified as compared to newborns from uninfected mothers (MB- group). This activation did not give rise to a proliferative response upon stimulation by T. cruzi antigens in vitro. However, M+B- cells produced low levels of lymphokines (IFN-gamma and IL-13) upon mitogenic stimulation, which was not the case of M-B- newborn cells. Beside this, M+B- blood cells produced higher levels of inflammatory cytokines (IL-1b, IL-6, TNF-alpha) than M-B- cells when stimulated with the T. cruzi lysate or LPS, suggesting the over-activation of the innate response in M+B- newborns. Monocytes participated in such inflammatory response since M+B- purified cord blood monocytes produced higher levels of TNF- when incubated with LPS or a T. cruzi lysate than M-B- cells. Altogether, these results show that, even in the absence of congenital infection, maternal T. cruzi infection triggers in utero both adaptive and innate immune responses in their babies. This indicates that parasite circulating antigens have been transferred from mothers to their fetuses.

Características do lactente hospitalizado com infecção do aparelho respiratório inferior por vírus sincicial respiratório: tipos e genótipos do vírus e anticorpos séricos específicos / Characteristics of infants hospitalized with lower respiratory tract infection due to respiratory syncytial virus: types and genotypes of the virus and specific serum antibodies

As doenças do aparelho respiratório inferior (DARI) são responsáveis por altos índices de morbi-mortalidade em crianças em todo o mundo. O principal agente causador de DARI em lactentes é o vírus sincicial respiratório (VSR), que acomete, principalmente os lactentes no primeiro ano de vida. O perfil dos tipos e genotipos de VSR causadores de DARI e o papel dos anticorpos séricos do lactente ainda estão indefinidos. Este conhecimento é importante para o desenvolvimento de medidas terapêuticas e profiláticas eficazes.Throughout the world, lower respiratory tract infection (LRTI) is responsible for high mortality rates among children. The main etiological agent of LRTI in infants is respiratory syncytial virus (RSV) that mainly involves infants in the first year of life. The profile of the types and genotypes of RSV that cause LRTI and the role of the infant's serum antibodies have yet to be fully clarified. This knowledge is important for the development of effective therapeutic and prophylactic measures...

Transplacental transfer of measles antibody in Delhi.

OBJECTIVE: To find out the patterns of and the factors, if any, affecting the transplacental transfer of measles antibody. DESIGN: Comparison of measles antibody titres in mothers with titres in cord blood samples. METHODS: Maternal and cord blood samples from 174 full-term pregnant women of middle socio-economic status were tested for hemagglutination inhibition (HI) antibody against measles in Delhi during October 1993 to January 1995. None of the mothers had been immunized against measles. RESULTS: Antibody were undetectable in both maternal and cord samples in only 4 (2.3%) pairs. Mean maternal titre was found to be 2.94 Log2. Transplacental concentration and dilution were respectively observed in 34% and 26% of the samples. Cord titres were more often higher than the maternal values only if the maternal values were low. Overall, cord/maternal ratio of mean titre (Log2) was found to be 1.06. Although the age of the mother and parity had had no significant bearing on the transplacental transfer of measles antibody, cord titres were significantly more often higher than the maternal values as the birth weight increased (Chi-square for linear trend = 5.4; p = 0.02). CONCLUSIONS: The study failed to show appreciable concentration of measles antibodies across the placenta.

Estudio del perfil inmunologico en la mujer gestante a termino y en el recien nacido / Study of the inmunologic profile in the pregnant women and the new-born

Con el objeto de determinar las modificaciones del sistema inmunologico en la mujer gestante y en el recien nacido, por efecto del parto se analizaron los valores de globulos blancos, inmunoglobinas y complemento en ambas, se estudiaron 52 mujeres gestantes con embarazo de 36 a 41 semanas sin enfermedad antes ni durante el embarazo en trabajo de parto, que consultan al Instituto "Natalio Aramayo" asi como tambien a los recien nacidos de parto eutosico y distosico. Se tomaron muestras sanguineas de sangre periferica (madre) y de cordon umbilicar (recien nacido) con y sin anticoagulante para dosificacion de inmunoglobulinas y recuento de leucocitos. El recuento de leucocitos en la gestante fue de 11.369 /uL mm3 con un minimo de 5.500 y un maximo de 24.600 (SD 6300/uL) mientras que en el recien nacido fue de 11.030 mm3 (SD 3600/mm3). El recuento diferencial fue: polimorfonucleares en un 86.46 por ciento y linfocitos en un 13.53 por ciento. En el recien nacido: PMN en un 76,61 por ciento y linfocitos en un 23.07 por ciento. Los valores obtenidos para las inmunoglobulinas fueron: en la madre IgG 1.434 mg/dL; IgM 215.38 mg/dL; IgA 244,46 mg/dL; C3 154 mg/dL y C4 30.7 mg/dl. En el recien nacido IgG 1514 mg/dL; IgA 2,46 mg/dL; IgM 11.46 mg/dL; C3 92.3 mg/dL y C4 21.1 mg/dL. Se pudo constatar la leucocitosis de la gestante a predominio de PMN. Por los valores obtenidos se concluye que el parto distosico condiciona el aumento de IgG, tanto en niños como en la madre (P<0.05), esta relacion se invierte en la madre (p<0.05). Se debera realizar un nuevo estudio valorando el sistema inmune en la etapa de post parto mediato y tardio.

Transferência materna da imunidade antituberculose / Transference of the anti-tuberculosis immunity from the mother to the newborn

Foi realizado estudo de coote retrospectivo, com o objetivo de avaliar a ocorrência da aquisiçÝo da imunidade passiva antituberculose, por via transplacentária ou através do leite materno, utilizando métodos "in vivo" (Teste Tuberculínico e BCG-teste). A classificaçÝo dos grupos, de acordo com a exposiçÝo, foi baseada na resposta ao teste de Mantoux, observada em 101 puérperas, cujo parto ocorreu no período de junho de 1993 e agosto de 1994, na Maternidade Prof§ Monteiro Morais (Recife-PE). Considerou-se como grupo de expostos (n=26), os recém-nascidos filhos de mÝes com forte reatividade ao PPD(>10mm) e, como nÝo expostos (n=65), os filhos de mÝes nÝo reatoras(<5mm). A aquisiçÝo passiva da imunidade celular foi avaliada através do BCG-teste e teste de Montoux, realizados nos recém-nascidos. Nenhum deles apresentou reatividade ao PPD-RT23. tanto na dose de 2UT como na de 5UT, o que evidência a ineficácia deste método no período neonatal. Apenas os resultados dos BCG-testes foram considerados, onde os nódulos > 5mm foram classificados como positivos e os nódulos <5mm, negativos. Observou-se uma associaçÝo significativa entre a positividade ao BCG-teste dos recém-nascidos e o teste tuberculínico materno (p=0,0362). O coeficiente de incidência encontrado no grupo de expostos foi de 65,4 por cento e, no grupo de nÝo exportos, de 38,5 por cento, fornecendo um Risco Relativo de 1,70. Com base nos resultados obtidos, conclui-se que houve transferência de experiência imunológica da mÝe para o recém-nascido. A aquisiçÝo passiva da imunidade anti-tuberculose, pode interferir na eficácia da vacina BCG aplicada no período neonatal, o que recomenda estudos posteriores

Exclusive breastfeeding: protective efficacy.

A longitudinal study of feeding practices of and morbidity in 537 infants was undertaken. Feeding practices were assessed at monthly follow-up visits. All infants were initially exclusively breastfed but their percentage dropped to 59.8% and 35.3% at the end of 3 months and 6 months respectively. Exclusively breastfed babies were three-times less likely to fall sick than artificially fed babies. Exclusive breastfeeding was also associated with significantly lowered rate of serious illnesses as shown by fewer rate of hospitalisation (0.52/100 children months vs 4.5/100 children months). Premature introduction of supplementary feeding diluted the protective effects of breastmilk.

Trypanosoma cruzi infection in the opossum Didelphis marsupialis: absence of neonatal transmission and protection by maternal antibodies in experimental infections

The high rate of natural Trypanosoma cruzi infection found in opossums does not always correlate with appreciable densities of local triatomid populations. One alternative method which might bypass the invertebrate vector is direct transmission from mother to offspring. This possibility was investigated in five T. cruzi infected females and their litters (24 young). The influence of maternal antibodies transferred via lactation, on the course of experimental infection, was also examined. Our results show that neonatal transmission is probably not responsible for the high rate of natural T. cruzi infection among opossums. In addition antibodies of maternal origin confer a partial protection to the young. This was demonstrated by the finding of a double prepatency period and 4,5 fold lower levels of circulating parasites, in experimentally infected pouch young from infected as compared to control uninfected mothes. On the other hand, the duration of patent parasitemia was twice as long as that observed in the control group

Anticuerpos antitiroideos en hipotiroidismo congénito / Antithyroid antibodies in congenital hypothyroidism

El papel que los anticuerpos antitiroideos maternos pueden desempeñar en la etiopatogenia del hipotiroidismo congénito por atireosis es discutible. En este estudio se midieron los niveles séricos de antivuerpos antitiroideos en 12 pacientes hipotiroideos y en sus madres, con la finalidad de detectar la posible asociación entre enfermedad tiroidea autoinmune materna y displasia tiroidea fetal. En dos pacientes hubo anticuerpos antitiroglobulina, lo que apoya la teoría de la existencia de un proceso inmunológico contra la tiroides fetal en las primeras ocho semanas de festación, pero no descarta la existencia y/o coexistencia de otros factores etiopatogénicos

Transferencia in vitro de inmunidad a PPD con extracto dializable de leucocitos de calostro humano / In vitro immunity transference of PPD with human dialysable colostral leukocyte extract

Se pretende demostrar la transferencia de hipersensibilidad a PPD en un modelo in vitro con extracto dializable de leucocitos de calostro de madres PPD- y PPD+ (EDLC PPD- Y PPD-), a través de la medición de la actividad del factor inhibidor de la migración de leucocitos (LIF) de sangre de cordón de recién nacidos de madre PPD+. En los resultados se observa que el EDLC PPD+ incubado con leucocitos de recién nacidos de madres PPD- tuvieron inhibición de la migración de los leucocitos, comprados con la migración de los leucocitos incubados con EDLC PPD-; lo que sugiere que en el modelo in vitro se transfiere hipersensibilidad a PPD con el EDLC.

Maternal fetal immunological relationship particularly mycobacterial immunity.

Thirty-nine paired maternal and cord blood from normal full term deliveries were tested for lymphocyte function by proliferative response to mitogens-Phytohemagglutinin-P (PHA) and Poke week mitogens (PWM). Monocyte function was assessed by the ability of the monocytes to release hydrogen peroxide (H2O2) in response to standard stimulus (PMA). Mycobacterial immunity was assessed by lymphocyte proliferative response to purified proteins derivative (PPD) and IgM and IgG antibody response to H37Rv and 5 atypical mycobacteria. Lymphocyte functions were significantly lower in cord blood (PHA 20.6, PWM 21.2) as compared with maternal blood (PHA 65.8, PWM 37.8). The capacity of fetal monocytes to release H2O2 was comparable to maternal monocytes. The mean proliferative response of fetal lymphocytes to tubercular protein (PPD) was 0.67 as compared (P less than 0.01) to maternal lymphocytes (3.79). Nearly 86% of the cord blood did not show any response to PPD. None of the cord blood showed IgM antibody response to H37Rv nor to any of the range of 5 atypical mycobacteria though maternal IgM and IgG response was present. There was only passive transfer of IgG antibody from mother to fetus. Hence, though this is a highly endemic area for atypical mycobacteria and M. tuberculosis, there was apparently no transplacental transfer of antigen in normal sensitized mothers.

Prevalence of placentally transmitted antibodies for measles in infants 3 to 11 months old in an urban slum community.

Upto 35% of infants aged between 6 and 11 months are infected with measles in India with its associated high morbidity and mortality. The objective of the study is to know the waning pattern of placentally transmitted antibodies (PTA) for measles so that the age at which children are likely to become susceptible to measles infection could be identified. A cross-sectional serological survey of children aged 3 to 11 months in one of the Integrated Child Development Service (ICDS) area in Madras city slums was done. Venous blood from 376 children was collected and was tested for Hemagglutination Inhibition (HI) antibodies by standard microtitration technique. Titre greater than or equal to 1:8 has been considered as protective. The proportion of children with immune level and the Geometric Mean Titre (GMT), declined to the least by 5 months which denotes that most of the infants become susceptible to measles infection from as early as 5 months of age. There is no significant difference in the waning pattern between different age groups, sex and nutritional status. A community study for effectiveness of measles vaccine at 6-8 months of age is needed to know the feasibility of immunization earlier than 9 months of age.