Severe Immune-Related Enteritis after In Utero Exposure to Pembrolizumab

Immune checkpoint blockade has become standard treatment for many types of cancer. Such therapy is indicated most often in patients with advanced or metastatic disease but has been increasingly used as adjuvant therapy in those with early-stage disease. Adverse events include immune-related organ inflammation resembling autoimmune diseases. We describe a case of severe immune-related gastroenterocolitis in a 4-month-old infant who presented with intractable diarrhea and failure to thrive after in utero exposure to pembrolizumab. Known causes of the symptoms were ruled out, and the diagnosis of pembrolizumab-induced immune-related gastroenterocolitis was supported by the results of histopathological assays, immunophenotyping, and analysis of the level of antibodies against programmed cell death protein 1 (PD-1). The infant's condition was successfully treated with prednisolone and infliximab.

Oral zinc and common childhood infections--An update

Zinc is an essential micronutrient important for growth and for normal function of the immune system. Many children in developing countries have inadequate zinc nutrition. Routine zinc supplementation reduces the risk of respiratory infections and diarrhea, the two leading causes of morbidity and mortality in young children worldwide. In childhood diarrhea oral zinc also reduces illness duration and risk of persistent episodes. Oral zinc is therefore recommended for the treatment of acute diarrhea in young children. The results from the studies that have measured the therapeutic effect of zinc on acute respiratory infections, however, are conflicting. Moreover, the results of therapeutic zinc for childhood malaria also are so far not promising.This paper gives a brief outline of the current evidence from clinical trials on therapeutic effect of oral zinc on childhood respiratory infections, pneumonia and malaria and also of new evidence of the effect on serious bacterial illness in young infants.

The importance of breastfeeding in rotaviral diarrhoeas

Globally, rotaviral vaccines in use today have contributed to the reduction of the incidence of rotaviral diarrhoeas. Despite the substantial protection conferred by the current vaccines against the rotaviral strains, it is only prudent to recognise that other protective factors, like breastfeeding, also provide some degree of protection against this disease. This article has attempted to review some important mechanisms of protection in breast milk against the rotaviruses and highlight the oft forgotten non-immunoglobulin fraction in breast milk as an additional tool of protection against rotavirus disease. The adaptive capacity of breast milk to environment is another compelling reason to continue breastfeeding as it can usefully complement and be significant in the use of many vaccines. Vital immunoprotective constituents in breast milk beneficially protect the infant by initiating and strengthening many immune responses and should be borne in mind as essential tools of defence even in an era where vaccines play a pivotal role in the combat against certain diseases. It is impressive that besides nutritive advantages, the suckling infant enjoys appreciable immunoprotection via exclusive breastfeeding.

Live Attenuated Human Rotavirus Vaccine, Rotarix™

Rotavirus infections are the leading cause of severe gastroenteritis in young children worldwide. Recently two new rotavirus vaccines have entered the world market. This review provides a summary of the rationale, development, and evaluation of one of these vaccines, Rotarix. Rotarix is a live oral rotavirus vaccine developed from a single protective human strain following multiple passages in tissue culture to attenuate the strain. The vaccine is administered as two oral doses at approximately 2 and 4 months of age. Large safety and efficacy trials have shown the vaccine is safe, not associated with intussusception, and effective against the most common circulating human serotypes. Efficacy against severe rotavirus gastroenteritis and hospitalization have ranged from 85 to 100 percent.

The Pentavalent Rotavirus Vaccine, RotaTeq™

Vaccination against rotavirus disease has been a global preventive health priority since rotaviruses were first discovered in the 1970s. The first licensed rotavirus vaccine, RRV-TV, was removed from the market shortly after licensure because of an unexpected serious adverse event, intussusception. A pentavalent rotavirus vaccine, PRV, is the second FDA-licensed rotavirus vaccine and does not signal the risk observed with RRV-TV. The properties and large safety study results of PRV are reviewed here.

Rotavirus vaccines: current prospects and future challenges

Rotavirus is the most common cause of severe diarrhoea in children worldwide and diarrhoeal deaths in children in developing countries. Accelerated development and introduction of rotavirus vaccines into global immunisation programmes has been a high priority for many international agencies, including WHO and the Global Alliance for Vaccines and Immunizations. Vaccines have been developed that could prevent the enormous morbidity and mortality from rotavirus and their effect should be measurable within 2-3 years. Two live oral rotavirus vaccines have been licensed in many countries; one is derived from an attenuated human strain of rotavirus and the other combines five bovine-human reassortant strains. Each vaccine has proven highly effective in preventing severe rotavirus diarrhoea in children and safe from the possible complication of intussusception. In developed countries, these vaccines could substantially reduce the number and associated costs of child hospitalisations and clinical visits for acute diarrhoea. In developing countries, they could reduce deaths from diarrhoea and improve child survival through programmes for childhood immunisations and diarrhoeal disease control. Although many scientific, programmatic, and financial challenges face the global use of rotavirus vaccines, these vaccines-and new candidates in the pipeline-hold promise to make an immediate and measurable effect to improve child health and survival from this common burden affecting all children.

Cytomegalovirus-associated protracted diarrhoea in an immunocompetent boy

AIM

Cytomegalvirus (CMV) gastroenteritis is rarely described in immunocompetent children. We describe here an immunocompetent 1-year-old boy with CMV-associated protracted diarrhoea and discuss the pathogenesis of CMV infection of the gastrointestinal tract.

METHODS

Immunohistochemical study was performed using a gastric and duodenal tissue of this patient. Furthermore, the detection of CMV-DNA in stool and urine samples was performed by polymerase chain reaction method.

RESULTS

CMV infection was proven by the detection of CMV-DNA in stool and urine samples and CMV-positive cells in the immunoperoxidase preparation from gastroduodenal biopsy. The biopsy specimens showed severe chronic active gastroduodenitis with numerous CD3+ T cells and CD68+ macrophages.

CONCLUSIONS

We speculated from these findings that CMV invasion of the mucosal layer induced an intense immune response characterised by massive infiltration of activated T-cells and macrophages in this patient. Although the pathogenesis of CMV-associated gastroenteritis in immunocompetent hosts remains generally unknown, immune mechanism may play some roles in generating the chronic inflammatory lesions.

Early consumption of human milk oligosaccharides is inversely related to subsequent risk of respiratory and enteric disease in infants

A pilot study tested the relationship between human milk oligosaccharide consumption, oligosaccharide content of feces, and subsequent disease in breastfed infants. Forty-nine (49) mother-infant pairs provided milk and fecal samples 2 weeks postpartum; infant health was assessed through 2, 6, 12, and 24 weeks. LNF-II (lacto-N-fucopentaose II), a major human milk oligosaccharide, was measured to represent levels of total oligosaccharides consumed in milk and remaining in feces. LNF-II levels in milk at 2 weeks postpartum were associated with fewer infant respiratory problems by 6 weeks (p = 0.010), as were LNF-II levels in infant feces (p = 0.003). LNF-II levels in milk at 2 weeks were also associated with fewer respiratory problems by 12 weeks (p = 0.038), and fewer enteric problems by 6 weeks (p = 0.004) and 12 weeks (p = 0.045). Thus, consumption of human milk oligosaccharides through breastfeeding, represented by LNF-II, was associated with less reported respiratory and gastrointestinal illness in infants.

IgM: mucosal response in acute diarrhoeal disease of infants

OBJECTIVE

Investigating the secretory immune response during the acute phase of diarrhoeal disease is hampered by difficulty in collecting suitable control specimens. This is particularly the case in infants, as they are the most severely affected by this disease. In this study we examined the mucosal immunoglobulin response during the acute phase of diarrhoeal disease in infants.

MATERIAL AND METHODS

The intestinal outputs of secretory immunoglobulins (IgA, IgM) and non-secretory proteins (IgG, albumin, A1AT, eosinophil cationic protein (ECP)) were measured in 14 African children with acute watery diarrhoea (less than 3 days). These data were compared with those of 38 controls from the same area who had undergone whole-gut lavage (WGL) (inducing non-pathogenic watery diarrhoea) in a previous study of intestinal immunity and inflammation. Intestinal secretion rates were measured by multiplying the concentration of the substances by the rate of administration of WGL fluid (equal to the output) or by the output of diarrhoea. Statistical comparison was made using the Mann-Whitney U-test.

RESULTS

IgA output in subjects with diarrhoea was 1.8-fold greater (80.7 versus 45.6 mg/kg/day, p=0.03), whereas IgM output was 10-fold greater (21 versus 2.1 mg/kg/day, p=0.0001). Albumin, A1AT and IgG were all also greater to varying degrees (2.5-6.8-fold). ECP was unchanged. Increases in the non-secretory proteins would suggest increased permeability of the gastrointestinal tract but transudation of serum was insufficient to explain the rise in immunoglobulin output.

CONCLUSIONS

The 10-fold increase in IgM secretion compared with a smaller relative increase in IgA suggests that this is the primary mucosal immune response in acute diarrhoeal disease.

Neonatal enteropathies: defining the causes of protracted diarrhea of infancy

The underlying causes of chronic diarrhea beginning early in life are increasingly well defined. Infectious and post-infectious enteropathies and food sensitive/allergic enteropathy account for the majority of cases. Recent attention has focused on characterizing defined entities, which cause protracted diarrhea in infants and young children. Disorders of intestinal ion transport usually present at birth following a pregnancy complicated by polyhydramnios. Intestinal mucosal biopsies show normal architect with intact villus-crypt axis. Neonatal enteropathies, by contrast, are characterized by blunting of the villi. These include microvillus inclusion disease, tufting enteropathy, autoimmune enteropathy and IPEX syndrome - and it is these conditions that are the subject of the current review.

Scientific rationale and benefits of nucleotide supplementation of infant formula

The present review examines the role of dietary nucleotides in infants, and the scientific rationale and benefits of nucleotide supplementation of infant formula. The immunoprotective benefits of human milk, the biology of human milk nucleotides, and the immunological and gastrointestinal effects of dietary nucleotides in animal studies and in vitro experiments are examined. Clinical studies are reviewed, especially those examining the efficacy of nucleotide-supplemented infant formula in enhancing immunity and reducing the risk of sepsis. The presence of human milk cells, and a variety of immunoactive and trophic components of human milk, can explain the reduced incidence of sepsis in breastfed term and preterm infants. Nucleotides, believed to play an immunomodulatory role, are found in lower concentrations in infant formula. Animal studies have shown that dietary nucleotides enhance a number of immune responses and the growth, differentiation and repair of the gut. Several clinical studies have reported beneficial effects of nucleotide supplementation on gut microflora, diarrhoea and immune function, and one study has reported better catch-up growth in term infants with severe intrauterine growth retardation. More basic research studying the metabolism of nucleotides in neonates is encouraged. Additional randomized controlled trials are necessary to demonstrate the clinical benefits of nucleotide supplementation of infant formula, as it cannot be presumed that nucleotides produce the same benefits for the infant as human milk. Studies are especially necessary in high-risk neonatal situations, such as extreme prematurity, significant suboptimal nutrient intake before and after birth, and recovery from gut injury.

Correlates of protection against rotavirus infection and disease

Repeated infections with the 'mucosal' pathogen rotavirus are common in children. Subsequent rotavirus infections usually cause milder symptoms than first-time infections. Therefore, although natural rotavirus infection attenuates the severity of subsequent infections, it does not prevent reinfection or mild disease. On the other hand, natural infection with 'systemic' viruses such as measles, mumps, rubella, or varicella often confers life-long protection against mild disease associated with reinfection. The degree to which differences in the pathogenesis of systemic and mucosal pathogens determines differences in the capacity of natural infection to induce life-long protective immunity will be discussed. This paradigm will be used to explore the immunological effector functions associated with protection against rotavirus challenge.

Immune status of infants fed soy-based formulas with or without added nucleotides for 1 year: part 1: vaccine responses, and morbidity

BACKGROUND

Immunologic development of soy-fed infants has not been extensively studied. Early studies of soy flour-based formulas showed decreased immunoglobulin production when soy protein intake was limited. However, there were no significant differences in rotavirus vaccine responses between breast-fed and soy protein isolate-based formula-fed infants. Nucleotides added to milk-based formula benefit infant immune status, but reports of the immunologic effects of adding nucleotides to soy-based formula are not available. This study evaluated immune status and morbidity of infants fed soy protein isolate formulas with and without added nucleotides for 1 year.

METHODS

Newborn, term infants enrolled in a masked 12-month feeding trial were assigned randomly to groups fed soy formula with or without added nucleotides (n = 94, n = 92). A nonrandomized human milk/formula cohort (n = 81) was concurrently enrolled. Recommended immunizations were administered at 2, 4, and 6 months. Immune status was determined from antibody responses to Haemophilus influenzae type b, tetanus, diphtheria, and poliovirus vaccines at 6, 7, and 12 months. Parents and physicians reported morbidity data.

RESULTS

All vaccine responses were within normal ranges. No response differences were observed between infants fed soy formula and those fed nucleotide-supplemented soy. However, antibody to H. influenzae type b at 7 and 12 months was higher in infants fed nucleotide-supplemented soy than in infants fed human milk/formula ( P = 0.007, P = 0.008, respectively). Human milk/formula-fed infants had higher poliovirus neutralizing antibody at 12 months than did soy-fed infants ( P = 0.016). Morbidity analyses showed that only physician-reported diarrhea was different among groups (groups fed human milk/formula had less diarrhea than did soy groups, P = 0.011).

CONCLUSIONS

Term infants fed soy protein isolate-based formulas have normal immune development as measured by antibody responses to childhood immunizations.

The mammary gland-infant intestine immunologic dyad

The human infant has a very small immune system and needs the support of the mother with the transplacentally arrived IgG antibodies to protect tissues with inflammatogenic and energy-consuming defense. The mucous membranes, where most infections occur, need support via the specialized secretory IgA antibodies and the many other mucosal defense mechanisms provided via the mother's milk. This defense is not inflammatogenic and energy-consuming. We learn about additional defense factors in the milk, like the anti-secretory factor, which seems to protect against diarrhoea. The milk contains numerous growth factors and cytokines, like leptin, which may promote the development of the intestine as well as the immune system. Results are appearing giving interesting evidence for enhanced protection against infection also after the termination of breastfeeding. This may occur via the priming of the infant's immune system after uptake of anti-idiotypic antibodies and lymphocytes from the milk. A breastfeeding motivation study in a large Pakistani village resulted in a 50% decrease of diarrhoea and infant mortality. Deep interviews with the mothers and the traditional birth attendants suggested that even better results may be obtained.

[Diarrhea caused by adenovirus and astrovirus in hospitalized immunodeficient patients]

BACKGROUND

Acute or chronic diarrheal illness are common complications in immunosuppressed patients such as human immunodeficiency virus (HIV)-infected, bone marrow or solid organ transplanted patients and those with leukaemias or other immune deficiency disorders. Due to the importance of recognizing the feasible etiologies of diarrhea in order to give the proper antimicrobial chemotherapy or to avoid a misdiagnosis of rejection in the case of transplanted patients, we have investigated adenovirus and astrovirus antigen in faeces from different immunosuppressed patients.

PATIENTS AND METHODS

Stool samples from 258 immunodeficient patients hospitalized at University Hospital Complex of Santiago of Compostela with acute or persistent diarrhea were collected between 1997-99 and assayed for astrovirus and adenovirus antigen. Viral antigen was detected by EIA. Other common enteric pathogens were also assayed.

RESULTS

Adenovirus antigen was positive in 5 cases (2%) and astrovirus antigen in 12 cases (5%). The most commonly patients infected was those with haematologic disorders and premature infants. HIV-infected patients were positive for astrovirus antigen in 3 cases. The majority of the cases were related with intestinal bacterial diseases or other circumstances, such as Clostridium difficile infection, both associated with prolonged antimicrobial therapy.

CONCLUSIONS

Astrovirus and adenovirus have to be considered as enteropathogens specially in immunocompromised hospitalized patients. An accurate diagnosis about diarrhea etiology is advisable in order to give a specific antimicrobial therapy, when it be necessary, or to avoid a misdiagnosis of rejection, in transplanted patients.

Immune response of Bangladeshi children with acute diarrhea who subsequently have persistent diarrhea

BACKGROUND

Because altered immune responses may be a risk factor for persistent diarrhea, various aspects of the immune response were examined to elucidate the underlying immune mechanisms that may be involved in the development of persistent diarrhea.

METHODS

Children (7-12 months of age) with watery diarrhea for 6 to 8 days from the Dhaka Hospital of the International Centre for Diarrheal Disease Research, Bangladesh (ICDDR,B), were enrolled. Children were classified as having acute diarrhea (AD) or persistent diarrhea (PD) if diarrhea resolved within 14 days or persisted for more than 14 days, respectively. Uninfected control children (n = 13), from the Nutrition Follow-Up Unit of ICDDR,B were also enrolled. Of the 123 children with diarrhea who were enrolled, 85 had AD and 38 had PD. Comparisons were performed for clinical features, nutritional status (weight for age, plasma transferrin, and serum albumin levels), and immune responses: neutrophil function; peripheral blood mononuclear cell function, delayed-type hypersensitivity (DTH) responses, plasma levels of immunoglobulins, tumor necrosis factor-alpha, and interferon-gamma. Univariate analyses were conducted to assess differences among the three groups of children and between children with AD and PD. Logistic regression was performed to determine risk factors for PD.

RESULTS

There were no differences in clinical features and nutritional status among the groups of children studied. More children in whom PD developed had a negative DTH response to tuberculin than those with AD (P = 0.021). Also, a negative DTH response to tuberculin was a significant risk factor for PD (odds ratio [OR] = 3.8, 95% confidence interval [CI] = 1.5-9.9).

CONCLUSIONS

Children with acute diarrhea with a negative DTH response to tuberculin are more likely to have development of persistent diarrhea.

Rotavirus serotypes: classification and importance in epidemiology, immunity, and vaccine development

The development and implementation of safe and effective vaccines to prevent the enormous health burden of rotavirus-associated disease is a global public health goal. Human rotaviruses, the major aetiological agents of severe infantile diarrhoea worldwide, display surprisingly diverse and complex serotypic specificities. Ten VP7 serotypes and 7 VP4 serotypes have so far been detected. An increasing number of observations, obtained from analyses of (i) natural rotavirus infections in infants and young children, (ii) experimental rotavirus infections in laboratory animals, and (iii) extensive rotavirus vaccine field trials performed in different populations of various parts of the world, appears to support the concept that serotype-specific antibodies to rotaviruses play an important role in protection against rotavirus-associated illnesses. Thus, the first licensed rotavirus vaccine (RRV-based quadrivalent vaccine) was designed to cover the epidemiologically important VP7 serotype 1, 2, 3, and 4.

[Anti-rotavirus vaccinations]

Rotavirus is the most common cause of severe acute diarrhea, responsible for 30 to 40 deaths of children each year in France. In order to decrease both mortality and morbidity, vaccines have been designed first from attenuated bovine strains, then from monovalent simian strains, and more recently from reassortant rhesus strains. The live tetravalent human-rhesus reassortant vaccine (RRT-TV) has been shown to be protective in the United States, Finland, and Venezuela despite different environments, in prospective double-blind studies. This vaccine, as the natural infection, decreases by 50% the risk of acute rotavirus diarrhea and by 70 to 100% the risk of severe diarrhea with dehydration. At the present time, its cost limits its use to developed countries. It was put on the market in the United States in October 1998. The challenge is now to make it available in developing countries.

Rotaviruses detected by reverse transcription polymerase chain reaction in acute gastroenteritis during a trial of rhesus-human reassortant rotavirus tetravalent vaccine: implications for vaccine efficacy analysis

BACKGROUND

Rotaviruses are routinely diagnosed by detection of rotavirus antigen in stools using an enzyme immunoassay (EIA). A sensitive method, like reverse transcription polymerase chain reaction (RT-PCR), may reveal more rotaviruses, but the clinical significance of such findings is not well established.

OBJECTIVES

To study whether RT-PCR can detect more episodes of rotavirus-associated gastroenteritis than EIA and to determine how rotavirus RT-PCR findings might change efficacy analysis of a rotavirus vaccine trial, in which the outcome measure was rotavirus gastroenteritis diagnosis with EIA.

STUDY DESIGN

We applied RT-PCR for detection of rotaviruses in gastroenteritis episodes encountered in an efficacy trial of rhesus-human reassortant rotavirus tetravalent (RRV-TV) vaccine, in a total of 2398 infants. During a follow-up, covering two rotavirus epidemic seasons, 256 cases of rotavirus associated gastroenteritis were detected by EIA; 226 were in the primary efficacy analysis period that included children who had received three doses of vaccine or placebo.

RESULTS

With RT-PCR, 84 (33%) more cases of rotavirus gastroenteritis were diagnosed than with EIA, 65 of these were in the primary efficacy analysis period. Clinically, cases of rotavirus gastroenteritis diagnosed by RT-PCR were much milder (median severity score 6 on a 20-point scale) than those diagnosed by EIA (median score 11), P < 0.0001. RT-PCR revealed proportionally more G2 and G4 rotaviruses than EIA. G1 rotaviruses detected by RT-PCR were almost equally divided between RRV-TV (25) vaccine and placebo (28) groups, whereas an apparent vaccine protective effect was seen in the distribution of G2 (one in the RRV-TV and eight in the placebo group) and G4 rotaviruses (six in the RRV-TV and 14 in the placebo group).

CONCLUSION

RT-PCR is a useful tool in the diagnosis of rotavirus gastroenteritis, particularly for cases associated with other than the epidemiologically dominant G-type. Application of RT-PCR contributes to the overall appraisal of performance of rotavirus vaccine.

Age-related prevalence of Shigella and Salmonella antibodies and their association with diarrhoeal diseases in Peruvian children

Shigella and Salmonella antibodies in relation to diarrhoea were studied in a cohort of 413 children between 2 and 27 months of age in peri-urban Lima, Peru. Blood samples were obtained at 2, 3 and 12 months of age. Antibody titres against lipopolysaccharide from Shigella flexneri serotype Y, Shigella dysenteriae serotype 1, Shigella sonnei, Salmonella serogroups AO, BO, DO, and Shigella Ipa and Salmonella typhi Vi antigens were measured by enzyme immunoassay. IgG titres against S. flexneri and Shigella Ipa were higher at 2 than at 3 or 12 months of age (p=0.001), while the changes in IgG titres against S. dysenteriae, S. sonnei and Salmonella were not pronounced. IgA and IgM titres against S. flexneri, Shigella Ipa, S. dysenteriae, S. sonnei and Salmonella were significantly higher at 12 than at 2 or 3 months of age (p=0.001). Stool samples were obtained from children in 64% of all diarrhoeal episodes. Shigella spp. were isolated from 20% of the children during the first 2 y of life and Salmonella in 3%. Most isolates were from children at 13-24 months of age (78%). IgG antibodies at 12 months of age did not protect against shigellosis during the second year of life.

Extended excretion of rotavirus after severe diarrhoea in young children

BACKGROUND

Rotaviruses are the major cause of severe childhood diarrhoea. Knowledge of the natural history of infection, including duration of intestinal virus shedding, is important in the understanding of transmission, sources of infection, and immune responses.

METHODS

We carried out a study of rotavirus excretion in 37 children admitted to hospital with severe rotavirus diarrhoea. Sequential faecal specimens were collected from each child during 100 days of surveillance, and screened for rotavirus by EIA and by amplification of genome double-stranded RNA by reverse-transcription PCR. IgA coproantibody was estimated by EIA.

FINDINGS

Duration of rotavirus excretion ranged from 4 to 57 days after onset of diarrhoea. Excretion ceased within 10 days in 16 (43%) children, and within 20 days in 26 (70%) children. Extended excretion was detected for 25-57 days in the remaining 11 (30%) children owing mainly to continued excretion of the primary infecting strain. Extended excretion was significantly associated with antirotavirus IgA coproantibody boosts during 100 days of surveillance (p=0.001, log-rank test), and with recurrence of mild diarrhoea symptoms during convalescence (p=0.006, Fisher's exact test).

INTERPRETATION

Severe rotavirus disease in young children may be followed by extended excretion of rotavirus. The risk of transmission to others may be greater than previously believed. Extended excretion could also explain some cases of the postgastroenteritis syndrome.

Humoral immune and clinical responses to food antigens following acute diarrhoea in children

OBJECTIVE

To investigate the effect of acute watery diarrhoea in children upon humoral immune responses to food antigens and the subsequent development of food allergy.

METHODOLOGY

Serum antibodies to cows' milk, beta-lactoglobulin, alpha-lactalbumin, bovine serum albumin and ovalbumin were measured in 30 children with acute diarrhoea in the acute phase and 1 month after recovery. The children were followed for 1 year to assess the development of food allergy.

RESULTS

IgG antibeta-lactoglobulin titres for the study group increased 1 month after recovery compared to the titres during the acute phase (P = 0.02). Antibody concentration for the other antigens studied did not rise. Four children developed positive IgE antibodies to one or more of the allergens after the diarrhoeal episode, although the titres were very low. None showed evidence of allergy to cows' milk or egg during the year-long follow-up.

CONCLUSIONS

Acute diarrhoea in children resulted in increased production of IgG antibody to beta-lactoglobulin and had a priming effect for development of positive IgE antibody to cows' milk. Clinical food allergy was not observed in any of the children during the year-long follow-up.

Role of human-milk lactadherin in protection against symptomatic rotavirus infection

BACKGROUND

Human milk contains a 46 kDa mucin-associated glycoprotein, lactadherin, which binds specifically to rotavirus and inhibits its replication. This study tested the hypothesis that lactadherin protects against symptoms of rotavirus infection.

METHODS

200 infants in Mexico City were recruited at birth and monitored by regular stool EIA for rotavirus, serology, and recording of feeding and stool patterns. Milk samples were obtained from the mothers weekly until 4 weeks post partum then monthly. The sample taken immediately before an infant's episode of rotavirus infection was assayed for lactadherin, butyrophilin, mucin, and secretory IgA. An infection was defined as symptomatic if diarrhoea occurred in the 5 days before or after detection of the virus.

FINDINGS

31 infants developed rotavirus infection; 15 were symptomatic and 16 had no symptoms. The median concentration of lactadherin in the milk samples (obtained 4-41 days [median 13] before the infection) was 48.4 (range 5.6-180) microg/mL in the asymptomatic group and 29-2 (6.2-103-4) microg/mL in the symptomatic group. Although these medians did not differ significantly, in logistic regression analysis adjusted for age at infection and secretory IgA concentration there was a significant difference between the groups (p=0O01). No association between symptom status and concentrations of butyrophilin, mucin, or secretory IgA was found.

INTERPRETATION

Protection against rotavirus by human milk is associated with the glycoprotein lactadherin. This association is independent of products of the secretory immune system.

Value of faecal leucocyte count as an indicator of invasiveness in mucoid diarrhoea

Importance of faecal leucocyte count as an indicator of invasiveness in mucoid diarrhoea was studied. A total of 290 faecal specimen, 170 from mucoid diarrhoea and 120 from watery diarrhoea were examined for faecal leucocyte count under high power field (hpf) from rural children below four years of age during the period from November 1992 to October 1995. Faecal leucocyte count > 10/hpf was noted in 45.9% of mucoid diarrhoea as against 19.2% of watery diarrhoea (p < 0.0001) samples. From faecal samples with > 10 faecal leucocyte count, invasive pathogens could be recovered in 19 (24.5%) to none of 23 patients with watery diarrhoea (p < 0.006 Fisher exact test). This sample test appears to be of value as an indicator of invasiveness in mucoid diarrhoea in the absence of culture facility.

The molecular basis of intractable diarrhoea of infancy

The intractable diarrhoeas of infancy present very major problems of clinical management. However, the conceptual importance of these conditions lies in the information that they may provide about normal small-intestinal function in humans: among such infants will be found the human equivalents of the 'knock-out' mice, in which targeted gene disruption allows sometimes unexpected insight into the regulation of intestinal function. The challenge posed by the intractable diarrhoeal syndromes, of working backwards from an apparently common phenotype to probably multiple genotypes, is, however, immense. Very few of these conditions have been described at the genetic level, although the molecular basis of pathogenesis has been better explored in recent years. The two major groups of intractable diarrhoea are due to (1) primary epithelial abnormalities (which usually present within the first few days of life) and (2) immunologically mediated (which generally present after the first few weeks). The high prevalence of autoimmune enteropathy among infantile autoimmune disease, in contrast to adult autoimmunity, is intriguing and may reflect constitutive abnormality of extrathymic lymphocyte maturation. The use of potent immunosuppressive drugs and increasing expertise with parenteral nutrition are improving the outlook of these previously fatal conditions. Viewed globally, however, the pressing problem is to treat effectively the millions of infants who die from severe persistent diarrhoea and wasting, which would certainly not be considered intractable in wealthy countries.

Human colostrum IgA antibodies reacting to enteropathogenic Escherichia coli antigens and their persistence in the faeces of a breastfed infant

IgA antibodies reacting to enteropathogenic Escherichia coli (EPEC) antigens in human colostrum and their role in the inhibition of EPEC adherence to HEp-2 cells were studied. Colostrum IgA was isolated with a Sepharose anti-IgA column. IgA-depleted colostrum lost its inhibitory effect on EPEC adhesion, while the IgA-enriched eluate was a potent adherence inhibitor. The same eluate showed a significant loss of inhibitory activity after absorption with an EPEC strain showing localised adherence (LA+), but no alteration after absorption with an LA- strain. No bands were observed in Western blot analysis with LA+ absorbed eluate and with a crude extract of the EPEC strain, but the eluate absorbed with LA- showed a strong recognition of a 94-kDa band, a molecular weight equivalent to that of intimin. Colostrum antibodies reacting to non-protein antigens were not detected by Western blot analysis. The persistence of anti-EPEC IgA in the gastrointestinal tract was shown by the strong reactivity to the 94-kDa band in Western blot analysis of one mother's colostrum and her infant's faeces. These data confirm the role of colostrum antibodies in protecting the neonate against infections due to EPEC.

Congenital intractable diarrhea of infancy in Iraqi Jews

We report on five patients who presented with intractable diarrhea starting during the first days of life. The patients belonged to four families of Iraqi Jewish origin. Autosomal recessive inheritance is suggested by parental consanguinity in three families and recurrence in another sib in one family. The patients were all born after uneventful pregnancy and labor, with birth weight in the normal range. There were no dysmorphic features. Three patients were breast fed. Diarrhea started between the first and eighth day of life. Diarrhea was of the secretory type. No pathogen was cultured from the stool. Jejunal biopsies performed on all patients ranged from normal to severe partial villous atrophy. The patients received different drug regimens with no beneficial effect and all are dependent on TPN. These findings and the common ethnic origin of the patients suggest that these patients have the same syndrome of congenital intractable diarrhea. No similar cases are known in other ethnic groups in Israel, suggesting a possibility of high gene frequency among the Jews of Iraqi origin.

Rotavirus infection in infants as protection against subsequent infections

BACKGROUND

Rotavirus is the leading cause of severe diarrhea in infants. To provide a base line for assessing the efficacy of rotavirus vaccines, we evaluated the protection that is conferred by natural rotavirus infection.

METHODS

We monitored 200 Mexican infants from birth to two years of age by weekly home visits and stool collections. A physician assessed the severity of any episodes of diarrhea and collected additional stool specimens for testing by enzyme immunoassay and typing of strains. Serum collected during the first week of life and every four months thereafter was tested for antirotavirus IgA and IgG.

RESULTS

A total of 316 rotavirus infections were detected on the basis of the fecal excretion of virus (56 percent) or a serologic response (77 percent), of which 52 percent were first and 48 percent repeated infections. Children with one, two, or three previous infections had progressively lower risks of both subsequent rotavirus infection (adjusted relative risk, 0.62, 0.40, and 0.34, respectively) and diarrhea (adjusted relative risk, 0.23, 0.17, and 0.08) than children who had no previous infections. No child had moderate-to-severe diarrhea after two infections, whether symptomatic or asymptomatic. Subsequent infections were significantly less severe than first infections (P=0.024), and second infections were more likely to be caused by another G type (P=0.054).

CONCLUSION

In infants, natural rotavirus infection confers protection against subsequent infection. This protection increases with each new infection and reduces the severity of the diarrhea.

Oral IgA-IgG treatment of chronic non-specific diarrhoea in infants and children

The effect of orally administered immunoglobulin (IgAbulin) on chronic non-specific diarrhoea of infancy was studied in seven children, median age 26 (21-36) months and duration of diarrhoea 32 (18-84) weeks. Routine laboratory tests for malabsorption and small bowel biopsies were taken in all children before and after 3 weeks of IgAbulin treatment. The biopsy specimens were analysed with regard to histopathology, electronmicroscopy, immunohistochemistry and microbiology. The number of stools decreased from a median of 4.0 (3.0-5.0) to 1.5 (1.0 3.5) (p < 0.05) stools per day over the study period.

[Clinical and experimental study on wenchangning oral liquor in treating infantile autumn diarrhea]

Gold-Dampness Syndrome of Infantile Autumn diarrhea treated with Wenchangning Oral Liquor was observed clinically. There were 238 cases in the treated group, the cure rate was 81.9%. In comparing with control group (32 cases in Huoxiang Zhengqi Liquid group, 50 cases in gentamycin group), there were highly significant difference between treated and control groups in the cure rate, markedly effective rate, total effective rate, time for stopping diarrhea and for disappearing of clinical symptoms, P < 0.01 and < 0.001. Clinical practice and animal experiments revealed that the drug had no toxic and side-effects. The possible therapeutic mechanisms were; (1) Anti-Rotavirus, anti-diarrhea; (2) Promote the recovery of intestinal digestive and absorptive function; (3) Enhance the immune function of the body; (4) Inhibit the motility of intestinal tract, Wenchangning Oral Liquor is rapid in action, conveniant in administration and safe, conforming to the criteria for the preventing and treating diarrhea of World Health Organization.

Concomitant rotavirus serotypes 1 and 4 infections in a diarrhoeic child from Belém, Brazil

Concomitant serotypes 1 and 4 infections were detected in a 15-month old female child with community-acquired diarrhoea which lasted 7 days and coursed with moderate dehydration. The evidence for dual rotavirus infection was offered by the following findings: a) enzyme-linked immunosorbent assay (ELISA) positive reactions to both 1 and 4 serotypes; and b) extra-migrating bands at electrophoresis of RNA in polyacrylamide gel (PAGE). These results suggest that children living under poor sanitation conditions are heavily exposed to rotavirus infections; in addition, the co-circulation of different serotypes in the same setting sustains the current concept that a rotavirus vaccine should be multivalent, in order to protect children against the four epidemiologically important rotavirus G serotypes.

X-linked immune dysregulation, neonatal insulin dependent diabetes, and intractable diarrhoea

Four related male infants presented with neonatal diabetes mellitus, immune dysregulation with extremely high concentrations of immunoglobulin E, and intractable diarrhoea. They were all from one family, and all of them died. As far as is known this X-linked recessive disorder has not been described before. It is suggested that this is a new immunodeficiency in which type 2 T helper responses predominate.

Antibody response to measles-mumps-rubella vaccine of children with mild illness at the time of vaccination

OBJECTIVE

To examine the response to measles-mumps-rubella (MMR) vaccine among children with and without mild illness.

DESIGN

Prospective cohort.

PARTICIPANTS

A total of 386 children aged 15 to 23 months.

MAIN OUTCOME MEASURES

Seroconversion rates to measles, mumps, and rubella in ill and well children.

SETTING

Six public health immunization clinics in two counties in the greater metropolitan Atlanta, Ga, area from February 1992 to April 1993.

RESULTS

Acute upper respiratory tract infection, otitis media, and diarrhea were observed in 128 (33%), 41 (11%), and 13 (3%) of the children (groups are not mutually exclusive); 157 children had one of these mild illnesses and 229 were well. Overall seroconversion rates were 98% for measles, 83% for mumps, and 98% for rubella antigens. Measles seroconversion rates for ill children compared with well children, respectively, were as follows: upper respiratory tract infection, 99% vs 97%; mild fever, 98% vs 97%; otitis media, 98% vs 98%; diarrhea, 100% vs 98%; and any mild illness, 99% vs 97%. Estimates of the magnitude of antibody response to measles, mumps, and rubella antigens were the same for children with and without mild illness. There was no association of mild illness with increased rates and severity of adverse events reported in the 2 weeks after vaccination.

CONCLUSIONS

Vaccinating children who present with mild illnesses with MMR vaccine is a safe and efficacious practice. These results support recommendations of the Advisory Committee on Immunization Practices and the American Academy of Pediatrics.

[Autoimmune enteropathy]

Autoimmune enteropathy was initially described in young male infants presenting as severe secretory diarrhea. The disease is characterized by an inflammatory reaction which may involve several organs (bowel, pancreas, thyroid, kidneys, liver) with the presence of various circulating antibodies. The disease may also be observed in older children and in females with usually less bowel involvement. In view of the autoimmune basis of the disease, treatment requires immunosuppressive agents in addition to parenteral nutrition.

[Rotavirus infection: clinical characteristics and time of elimination of the rotavirus antigen in the feces]

BACKGROUND

A prospective study was performed during three years with 76 children hospitalized with the diagnose of rotaviral gastroenteritis. The aim of our study were to evaluate the clinical features of the rotaviral gastroenteritis, the excretion time of rotavirus in stools and the nosocomial rotavirus infection.

METHODS

The detection of the rotaviral antigen in stool was performed using a rapid test based on latex aglutination (Rotalex). For the determination of the excretion time of rotavirus in stools the test was performed daily in 69 children until the results was negative. Furthermore, a clinical study of the patients was carried out.

RESULTS

In 39 cases (51.3%) the gastroenteritis was acquired in the community and 37 cases (48.7%) were nosocomially acquired. The most frequent clinical presentation was an acute diarrhea (96%) with vomiting (63.2%) and fever (63.2%). Only three patients did not have diarrhea. The mean duration of diarrhea was between 3-4 days with a highest duration of 10 days. Most of the patients (58%) had an excretion time of rotaviral antigen lower or equal than 3 days, with an extreme value of 14 days.

CONCLUSIONS

In our study rotaviral infection occurred mainly in the cooler winter months and in children younger than 6 months of age. A high nosocomial infection level (48.7%) was detected. Vomiting often preceded the onset of diarrhea and fever. The excretion time of rotaviral antigen was independent of the clinical course.

T-lymphocyte subsets and prolonged diarrhea in young children from Guinea-Bissau

In a community-based prospective study of 380 children conducted between 1987 and 1990, the rate of diarrhea was significantly associated with percentage of CD8 T-lymphocytes and the CD4:CD8 ratio. After adjustment for age and previous diarrhea, the relative incidence of diarrhea with a duration of > or = 7 days was 2.10 (95% confidence interval (CI) 1.15-3.85) in children with 20-29.9% CD8 T-cells and 3.41 (95% CI 1.29-9.01) in children with > or = 30% CD8 T-cells (in comparison with children who had less than 20% CD8 cells) (p for trend = 0.004). There was a nonsignificant tendency for rates of diarrhea of > or = 7 days to decrease according to increasing proportions of CD4 cells (p = 0.194). The authors found no significant association between T-cell subsets and diarrhea which resolved within 6 days. The association between the incidence of prolonged diarrhea and T-cell subset proportions could not be explained as a confounding effect of low weight, breastfeeding, or previous infection with measles or Cryptosporidium. However, other prior infections or micronutrient deficiencies may explain the findings, and these host factors may be significant targets in intervention against diarrheal diseases.

Hyperimmune cow colostrum reduces diarrhoea due to rotavirus: a double-blind, controlled clinical trial

The therapeutic efficacy of hyperimmune bovine colostrum (HBC) from cows immunized with four serotypes of human rotavirus was evaluated in a double-blind, randomized trial in 75 boys, aged 6-24 months, infected with rotavirus diarrhoea. The treatment group received 100 ml of HBC three times a day for 3 consecutive days, while the controls received the same amount of bovine colostrum from significantly shorter duration of diarrhoea than the controls (median 56 versus 72 h (p<0.001); confidence interval of median difference (CI) 8-32 h). Total stool output (g/kg) between admission and cessation of diarrhoea was reduced by 29% in the HBC-treated group compared with controls (median 205 versus 290 g (p=0.04); CI = 1-154 g). In 50% of the children in the study group, diarrhoea stopped by 48 h, whereas 100% of the controls were still suffering from diarrhoea. No untoward effects were noted in either group. Colostrum from cows immunized with rotavirus antigen is clinically effective in reducing the duration and severity of childhood diarrhoea due to rotavirus.

[Antigenic types of circulating rotavirus in children with acute diarrhea in Santiago de Chile]

Protective immunity against rotavirus infection is directed against antigenic epitopes on the outer capsid proteins VP7 and VP4. The aim of this study was to characterize the VP7 and VP4 antigenic types circulating in different hospital areas of Santiago, Chile, over different time periods. Between April 1993 and April 1994 a total of 1206 stool samples were obtained from children consulting for acute no bloody diarrhea in 5 hospitals representative of the 5 major health areas of Santiago. In addition, 256 rotavirus positive samples, obtained from children with acute diarrhea consulting in the north health area of Santiago between 1985-1987 were studied. All samples were processed for rotavirus by an ELISA and all rotavirus positive samples were VP7 typed (types G1-G4) by a monoclonal antibody based ELISA. 50 rotavirus positive samples were selected for VP4 typing by PCR (types P1-P4). A total of 782 rotavirus positive samples were obtained of which 618 (79%) were typable for one specific VP7 type. VP7 type G1 represented 63% of the rotavirus positive samples and predominated in all areas evaluated throughout the entire period of observation. VP7 type G2 represented 13% of rotavirus samples, following G1 in predominance. G2 types decreased progressively in all areas in both study periods. G4 types were detected mainly during 1985-1987, and G3 types have so far not been detected. Preliminary analysis of VP4 types suggests that P1 types are predominant and closely associated with VP7 G1 type. These results are relevant for the adoption of appropriate preventive strategies for rotavirus infection, specifically aimed to the development of effective vaccines.

Breastfeeding and immunity to intestinal infections

The purpose of this study was to compare immune response in breast and non breastfed children presenting with diarrhoea at Paediatric Observation Ward, Kenyatta National Hospital (KNH-POW) and Maternal and Child Health Clinic, Pumwani Maternity Hospital (PMH-MCH). Blood and stool samples were collected from the first four consecutive children aged 5 years and below per day, presenting with or without diarrhoea from January to December, 1992. The stools were tested for total IgA by single radial immunodiffusion (SRID) and specific IgA by enzyme linked immunosorbent assay (ELISA). Peripheral blood CD4 and CD8 enumeration was done by flow cytometry. Stools were cultured for bacteria on selective media while ova and cysts of parasites were identified by wet preparation microscopy. A total of 457 children were enrolled into the study, 69.6% of whom presented with diarrhoea. Breastfed children tended to have a shorter duration of diarrhoea than either mixed fed or bottle fed (8.3 vs 9.8 vs 11.2 days, p = 0.2). In general, E. coli were more commonly isolated from breastfed than mixed fed or bottle fed (56.7% vs 43.9% vs 28.9%, p = 0.004) while intestinal parasites were mostly in bottle fed than mixed or breastfed children (28.8% vs 8.2 vs 0.8, p < 0.004). However, when children with diarrhoea were considered, E. coli was more frequently isolated from bottle fed children who presented with diarrhoea than without (26.7% vs 7.7%, p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)