Stuart P. Adler

Persistent and Selective Deficiency of CD4+ T Cell Immunity to Cytomegalovirus in Immunocompetent Young Children

Healthy young children who acquire CMV have prolonged viral shedding into the urine and saliva, but whether this is attributable to limitations in viral-specific immune responses has not been explored. In this study, we found that otherwise immunocompetent young children after recent primary CMV infection accumulated markedly fewer CMV-specific CD4+ T cells that produced IFN-γ than did adults. These differences in CD4+ T cell function persisted for more than 1 year after viral acquisition, and did not apply to CMV-specific IFN-γ production by CD8+ T cells. The IFN-γ-producing CD4+ T cells of children or adults that were reactive with CMV Ags were mainly the CCR7low cell subset of memory (CD45R0highCD45RAlow) cells. The decreased IFN-γ response to CMV in children was selective, because their CCR7low memory CD4+ T cells and those of adults produced similar levels of this cytokine after stimulation with staphylococcal enterotoxin B superantigen. CD4+ T cells from children also had reduced CMV-specific IL-2 and CD154 (CD40 ligand) expression, suggesting an early blockade in the differentiation of viral-specific CD4+ T cells. Following CMV acquisition, children, but not adults, persistently shed virus in urine, and this was observable for at least 29 mo postinfection. Thus, CD4+ T cell-mediated immunity to CMV in humans is generated in an age-dependent manner, and may have a substantial role in controlling renal viral replication and urinary shedding.

Cytomegalovirus and Child Day Care

Abstract To determine whether day-care workers acquire cytomegalovirus infection from the children they care for, we studied 610 women employed at 34 day-care centers over two years. Forty-one percent of the caretakers were seropositive for cytomegalovirus. After adjustment for the effects of race, marital status, and age on seropositivity, the women who cared for children younger than two years of age had a significantly higher seropositivity rate (46 percent) than the women who cared for children older than two years of age (35 percent) (relative risk, 1.29; 95 percent confidence interval, 1.05 to 1.57; P<0.02). Of 202 initially seronegative caretakers (observed for an average of 305 days per woman), 19 seroconverted, for an annual seroconversion rate of 11 percent. This rate was significantly higher than the 2 percent annual rate of seroconversion among 229 seronegative women (11 of whom seroconverted) in a comparison group of female hospital employees observed for an average of 781 days per woman (rel...

Prevention of child-to-mother transmission of cytomegalovirus by changing behaviors: a randomized controlled trial.

BACKGROUND To determine whether a behavioral prevention approach reduces child-to-parent transmission of cytomegalovirus. METHODS Subjects were seronegative mothers whose child was less than 36 months of age and was shedding cytomegalovirus. Nonpregnant women were randomly assigned to three groups. Mothers in the education group (E) were given instructions about protective behaviors (frequent hand washing, wearing latex gloves) and risky behaviors to avoid (intimate contact with the child). Disposable diapers, liquid soap and latex gloves were provided. During biweekly home visits glove and soap use were monitored for an indirect objective measure of adherence to the protective behaviors. Throughout the study mothers self-reported the frequency they engaged in protective and risky behaviors. In addition to the procedures for Group E the adherence and education group (A) also received social reinforcement for adherence and problem solving for any perceived problems with the behavioral recommendations. The control group (C) received no intervention. A fourth group of pregnant women received an intervention equivalent to that of the education group. RESULTS Eight of 17 women in Group C and 4 of 11 women in Group E seroconverted. For both E and Group C the average time from enrollment to infection was 4 months (range, 2 to 7 months). Two of 8 women in Group A seroconverted (1 at 3 months and 1 at 8 months). None of 14 pregnant women observed for an average of 8.4 months during pregnancy seroconverted. CONCLUSIONS These results suggest that intervention for pregnant women is effective because pregnant women will perceive a higher risk and be more motivated to adhere to recommendations than nonpregnant women.

Linezolid versus vancomycin for treatment of resistant Gram-positive infections in children

Background. Pediatric infections caused by resistant Gram-positive infections are an increasing concern with limited treatment options. Linezolid, a new oxazolidinone, is active against staphylococci, streptococci and enterococci. Objective. To assess clinical efficacy and safety of linezolid vs. vancomycin in antibiotic-resistant Gram-positive infections in children. Design. Hospitalized children (birth to 12 years of age) with nosocomial pneumonia, complicated skin/skin structure infections, catheter-related bacteremia, bacteremia of unknown source or other infections caused by Gram-positive bacteria were randomized 2:1 to receive linezolid intravenously followed by oral linezolid or vancomycin and then by an appropriate oral agent. Treatment duration was 10 to 28 days. Results. There were 321 patients enrolled (linezolid 219, vancomycin 102). Clinical cure rates were 79% vs. 74% (P = 0.36) and 89% vs. 85% (P = 0.31) for linezolid and vancomycin in intent-to-treat and clinically evaluable patients, respectively. Cure rates were similar by age and infection diagnosis. Pathogen eradication rates in microbiologically evaluable patients were high for linezolid and vancomycin, respectively, for methicillin-susceptible S. aureus (95% vs. 94%; P = 0.82), methicillin-resistant S. aureus (88% vs. 90%; P = 0.89) and methicillin-resistant coagulase-negative staphylococci (85% vs. 83%, P = 0.87). In clinically evaluable patients, linezolid-treated patients required significantly fewer days of intravenous therapy compared with vancomycin-treated patients (8.0 ± 4.8; 10.9 ± 5.8 days, respectively; P < 0.001). In addition significantly fewer linezolid-treated patients had drug-related adverse events than did vancomycin-treated patients (19% vs. 34%, respectively; P = 0.003). Hematologic events were uncommon and similar between treatment groups. Conclusions. Linezolid was well-tolerated and as effective as vancomycin in treating serious Gram-positive infections in children.

Cytomegalovirus vaccines fail to induce epithelial entry neutralizing antibodies comparable to natural infection

Antibodies that neutralize cytomegalovirus (CMV) entry into fibroblasts are predominantly directed against epitopes within virion glycoproteins that are required for attachment and entry. However, the mechanism of CMV entry into epithelial and endothelial cells differs from fibroblast entry. Using assays that simultaneously measured neutralizing activities against CMV entry into fibroblasts and epithelial cells, we found that human immune sera and CMV-hyperimmuneglobulins have on on average 48-fold higher neutralizing activities against epithelial cell entry compared to fibroblast entry, suggesting that natural CMV infections elicit neutralizing antibodies that are epithelial entry-specific. This activity could not be adsorbed with recombinant gB. The Towne vaccine and the gB/MF59 subunit vaccine induced epithelial entry-specific neutralizing activities that were on on average 28-fold (Towne) or 15-fold (gB/MF59) lower than those observed following natural infection. These results suggest that CMV vaccine efficacy may be enhanced by the induction of epithelial entry-specific neutralizing antibodies.

A Canarypox Vector Expressing Cytomegalovirus (CMV) Glycoprotein B Primes for Antibody Responses to a Live Attenuated CMV Vaccine (Towne)

To develop a vaccine against cytomegalovirus (CMV), a canarypox virus (ALVAC) expressing CMV glycoprotein (gB) was evaluated alone or in combination with a live, attenuated CMV vaccine (Towne). Three doses of 106.5 TCID50 of ALVAC-CMV(gB) induced very low neutralizing or ELISA antibodies in most seronegative adults. However, to determine whether ALVAC-CMV(gB) could prime for antibody responses, 20 seronegative adults randomly received either 106.8 TCID50 of ALVAC-CMV(gB) or 106.8 TCID50 of ALVAC-RG, expressing the rabies glycoprotein, administered at 0 and 1 month, with all subjects receiving a dose of 103.5 pfu of the Towne vaccine at 90 days. For subjects primed with ALVAC-CMV(gB), neutralizing titers and ELISA antibodies to CMV(gB) developed sooner, were much higher, and persisted longer than for subjects primed with ALVAC-RG. All vaccines were well tolerated. These results demonstrate that ALVAC-CMV(gB) primes the immune system and suggest a combined-vaccine strategy to induce potentially protective levels of neutralizing antibodies.

Manifestations and treatment of human parvovirus B19 infection in immunocompromised patients.

We diagnosed infections from human parvovirus B19 in three patients by using dot-blot hybridization and a polymerase chain reaction to detect B19 DNA and using an enzyme immunoassay to detect IgG and IgM to B19. For 5 months a 5-year-old boy with acute lymphoblastic leukemia in remission had anemia without reticulocytes or bone marrow erythrocyte precursors. His serum lacked IgG and IgM to B19 but contained B19 DNA. He received gamma globulin intravenously (0.4 gm/kg/day for 5 days); his viremia promptly cleared and reticulocytosis developed. A 14-year-old boy with acute lymphoblastic leukemia in remission had fever, rash, neutropenia (less than 300 leukocytes/mm3), and a hemophagocytic syndrome lasting 3 weeks. His serum contained IgM to B19 and B19 DNA. Without therapy, IgG to B19 developed; although low levels of B19 DNA persisted, the leukocyte count returned to normal. In a 19-year-old patient with systemic lupus erythematosus and hemolytic anemia, an aplastic crisis lasted 2 weeks. Her serum lacked IgG and IgM to B19 but contained B19 DNA. Without therapy, IgG and IgM to B19 appeared, viremia diminished, and reticulocytosis occurred. These patients illustrate the varied manifestations of chronic B19 infections, the importance of DNA detection for diagnosis, and the possible efficacy of gamma globulin therapy.

Cytomegalovirus infections in neonates acquired by blood transfusions

One hundred seventy-eight newborns were cultured for cytomegalovirus (CMV) on admission and weekly after 4 weeks of age until discharge. Eight (all with birth weights of 1050 g or less) acquired CMV while hospitalized. At least seven of the infected infants were born to CMV-seronegative mothers. The risk for seronegative infants weighing less than 1250 g of acquiring CMV was 24%. There was no correlation between duration of hospitalization and birth weight for infants hospitalized over 30 days. There was a significant correlation (P < 0.0001) between the number of blood donors for an infant and the acquisition of CMV. Infected infants received blood from eight or more donors prior to CMV shedding. Infected low birth weight infants received blood from an average of 6.5 CMV antibody-positive donors, while uninfected low birth weight infants received blood from an average of 3.1 CMV antibody-positive donors. No infant received nonmaternal breast milk. After acquiring CMV, three infants died (only one was autopsied and had proved disseminated CMV disease), two developed hepatitis and one developed hepatosplenomegaly. These results suggest that acquired CMV infection is a significant risk to seronegative low birth weight infants who receive blood from seropositive blood donors.

Administration of oral acyclovir suppressive therapy after neonatal herpes simplex virus disease limited to the skin, eyes and mouth: Results of a phase I/II trial

BACKGROUND Neonatal herpes simplex virus (HSV) infections limited to the skin, eyes and mouth (SEM) can result in neurologic impairment. A direct correlation exists between the development of neurologic deficits and the frequency of cutaneous HSV recurrences. Thus, the National Institutes of Allergy and Infectious Diseases Collaborative Antiviral Study Group conducted a Phase I/II trial of oral acyclovir therapy for the suppression of cutaneous recurrences after SEM disease in 26 neonates. METHODS Infants < or = 1 month of age with virologically confirmed HSV-2 SEM disease were eligible for enrollment. Suppressive oral acyclovir therapy (300 mg/m2/dose given either twice daily or three times per day) was administered for 6 months. RESULTS Twelve (46%) of the 26 infants developed neutropenia (< 1000 cells/mm3) while receiving acyclovir. Thirteen (81%) of the 16 infants who received drug 3 times per day experienced no recurrences of skin lesions while receiving therapy. In comparison, a previous Collaborative Antiviral Study Group study found that only 54% of infants have no cutaneous recurrences in the 6 months after resolution of neonatal HSV disease if oral acyclovir suppressive therapy is not initiated. In one infant, HSV DNA was detected in the cerebrospinal fluid during a cutaneous recurrence, and an acyclovir-resistant HSV mutant was isolated from another patient during the course of the study. CONCLUSIONS Administration of oral acyclovir can prevent cutaneous recurrences of HSV after neonatal SEM disease. The effect of such therapy on neurologic outcome must be assessed in a larger, Phase III study. As such, additional investigation is necessary before routine use of suppressive therapy in this population can be recommended.

Placental Enlargement in Women with Primary Maternal Cytomegalovirus Infection Is Associated with Fetal and Neonatal Disease

BACKGROUND Serological testing for primary maternal cytomegalovirus (CMV) infection during pregnancy is not routine, but ultrasound studies are routine. Therefore, we evaluated placental thickening in women with primary CMV infection during pregnancy. METHODS The study included 92 women with primary CMV infection during pregnancy and 73 CMV-seropositive pregnant women without primary CMV infection. Neonatal CMV transmission was determined by CMV culture of urine samples. Thirty-two women were treated with CMV hyperimmune globulin to either prevent or treat intrauterine CMV infection. Maximal placental thickness was measured by longitudinal (nonoblique) scanning with the ultrasound beam perpendicular to the chorial dish. Programmed placental ultrasound evaluations were performed from 16 to 36 weeks of gestation. RESULTS At each measurement between 16 and 36 weeks of gestation, women with primary CMV infection who had a fetus or newborn with CMV disease had placentas that were significantly thicker than those of women with primary CMV infection who did not have a diseased fetus or newborn (P<.0001); the latter group, in turn, had placentas that were significantly thicker than those of seropositive control subjects (P<.0001). For both women with and women without diseased fetuses or newborns, receipt of hyperimmune globulin after primary CMV infection was associated with statistically significant reductions in placental thickness (P<.001). Placental vertical thickness values, which are predictive of primary maternal infection, were observed at each measurement from 16 to 36 weeks of gestation, and cutoff values ranged from 22 mm to 35 mm, with the best sensitivity and specificity at 28 and 32 weeks of gestation. CONCLUSIONS Primary maternal CMV infection and fetal or neonatal disease are associated with sonographically thickened placentas, which respond to administration of hyperimmune globulin. These observations suggest that many of the manifestations of fetal and neonatal disease are caused by placental insufficiency.