Atopic Manifestations Are Underestimated Clinical Features in Various Primary Immunodeficiency Disease Phenotypes.

BACKGROUND AND OBJECTIVES: Atopic manifestations are described as a clinical feature of various primary immunodeficiency disease (PID) phenotypes and are frequently reported in combined immunodeficiencies. The prevalence of atopic manifestations in other PIDs remains largely unknown. Objective: To evaluate the prevalence of atopic manifestations in PIDs other than combined immunodeficiencies and to identify in which PIDs atopic manifestations are most common with the aim of improving patient care. METHODS: A partner-controlled, questionnaire-based study was performed in pediatric and adult PID patients. Data from diagnostic tests to assess atopic manifestations (ie, diagnostic criteria for atopic dermatitis, spirometry, specific IgE against food and inhalant allergens) were collected from adult patients to confirm patient-reported atopic manifestations. RESULTS: Forty-seven children and 206 adults with PIDs and 56 partner-controls completed the questionnaire. Thirty-five pediatric patients (74.5%) and 164 adult patients (79.6%) reported having experienced 1 or more atopic manifestations compared with 28 partner-controls (50.0%). In the comparison of adult patients with partner-controls, prevalence values were as follows: atopic dermatitis, 49.5% vs 27.3% (P=.003); food allergy, 10.7% vs 1.9% (P=.031); asthma, 55.7% vs 14.8% (P<.001); and allergic rhinitis, 49.8% vs 21.8% (P<.001). The frequency of current atopic manifestations reported by patients was higher than the prevalence based on diagnostic tests (atopic dermatitis, 11.2%; food allergy, 1.9%; asthma 16.4%; and allergic rhinitis, 11.5%). CONCLUSION: Atopic manifestations are prevalent clinical features across a broad spectrum of PIDs and, in our cohort, frequently present in patients with combined immunodeficiencies and predominant antibody deficiencies. Atopic manifestations should be evaluated in patients with PIDs.

[Revised multidisciplinary guidelines 'Varicella'; broader indication for post-exposure prophylaxis]. / Herziene multidisciplinaire richtlijn 'Varicella'.

Post-exposure prophylaxis (PEP) with varicella zoster immunoglobulins (VZIG) should be administered as soon as possible after exposure to the virus, but always within ten days; in the previous guidelines this was within 96 hours. In cases of perinatal exposure, PEP with VZIG should be administered to neonates if the mother develops clinical chickenpox between seven days before delivery and seven days after delivery; in the previous guidelines this was between five days before delivery and two days after delivery. A new chapter on the treatment of chickenpox has been added to the guidelines.

Varicella zoster reactivation after hematopoietic stem cell transplant in children is strongly correlated with leukemia treatment and suppression of host T-lymphocyte immunity.

BACKGROUND AND AIMS: Varicella zoster virus (VZV) reactivation following hematopoietic stem cell transplantation (HSCT) may cause significant morbidity and mortality. We undertook a retrospective study to determine the frequency and risk factors associated with VZV reactivation, including underlying disease, the use of fludarabine in high-risk leukemia chemotherapy protocols, and immune status before HSCT. PATIENTS AND METHODS: We studied 163 children who underwent a first HSCT between 2002 and 2008, before introduction of routine VZV prophylaxis on our unit. VZV diagnosis was based on clinical features and supported by polymerase chain reaction on plasma and/or vesical fluid. Patient data and possible risk factors pre- and post HSCT were recorded and compared using a multivariate regression analysis. RESULTS: Within this cohort, 41 (25%) patients developed VZV reactivation during the first year after transplantation at a median of 60 days post HSCT. VZV reactivation occurred more often within the subgroup of patients with acute leukemia compared with the remainder of patients (38% vs. 15%, P < 0.01). Multivariate Cox regression analysis revealed that, besides positive VZV serology in patients pre-HSCT (P = 0.03), acute leukemia as the indication for HSCT remained the only independent risk factor for VZV reactivation (P = 0.025, odds ratio 2.5, 95% confidence interval 1.1-5.6). This was associated with low pre-transplant T-cell counts, especially in the CD4(+) subset. No differences were found in relation to donor type, age, or use of serotherapy. CONCLUSION: VZV reactivation after HSCT predominates in acute leukemia patients and is associated with low T CD4(+) lymphocyte counts. This finding demonstrates the impact of pre-HSCT host immune suppression on VZV reactivation patterns after HSCT.

PorA-specific differences in antibody avidity after vaccination with a hexavalent Men B outer membrane vesicle vaccine in toddlers and school children.

A clinical phase II trial with an experimental hexavalent outer membrane vesicle (OMV) vaccine (HexaMen) containing six different porin A (PorAs) was carried out in toddlers (2-3 years) and schoolchildren (7-8 years) in The Netherlands. HexaMen exists of two OMVs each containing three different PorA types. The serum bactericidal activity (SBA) after vaccination against the six PorAs was significantly different and was higher in toddlers than in schoolchildren. After vaccination the SBA against P1.5-2,10 was 4-6 times higher than against P1.7-2,4. The aim of this study was to test whether the differences in SBA could be explained by a difference in subtype-specific antibody avidity maturation. The avidity index (AI) of antibodies against three subtypes (PorA types P1.5-2,10; P1.12-1,13 and P1.7-2,4) was measured by ELISA and evaluated in relation to SBA. A significant avidity maturation for the 3 PorA subtypes was found. This maturation was most pronounced for P1.5-2,10 (mean AI = 72%), correlating with the highest SBA titres. Generally, the avidity titre correlated best with SBA. No differences in avidity indices against the three tested PorAs were found between toddlers and school children indicating that avidity maturation induced by this vaccine is not age-dependent.

Cross-reactivity of antibodies against PorA after vaccination with a meningococcal B outer membrane vesicle vaccine.

The cross-reactivity of PorA-specific antibodies induced by a monovalent P1.7-2,4 (MonoMen) and/or a hexavalent (HexaMen) meningococcal B outer membrane vesicle vaccine (OMV) in toddlers and school children was studied by serum bactericidal assays (SBA). First, isogenic vaccine strains and PorA-identical patient isolates were compared as a target in SBA, to ensure that the vaccine strains are representative for patient isolates. Geometric mean titers (GMTs) in SBA against patient isolates with subtypes P1.5-2,10 and P1.5-1,2-2 after vaccination with HexaMen were generally lower than those against vaccine strains with the same subtype, although the percentage of vaccine responders (> or =4-fold increase in SBA after vaccination) was not affected. Using various P1.7-2,4 patient isolates, GMTs as well as the number of vaccine responders were higher than for the P1.7-2,4 vaccine strain, indicating that the use of the P1.7-2,4 vaccine strain may have underestimated the immunogenicity of this subtype in HexaMen. Secondly, the cross-reactivity of antibodies induced by MonoMen and HexaMen was studied using several patient isolates that differed from the vaccine subtypes by having minor antigenic variants of one variable region (VR), by having a completely different VR or by having a different combination of VRs. MonoMen induced P1.4-specific antibodies that were cross-reactive with P1.4 variants P1.4-1 and P1.4-3. HexaMen induced a broader cross-reactive antibody response against various patient isolates with one VR identical to a vaccine subtype or a combination of VRs included in HexaMen. Cross-reactivity, measured by a fourfold increase in SBA after vaccination, against these strains ranged from 23 to 92% depending on the subtype of the tested strain and was directed against both VR1 and VR2. The extended cross-reactivity of vaccinee sera induced by HexaMen against antigenic variants has important favorable implications for meningococcal B OMV vaccine coverage.

Antibody avidity and immunoglobulin G isotype distribution following immunization with a monovalent meningococcal B outer membrane vesicle vaccine.

The avidity maturation and immunoglobulin G (IgG) isotype distribution of antibodies after vaccination with a meningococcal B outer membrane vesicle (OMV) vaccine were evaluated as indicators of protective immunity. Pre- and postvaccination sera from 134 healthy toddlers (ages, 2 to 3 years) immunized with a monovalent meningococcal B OMV (serosubtype P1.7-2,4) vaccine adsorbed with AlPO(4) or Al(OH)(3) were analyzed by enzyme-linked immunosorbent assay (ELISA) methods. The children were vaccinated three times with intervals of 3 to 6 weeks between vaccinations or twice with an interval of 6 to 10 weeks between vaccinations. A booster was given after 20 to 40 weeks. The avidity index (AI) of antibodies increased significantly during the primary series of vaccinations and after the booster was given. No differences in AIs were found when the results obtained with the two vaccination schedules or with the two adjuvants were compared. After vaccination, IgG1 was the predominant IgG isotype, followed by IgG3. No IgG2 or IgG4 was detected. There was a strong correlation between serum bactericidal activity (SBA) and ELISA titers (r = 0.85 [P < 0.0001] for total IgG, r = 0.83 for IgG1 [P < 0.0001], r = 0.82 for IgG3 [P < 0.0001], and r = 0.84 [P < 0.0001] for the avidity titer). When two subgroups with similar anti-OMV IgG levels were compared before and after the booster vaccination, the higher AI after the booster vaccination was associated with significantly increased SBA. We concluded that avidity maturation occurs after vaccination with a monovalent meningococcal B OMV vaccine, especially after boosting, as indicated by a significant increase in the AI. Vaccination with the monovalent OMV vaccine induced mainly IgG1 and IgG3 isotypes, which are considered to be most important for protection against meningococcal disease. An increase in the AI of antibodies is associated with increased SBA, independent of the level of specific IgG and the IgG isotype distribution. Measuring the AI and IgG isotype distribution of antibodies after vaccination can be a supplementary method for predicting protective immunity for evaluation in future phase III trials with meningococcal serogroup B vaccines.

Persistence of clones of coagulase-negative staphylococci among premature neonates in neonatal intensive care units: two-center study of bacterial genotyping and patient risk factors.

From 1 January 1995 until 1 January 1996, we studied the molecular epidemiology of blood isolates of coagulase-negative staphylococci (CoNS) in the Neonatal Intensive Care Units (NICUs) of the Sophia Children's Hospital (SCH; Rotterdam, The Netherlands) and the Wilhelmina Children's Hospital (WCH; Utrecht, The Netherlands). The main goal of the present study was to detect putatively endemic clones of CoNS persisting in these NICUs. Pulsed-field gel electrophoresis was used to detect the possible presence of endemic clones of clinical significance. In addition, clinical data of patients in the SCH were analyzed retrospectively to identify risk factors for the acquisition of positive blood cultures. In both centers, endemic CoNS clones were persistently present. Thirty-three percent of the bacterial isolates derived from blood cultures in the SCH belonged to a single genotype. In the WCH, 45% of all bacterial strains belonged to a single clone. These clones were clearly different from each other, which implies that site specificity is involved. Interestingly, we observe that the clonal type in the SCH differed significantly from the incidentally occurring strains with respect to both the average pH and partial CO2 pressure of the patient's blood at the time of bacterial culture. We found that the use of intravascular catheters, low gestational age, and a long hospital stay were important risk factors for the development of a putative CoNS infection. When the antibiotic susceptibility of the bacterial isolates was assessed, a clear correlation between the nature of the antibiotics most frequently used as a first line of defense versus the resistance profile was observed. We conclude that the intensive use of antibiotics in an NICU setting with highly susceptible patients causes selection of multiresistant clones of CoNS which subsequently become endemic.