[Hemangiomas in infancy]

Hemangiomas are the most common tumors of childhood. Although most hemangiomas remain innocuous, a significant minority may be associated with important complications. The morphology and location of a hemangioma of infancy are critically important factors in determining potential risk for complications. Ongoing research on pathogenesis will provide new opportunities for interventional and preventive therapies.

How much protein is safe?

BACKGROUND

Since breastfeeding and human milk seem to prevent, while high dietary proteins in the first 2 y of life seem to promote, later overweight, questions have been raised on the safe levels of proteins in the early years. How much protein (as a percentage of total calorie intake) is safe?

METHODS

Revision of available data on the protein content of human milk, protein intake in the first 2 y of life and their association with body mass development.

RESULTS

We should move from the figure of 7-8% in the 4-month exclusively breastfed infants up to the maximum acceptable levels of 14% in 12-24-month-old infants. When protein supply represents less than 6% and energy is limited, fully breastfed infants are likely to enter a status of negative nutrient balance. Over the limit of 14% energy from proteins in the 6-24 months period, some mechanisms may begin to operate, leading young children towards an early adiposity rebound and overweight development, beyond any genetic predisposition. Preliminary data seem to indicate a causal role for whole cow's milk proteins.

CONCLUSION

We suggest maintaining breastfeeding as long as possible, and, in case human milk is insufficient, to introduce infant formulas, appropriate for age, up to 18-24 months, in order to keep protein intakes in the safe range of 8-12% within a diet adequate in energy and balanced as far as macronutrients.

Efficacy of ACE-inhibitor therapy on renal disease in glycogen storage disease type 1: a multicentre retrospective study

BACKGROUND

The efficacy of ACE-inhibitors in decreasing microalbuminuria and proteinuria has been reported in a few patients with glycogen storage disease type 1 (GSD1); however, no case-control study has ever been published.

AIM

The aim of the current study was to evaluate the efficacy of ACE-inhibitors in reducing glomerular hyperfiltration, microalbuminuria and proteinuria, and in delaying the progression of renal damage.

PATIENTS AND METHODS

Ninety-five patients (median age at the time of the study: 14.5 years) were enrolled from nine Italian referral centres for metabolic diseases. A retrospective study of a 10-year follow-up was conducted in order to compare the evolution of these parameters in treated patients with those who were not treated with ACE-inhibitors.

RESULTS

A significant and progressive decrease of glomerular filtration rate was observed in treated patients vs. those who were not treated with ACE-inhibitors (P < 0.05). No difference was observed for microalbuminuria and proteinuria between the two groups of patients. Moreover, the ACE-inhibitors significantly delayed the progression from glomerular hyperfiltration to microalbuminuria, but not that from microalbuminuria to proteinuria.

CONCLUSIONS

The results of the present study underline the importance of a strict follow-up of renal function in GSD1 patients. The detection of glomerular hyperfiltration suggests precocious initiation of ACE-inhibitor treatment to delay the progression of renal damage. A randomized prospective study is needed to establish for certain the real effectiveness of this treatment in GSD1 patients.

[Bilateral periventricular nodular heterotopia in a couple mother-infant]

Bilateral periventricular nodular heterotopia in a couple mother-infant. Bilateral periventricular nodular heterotopia (BPNH) is a malformation of neuronal migration, recently recognized X-linked. We report a case of BPNH associated with mega-cisterna magna diagnosed by ultrasound imaging at 27 weeks' gestation and confirmed by MR at 11 days of life. Similar findings in the mother's MR underlines the recurrency of this malformation in the same family.

Abdominal ultrasonography in inheredited diseases of carbohydrate metabolism

PURPOSE

To determine the usefulness of abdominal sonography in inherited diseases of carbohydrate metabolism.

MATERIALS AND METHODS

Thirty patients (age range, 4 months to 27 years) with glycogen storage diseases, galactosemia, disorders of fructose metabolism were studied with sonography. Echogenicity of the liver, sonographic dimensions of liver, kidneys and spleen were evaluated. Plasma blood parameters (ALT, AST, total cholesterol, triglycerides) were determined.

RESULTS

Liver was enlarged in 21/22 patients (95.4%) with glycogen storage diseases, in both subjects with disorders of fructose metabolism, and in 2/6 patients (33.3%) with galactosemia. Hepatic echogenicity was increased in 20/22 patients (90.9%) with glycogen storage diseases, and in the subject with hereditary fructose intolerance. Patients with galactosemia did not show increased liver echogenicity. Both kidneys were enlarged in 8/17 patients (47.0%) with glycogen storage disease type I. Subjects with increased hepatic echogenicity exhibited higher plasma concentrations of any blood parameter than the others with normal echogenicity (p<0.05).

CONCLUSIONS

Sonography can be useful in identification of inherited diseases of carbohydrate metabolism even if further examinations are necessary for an ultimate diagnosis.

Immunogenicity and tolerability of a trivalent virosomal influenza vaccine in a cohort of HIV-infected children

Twenty-three children infected with the human immunodeficiency virus (HIV) were vaccinated with a trivalent inactivated virosomal influenza vaccine. Serum haemagglutinin inhibition antibody titres were determined for the three viral strains at the time of vaccination and 1 month later. CD4 cell counts and HIV viral loads were measured to evaluate the effect of vaccination on HIV status. Adverse reactions were monitored during the first hour following vaccination by an investigator and then on a continuous basis by the parents. Seroconversion rates against the three viral strains A/H3N2, A/H1N1 and B were 73.9%, 56.5% and 52.2%, respectively. Geometric mean antibody titres increased after 1 month compared with baseline values (A/H3N2: 70.9 versus 13.5; A/H1N1: 24.7 versus 5.8; B: 34.4 versus 9.1). No significant changes were observed in either HIV viral load or CD4 cell count following vaccination. Vaccination was well tolerated with only a few mild, transient symptoms.

Body mass index rebound and overweight at 8 years of age in hyperphenylalaninaemic children

AIM

To evaluate whether the age at body mass index (BMI) rebound may be associated with overweight at age 8 y in hyperphenylalaninaemic (HPA) children.

METHODS

A longitudinal observational study including 97 HPA children born 1984-1993 and detected by the National Neonatal Screening programme. Children were followed up at the same institution and evaluated for dietary intakes and anthropometrical parameters from diagnosis up to the age of 8 y. Outcome measure was overweight at age 8 y, defined according to the International Obesity Task Force. The age at BMI rebound, BMI before and at rebound were considered as potential determinants. Familial overweight, breastfeeding and macronutrients intake at age 1 y were considered as confounders.

RESULTS

Mean (95% confidence interval [CI]) age at BMI rebound was 5.0 (4.7-5.3) y. At the age of 8 y, 24.7% (95% CI 16.3-33.1%) of children was overweight. Children overweight at the age of 8 y exhibited earlier BMI rebound than non-overweight children (mean difference [95% CI] -2.1 [-2.8 to - 1.4] y) and higher BMI from the age of 1 y (mean difference [95% CI] 1.2 [0.9-2.5] kg/ m2) onward. Overweight was more likely in children with, rather than without, parental overweight (41.0% vs 19.8%). After adjustment for confounders, logistic analysis showed that earlier BMI rebound (odds ratio [OR] 2.4, 95% CI 1.2-4.8) and BMI at age I y (OR 2.3, 95%CI 1.1-4.98) were independently associated with overweight at the age of 8 y.

CONCLUSION

Within the population of this study, overweight at age 8 y was positively associated with early BMI rebound and BMI at age 1 y.

[Immunological development in asymptomatic HIV infected children]

In HIV infected children, CD45+CD4+ T lymph. reconstitution has been related to efficient thymopoiesis. Because human thymus undergoes spontaneous involution at a relatively young age, institution of antiretroviral therapy early in the course of infection has been recommended. 12 HIV vertically infected children aged 4-8 years were investigated T-cell subsets for four years. 7 children were naive for therapy (group NT); 5 experienced nucleoside analogues only (group T). CD45RA+ and CD45RO+ CD4+ values were compared to predicted values of healthy children. The two groups showed similar clinical and immunological baseline characteristics (CDC class N-A). Mean VL at t0 was 4.26 log10 (SD 0.71) in gr. NT and 4.01 log10 (SD 0.57) in gr. T; median CD4 T lymph values were 27% in gr. NT and 23.5% in gr. T. Median CD45RA+ values were 62.8% in gr. NT and 71.3% in gr. T. No differences in VL, CD4+ T lymph., CD45RA+, CD45RO+ were found in between groups or within each group at each time evaluation. Median CD45RA+ values were not different from predicted values of healthy children. None of the children changed CDC class during the study period. Although the number of subjects was small, our study evidenced the possibility of a normal immunological development in HIV-1 vertically infected asymptomatic children naive for HAART during the first decade, even in the presence of significant viremia.

Polychlorinated biphenyls in colostral milk and visual function at 12 months of life

BACKGROUND AND AIMS

Environmental contaminants such as persistent organic chlorines and heavy metals, which are supplied to the foetus by transplacental transfer and to breastfed infants by the milk, may impair cognitive functions. Long-chain polyunsaturated fatty acids, which are known to enhance development during foetal life and early infancy, may counteract the toxic effect of environmental contaminants. In this study, we have investigated whether polychlorinated biphenyls (PCBs) impair early development of vision, and whether such impairment can be modulated by essential long-chain polyunsaturated fatty acids.

MATERIAL

Healthy term infants born in Milan and its surroundings, and who were exclusively breastfed for at least 4 mo, were prospectively examined up to the age of 12 mo.

METHODS

Samples from colostrums, the first 2 d after delivery, and of mature breast-milk after 1 and 3 mo were collected. The samples were analyzed for PCB 105, 118, 138, 153, 156 and 180 and for DDT and DDE. In all infants, the plasma levels of the long-chain polyunsaturated fatty acids (LC-PUFAs), C18:2 n-6, C18:3 n-3, C20:4 n-6, C20:5 n-3 and C22:6 n-3 were analysed within the first three postnatal days. The PCB levels in colostral milk, as well as of LC-PUFAs in plasma, were considered to mirror perinatal supply. Visual function was evaluated by P100 with latency evoked potentials (VEPs) at 12 mo of age. Statistical analysis was based on simple and partial correlation coefficients (p < 0.05).

RESULTS

On bivariate analysis, wave latency VEP at 15 min was significantly related to the colostral levels of DDT, DDE and all examined PCBs except PCB 105 (with correlation coefficient r = 0.401 to 0.618), whereas P100 wave latency VEP at 60 min was related to DDT (r = 0.513) and PCB 180 (r = 0.504). Infant plasma levels of C22:6 n-3 were inversely associated with P100 wave latency at 60 min (r = -0.418) and at 1Hz-2J (r = -0.466). After controlling for C22:6 n-3, the partial correlation coefficient of P100 wave latency VEP at 15 min to the colostral level of PCB 180 was 0.403 (p = 0.07).

CONCLUSION

Within the population of this study, a weak relation was found between impaired visual function at 12 mo of age of healthy infants and the levels of PCBs, DDT and DDE in colostral milk. The effect of impairment was no longer evident after controlling for the plasma level of LC-PUFAs as found in the infant a few days after birth.

Early protein intakes and adiposity: reloaded or downloaded?

It has been hypothesized that feeding human milk through the first year of life may have a protective effect towards a later adiposity development, in contrast with formula feeding. The low protein content of human milk has been hypothesized as a plausible biological hypothesis. Regardless, it is often underscored that feeding human milk is associated with a higher rate of weight gain in the first two months of life.

CONCLUSION

In our opinion, it seems that the protective effect of human milk, if any, on adiposity development is far more complex, and tightly bound to the peculiarity of human milk composition and breastfeeding practice.

Feeding practices of infants through the first year of life in Italy

AIM

To investigate infant feeding practices through the first year of life in Italy, and to identify factors associated with the duration of breastfeeding and early introduction of solid foods.

METHODS

Structured phone interviews on feeding practices were conducted with 2450 Italian-speaking mothers randomly selected among women who delivered a healthy-term singleton infant in November 1999 in Italy. Interviews were performed 30 d after delivery and when the infants were aged 3, 6, 9 and 12 mo. Type of breastfeeding was classified according to the WHO criteria.

RESULTS

Breastfeeding started in 91.1% of infants. At the age of 6 and 12 mo, respectively, 46.8% and 11.8% of the infants was still breastfed, 68.4% and 27.7% received formula, and 18.3% and 65.2% were given cow's milk. Solids were introduced at the mean age of 4.3 mo (range 1.6-6.5 mo). Introduction of solids occurred before age 3 and 4 mo in 5.6% and 34.2% of infants, respectively. The first solids introduced were fruit (73.1%) and cereals (63.9%). The main factors (negatively) associated with the duration of breastfeeding were pacifier use (p < 0.0001), early introduction of formula (p < 0.0001), lower mother's age (p < 0.01) and early introduction of solids (p = 0.05). Factors (negatively) associated with the introduction of solids foods before the age of 3 mo were mother not having breastfed (p < 0.01), early introduction of formula (p < 0.01), lower infant bodyweight at the age of 1 mo (p = 0.05) and mother smoking (p = 0.05).

CONCLUSION

The duration of breastfeeding in Italy is still inadequate, as well as compliance with international recommendations for timing of introduction of complementary foods. National guidelines, public messages and educational campaigns should be promoted in Italy.

Infants vertically infected with hepatitis C: a long term longitudinal follow-up

HCV vertically acquired infection is asymptomatic and characterized by a high chronic infection rate; only 9% of HCV infected children shows spontaneous remission. As far as a mild course of the disease has been observed during childhood, we hypothesize that any eventual treatment intervention could be postpone until adolescent age.

Tolerance to a rice hydrolysate formula in children allergic to cow's milk and soy

BACKGROUND

Even hydrolysed cow's milk formulae may retain residual allergens and there are few nutritional options for children with cow's milk allergy (CMA) who also react to soy.

OBJECTIVE

To assess clinical tolerance to a rice-based hydrolysate in children with such a clinical presentation.

PATIENTS AND METHODS

Eighteen children (six girls and 12 boys; median age 5 years; range 1-9 years) with CMA, who developed clinical reactions to a soy-based formula after 2-18 months' treatment, were recruited between January 1998 and June 1999. Clinical evaluation was by skin prick test (SPT) with cow's milk, casein, lactalbumin, soy and rice allergen extracts, fresh cow's milk, soy and hydrolysated rice formula (HRF). Serology was investigated by CAP system technology and immunoblotting. Assessment of the rice formula was carried out by double-blind, placebo-controlled food challenge with rice hydrolysate.

RESULTS

Thirteen children had positive SPT to casein, 10 to lactalbumin, eight to rice and two to rice hydrolysate. Positive serology was found in all patients' sera tested with cow's milk, with soy in 13 sera and with rice in seven. Double-blinded, placebo-controlled challenge with an HRF was negative in all cases.

CONCLUSIONS

Children allergic to cow's milk and soy tolerate an HRF clinically. This suggests that rice hydrolysate may be used as a protein source for children with multiple food-induced reactions.

Earlier smoking habits are associated with higher serum lipids and lower milk fat and polyunsaturated fatty acid content in the first 6 months of lactation

OBJECTIVE

To investigate the relation between maternal smoking habits, plasma lipids and milk fatty acid (FA) content and composition.

DESIGN

Breastfeeding mothers who gave birth to healthy, full-term infants were recruited. Mothers were interviewed on smoking habits, being defined smokers (S) when usually smoking at least five cigarettes per day before pregnancy.

SETTING

Department of Pediatrics, San Paolo Hospital, Milan, Italy.

SUBJECTS

In total, 92 mothers: 61 non-S (NS) and 31 S.

INTERVENTIONS

Pooled hindmilk was collected at the first raise of milk (colostrum stage), 1, 3 and 6 months, and total lipid (TL) content and fatty acid (FA) composition were evaluated. Maternal dietary habits were assessed by a food-frequency questionnaire. Two subsamples (16 NS, 6 S) were investigated after delivery and at 3 months for serum lipids and FA status. At 6 months after delivery, the number of mothers still breastfeeding decreased to 30. Variables were compared using nonparametric tests.

RESULTS

In smoking mothers serum levels of triglycerides, cholesterol and low-density lipoproteins were higher, while those of high-density lipoproteins were lower. TL content in breast milk was similar in the two groups just after delivery but higher in milk from NS at 1 month. TL content and FA absolute amounts of linoleic, arachidonic, alpha-linolenic and docosahexaenoic (DHA) acid in breast milk were lower in S vs NS 1 month after delivery. Also 3 months after delivery, the breast milk of smoking mothers contained less DHA than the breast milk of nonsmoking mothers.

CONCLUSIONS

Maternal cigarette smoking in early pregnancy is associated with higher plasma lipid levels and lower milk TL and DHA content in the first months of lactation.

Monitoring breastfeeding rates in Italy

AIM

to determine the rates of initiation and duration of breastfeeding in Italy in 1995 and 1999, and to examine the adherence to the ten steps to successful breastfeeding recommended by WHO.

METHODS

Two cohorts of mothers who delivered healthy infants in November 1995 (n = 2400) or November 1999 (n = 3500) were interviewed by telephone within 4 wk of delivery when their infants were 3 months of age. Type of breastfeeding was classified according to the WHO definitions. Adherence to the WHO ten steps was evaluated.

RESULTS

Initiation and duration of breastfeeding increased during the 1995-1999 period (p < 0.0001). The rate of breastfeeding at discharge and when the infants where 3 months of age was 83% and 42% in 1995, and 89% and 66% in 1999. The rate of exclusive/predominant breastfeeding at discharge was higher in 1999 than 1995 (78% vs 72%).

CONCLUSION

An increase in initiation and duration of breastfeeding through the first 3 months of age occurred in Italy during the 1995-1999 period, but both breastfeeding duration and observance of the WHO's ten steps are not completely satisfactory yet.

Monitoring breastfeeding rates in Italy: national surveys 1995 and 1999

AIM

To assess and compare the rates of initiation and duration of breastfeeding in Italy in 1995 and 1999, and to examine the adherence to the ten steps to successful breastfeeding recommended by WHO.

METHODS

Two cohorts of mothers who delivered healthy infants in November 1995 (n = 1601) or November 1999 (n = 2450) were interviewed by telephone within 4 wk of delivery and when their infant were 3, 6, 9 and 12 mo of age. Type of breastfeeding was classified according to the WHO definitions. Adherence to the WHO ten steps was evaluated as experienced by the mothers.

RESULTS

Initiation and duration of breastfeeding increased during the 1995-1999 period (p < 0.0001). The rate of breastfeeding at birth, at discharge and when the infants were 3, 6, 9 and 12 mo of age was 85%, 83%, 42%, 19%, 10% and 4%, in 1995 and 91%, 89%, 66%, 47%, 25% and 12% in 1999. The rate of exclusive breastfeeding was higher in 1999 than 1995 at birth (39% vs 30%, p < 0.0001) and at discharge (77% vs 70%, p < 0.0001), but overall no longer duration was observed in 1999. At 4 and 6 mo of age the rate of exclusive breastfeeding was 25% and 8% in 1995 and 31% and 5% in 1999. The adherence to each WHO step was higher in 1999 than in 1995 (p < 0.05) but concomitant adherence was low (<3%).

CONCLUSION

Although an increase in initiation and duration of breastfeeding occurred in Italy during the 1995-1999 period, the duration of breastfeeding and exclusive breastfeeding is currently unsatisfactory, as is adherence to the ten steps specified by WHO. Promotion of breastfeeding and education and improvement in adherence to the WHO recommendations are still needed in Italy.

Long term effects of long chain polyunsaturated fats in hyperphenylalaninemic children

Blood fatty acid status and visual function of 20 treated hyperphenylalaninemic (HPA) children, randomly allocated into two groups to receive supplementation of either long chain polyunsaturated fatty acids (LCPUFA), including docosahexaenoic acid (DHA), or placebo for 12 months, have been investigated three years after the end of the treatment. Although in the LCPUFA group blood DHA levels and P100 wave latency improved at the end of supplementation, they had returned to baseline after three years.

Nutritional value of a rice-hydrolysate formula in infants with cows' milk protein allergy: a randomized pilot study

This study was designed to assess whether a rice-hydrolysate formula allows normal growth and adequate metabolic balance in infants with cows' milk protein allergy. Infants (seven females, nine males; aged 6-14 months) were randomly assigned to receive a rice-hydrolysate formula (n = 8) or a soy formula (control group, n = 8). Standardized growth indices (Z scores) and biochemical parameters were evaluated during a 6-month treatment period. Infants in both groups showed normal growth patterns during the study, and no adverse reactions were seen. Mean plasma biochemical parameters were within the normal ranges, and did not differ between groups. In conclusion, rice-hydrolysate formula may be a nutritionally suitable alternative for infants with cows' milk protein allergy. Larger studies, with satisfactory power, should be undertaken to confirm these findings.

Concentrations of dioxins and other organochlorines (PCBs, DDTs, HCHs) in human milk from Seveso, Milan and a Lombardian rural area in Italy: a study performed 25 years after the heavy dioxin exposure in Seveso

AIM

To investigate whether those who were exposed to high levels of the dioxin TCDD 25 years ago in Seveso, northern Italy still have higher than the expected levels of dioxins in their fat stores, and to investigate the concentrations of dioxins in the breast milk of mothers in Seveso and in two other regions in Italy. The load of vertically transmitted dioxins to the next generation, if being breastfed, was also investigated.

METHODS

As there may be a synergistic effect of mixtures of organic chlorines, the concentrations of pesticides such as DDTs and PCBs have also been studied in the same human milk samples. Breast milk from 12 mothers from Seveso, Central Milan and a Lombardian village was collected for analysis during the first week and 1 and 3 mo after delivery. Individual samples were used for the analysis of pesticides and PCBs, whereas dioxins were analysed in pooled samples from all 12 mothers on each occasion.

RESULTS

In human milk from Seveso, the TCDD concentration in fat calculated on a fresh weight basis was more than twice as high as the level in the other two regions, whereas the concentrations of investigated other toxins were lower in Seveso possible due to induction of the enzyme cytochrome P4501A, which means that the total level of dioxins was the same in all three locations. The congener profile, measured as mean toxic equivalency (TEQ) values, was the same in the Italian samples as previously reported from Stockholm. The calculations are based on the most recent WHO TCDD equivalency factors (TEF). The DDE concentration was higher in the samples from Milan than in the samples from the other two Italian regions, which may be due to the fact that, to a greater extent than in the other regions, Milanese food is imported from countries where DDT is still used as a pesticide.

CONCLUSION

Twenty-five years after the dioxin catastrophe, human milk from mothers in Seveso has concentrations of the highly toxic dioxin congener TCDD that are more than twice as high as those in central Milan and a Lombardian village. This means that breastfed infants in Seveso still store an appreciable amount of TCDD in their body fat. The health consequences of this fact remain to be elucidated. The effect of the high load of DDTs in central Milan also has to be considered

Phenylalanine hydroxylase mutations and phenylalanine-tyrosine metabolism in heterozygotes for phenylalanine hydroxylase deficiency

The aim of this study was to determine whether any relationship exists between the severity of mutation of the phenylalanine hydroxylase (PAH) gene and the plasma concentrations of phenylalanine (Phe) and tyrosine (Tyr) under fasting and semifasting conditions among heterozygotes in a matched case-control study. Parents of patients affected by PAH deficiency (n = 25) detected through the Italian Neonatal Screening Program and referred from January 1994 to June 2000, and parents of healthy children were investigated. In total, 68 subjects without any disease, 34 hyperphenylalaninaemia (HPA) heterozygous parents and 34 age- and gender-matched controls, were recruited. Plasma concentrations of Phe and Tyr in fasting and semifasting (1600 mg Phe oral load) conditions were the main outcome measures. DNA analysis for PAH mutations was performed in all 68 subjects. Compared with controls, heterozygotes showed higher fasting and semifasting Phe concentrations (p < 0.0001), lower semifasting Tyr concentrations (p = 0.015), lower Tyr variations (p = 0.003) and a higher Phe/Tyr ratio (p < 0.0001) in switching from fasting to semifasting conditions. Heterozygotes carrying a severe mutation showed semifasting plasma Tyr concentrations lower than controls (p = 0.019) but not significantly different from Tyr levels found in non-severe carriers (p = 0.197). The Tyr variations were minor in severe carriers than controls (p < 0.001) and non-severe carriers too, although with lower significance (p = 0.089). In six carriers of A403V mutation, parents of mild hyperphenylalaninaemics on an unrestricted diet, significant differences in variations from fasting to semifasting conditions were found compared with parents of patients on a diet.

CONCLUSION

Although the great heterogeneity of PAH mutations limits any general conclusion, the results suggest that monitoring plasma Tyr variations may be more sensitive than plasma Phe in assessing the severity of PAH mutations in HPA heterozygotes.

Proposal of a step-wise follow-up for hepatitis C seropositive mothers and their infants

Mother-to-child transmission of hepatitis C virus can take place in utero, during labour or after birth. Rate of vertical transmission varies widely between surveys but is around 5-6%. Maternal risk factors which may condition perinatal transmission risk are HIV/HCV coinfection, drug use, viral load, viral genotype, type of delivery and breastfeeding. On the basis of recent data, we propose a step-wise follow-up for HCV seropositive mothers and their infants. This proposal might represent an important occasion to unify behaviors in different Obstetrics-Gynecology and Neonatology Units.

Impaired 2',3'-dideoxy-3'-thiacytidine accumulation in T-lymphoblastoid cells as a mechanism of acquired resistance independent of multidrug resistant protein 4 with a possible role for ATP-binding cassette C11

Cellular factors may contribute to the decreased efficacy of chemotherapy in HIV infection. Indeed, prolonged treatment with nucleoside analogues, such as azidothymidine (AZT), 2',3'-deoxycytidine or 9-(2-phosphonylmethoxyethyl)adenine, induces cellular resistance. We have developed a human T lymphoblastoid cell line (CEM 3TC) that is selectively resistant to the antiproliferative effect of 2',3'-dideoxy-3'-thiacytidine (3TC) because the CEM 3TC cells were equally sensitive to AZT, as well as the antimitotic agent, vinblastine. The anti-retroviral activity of 3TC against HIV-1 was also severely impaired in the CEM 3TC cells. Despite similar deoxycytidine kinase activity and unchanged uptake of nucleosides such as AZT and 2'-deoxycytidine, CEM 3TC had profoundly impaired 3TC accumulation. Further studies indicated that CEM 3TC retained much less 3TC. However, despite a small overexpression of multidrug resistance protein (MRP) 4, additional studies with cells specifically engineered to overexpress MRP4 demonstrated there was no impact on either 3TC accumulation or efflux. Finally, an increased expression of the MRP5 homologue, ATP-binding cassette C11 (ABCC11) was observed in the CEM 3TC cells. We speculate that the decreased 3TC accumulation in the CEM 3TC might be due to the upregulation of ABCC11.