[Feasibility of the 'Uitblinkers' intervention to improve toothbrushing among children: a pilot study]. / Toepasbaarheid van de 'Uitblinkers-interventie' om tandenpoetsen bij kinderen te verbeteren: een pilotonderzoek.

In 2017, the 'Uitblinkers' intervention was developed to improve toothbrushing behaviour among young children. This interview method focuses on identifying parents' barriers to brushing their children's teeth, and promoting parenting strategies to tackle the identified barriers. Twenty-one trained dental therapists from twelve dental practices applied the 'Uitblinkers' intervention among parents of three-year-old children. Nine months after the training, focus group- and telephone interviews were conducted to evaluate the feasibility and appreciation of the intervention in dental practice. Findings of this study show that the 'Uitblinkers' intervention offers a feasible approach to improve children's toothbrushing behaviour. Dental therapists were generally positive about the interview method, the supporting materials and the reactions of parents. Some (logistic) barriers to adoption were identified which, if resolved, would improve the implementation of the intervention in dental practice.

Towards a European health research and innovation cloud (HRIC).

The European Union (EU) initiative on the Digital Transformation of Health and Care (Digicare) aims to provide the conditions necessary for building a secure, flexible, and decentralized digital health infrastructure. Creating a European Health Research and Innovation Cloud (HRIC) within this environment should enable data sharing and analysis for health research across the EU, in compliance with data protection legislation while preserving the full trust of the participants. Such a HRIC should learn from and build on existing data infrastructures, integrate best practices, and focus on the concrete needs of the community in terms of technologies, governance, management, regulation, and ethics requirements. Here, we describe the vision and expected benefits of digital data sharing in health research activities and present a roadmap that fosters the opportunities while answering the challenges of implementing a HRIC. For this, we put forward five specific recommendations and action points to ensure that a European HRIC: i) is built on established standards and guidelines, providing cloud technologies through an open and decentralized infrastructure; ii) is developed and certified to the highest standards of interoperability and data security that can be trusted by all stakeholders; iii) is supported by a robust ethical and legal framework that is compliant with the EU General Data Protection Regulation (GDPR); iv) establishes a proper environment for the training of new generations of data and medical scientists; and v) stimulates research and innovation in transnational collaborations through public and private initiatives and partnerships funded by the EU through Horizon 2020 and Horizon Europe.

ß-1 tubulin R307H SNP alters microtubule dynamics and affects severity of a hereditary thrombocytopenia.

BACKGROUND: Single nucleotide polymorphisms (SNPs) in platelet-associated genes partly explain inherent variability in platelet counts. Patients with monoallelic Bernard Soulier syndrome due to the Bolzano mutation (GPIBA A156V) have variable platelet counts despite a common mutation for unknown reasons. OBJECTIVES: We investigated the effect of the most common SNP (R307H) in the hematopoietic-specific tubulin isotype ß-1 in these Bernard Soulier patients and potential microtubule-based mechanisms of worsened thrombocytopenia. PATIENTS/METHODS: Ninety-four monoallelic Bolzano mutation patients were evaluated for the R307H ß-1 SNP and had platelet counts measured by three methods; the Q43P SNP was also evaluated. To investigate possible mechanisms underlying this association, we used molecular modeling of ß-1 tubulin with and without the R307H SNP. We transfected SNP or non-SNP ß-1 tubulin into MCF-7 and CMK cell lines and measured microtubule regrowth after nocodazole-induced depolymerization. RESULTS: We found that patients with at least one R307H SNP allele had significantly worse thrombocytopenia; manual platelet counting revealed a median platelet count of 124 in non-SNP patients and 76 in SNP patients (both ×10(9)  L(-1) ; P < 0.01). The Q43P SNP had no significant association with platelet count. Molecular modeling suggested a structural relationship between the R307H SNP and microtubule stability via alterations in the M-loop of ß tubulin; in vitro microtubule recovery assays revealed that cells transfected with R307H SNP ß-1 had significantly impaired microtubule recovery. CONCLUSIONS: Our data show that the R307H SNP is significantly associated with the degree of thrombocytopenia in congenital and acquired platelet disorders, and may affect platelets by altering microtubule behavior.

Practitioner review: evidence-based practice guidelines on alcohol and drug misuse among adolescents: a systematic review.

BACKGROUND: Context-specific evidence-based guidelines on how to prevent and treat substance misuse among adolescents are currently lacking in many countries. Due to the time consuming nature of de novo guideline development, the ADAPTE collaboration introduced a methodology to adapt existing guidelines to a local context. An important step in this method is a systematic review to identify relevant high-quality evidence-based guidelines. This study describes the results of this step for the development of guidelines on adolescent alcohol and drug misuse in Belgium. METHODS: Rigorous systematic review methodology was used. This included searches of electronic databases (Medline, Embase, Cinahl, PsychInfo, and ERIC in June 2011), websites of relevant organizations, and reference lists of key publications. Experts in the field were also contacted. Included were Dutch, English, French, or German evidence-based practice guidelines from 2006 or later on the prevention, screening, assessment, or treatment of alcohol or illicit drug misuse in persons aged 12-18 years. Two independent reviewers assessed the quality of the guidelines using the AGREE II (Appraisal of Guidelines for Research and Evaluation) instrument. SCOPE: This overview provides a framework of current knowledge in adolescent alcohol and drug misuse prevention and treatment. RESULTS: This systematic review identified 32 relevant evidence-based guidelines on substance misuse among adolescents. Nine guidelines were judged to be of high quality; of which four had recommendations specifically on adolescents: one on school-based prevention, one on substance misuse prevention in vulnerable young people and two on alcohol misuse with specific sections for the adolescent population. There were few commonalities as guidelines focused on different target groups, professional disciplines and type and level of substance misuse. Evidence to support the recommendations was sparse, and many recommendations were based on expert consensus or on studies among adults. Also, the link between evidence and recommendations was often unclear. CONCLUSIONS: There are a substantial number of guidelines addressing substance misuse in adolescents. However, only four high-quality guidelines included recommendations specific for adolescents. The current level of evidence that underpins the recommendations in these high-quality guidelines is low.

Decreased plasma cytokines are associated with low platelet counts in aplastic anemia and immune thrombocytopenic purpura.

BACKGROUND: We previously found plasma levels of CD40 ligand (CD40L), chemokine (C-X-C motif) ligand 5 (CXCL5), chemokine (C-C motif) ligand 5 (CCL5) and epidermal growth factor (EGF) to be low in aplastic anemia (AA) patients and to be correlated with platelet count. OBJECTIVES: To study the association of CD40L, CXCL5, CCL5 and EGF with platelets. METHODS: We measured cytokines in the plasma of immune thrombocytopenic purpura (ITP) and AA patients using the Luminex assay and confirmed the results in a mouse model and in vitro experiments. RESULTS: Both ITP and AA showed similarly low levels of CD40L, CXCL5, CCL5 and EGF, compared with healthy controls. In ITP, levels of these proteins were significantly greater in patients with higher platelet counts than in those with lower platelet counts. In a murine thrombocytopenia model, levels of CD40L, CXCL5, CCL5 and EGF decreased with platelet count after immune-mediated destruction, while the cytokine levels increased when the platelet count recovered. In vitro, concentrations of these cytokines in the supernatants of platelet suspensions were proportional to platelet numbers, and levels in sera prepared by simple blood coagulation were equivalent to those in platelet-rich plasma-converted sera. mRNA expression for CXCL5, CCL5 and EGF was higher in platelets than in megakaryocytes, peripheral blood mononuclear cells, granulocytes and non-megakaryocytic bone marrow cells. CONCLUSIONS: Plasma CD40L, CXCL5, CCL5 and EGF are mainly platelet-derived, suggesting a role of platelets in immune responses and inflammation. Measurement of CD40L, CXCL5, CCL5 and EGF in human blood allowed testable inferences concerning physiology and pathophysiology in quantitative platelet disorders.

Differences in platelet function in patients with acute myeloid leukemia and myelodysplasia compared to equally thrombocytopenic patients with immune thrombocytopenia.

BACKGROUND: Severe thrombocytopenia is a major risk factor for hemorrhage, but platelet function and bleeding risk at low platelet counts are poorly understood, because of the limitations of platelet function testing at very low platelet counts. OBJECTIVES: To examine and compare platelet function in severely thrombocytopenic patients with acute myeloid leukemia (AML) or myelodysplasia (MDS) with that in patients with immune thrombocytopenia (ITP). METHODS: Whole blood flow cytometric measurement of platelet activation and platelet reactivity to agonists was correlated with the immature platelet fraction (IPF) and bleeding symptoms. RESULTS: Patients with AML/MDS had smaller platelets, lower IPF and substantially lower platelet surface expression of activated glycoprotein (GP)IIb-IIIa and GPIb, both with and without addition of ex vivo ADP or thrombin receptor-activating peptide, than patients with ITP. In both ITP and AML/MDS patients, increased platelet surface GPIb on circulating platelets and expression of activated GPIIb-IIIa and GPIb on ex vivo activated platelets correlated with a higher IPF. Whereas platelet reactivity was higher for AML/MDS patients with bleeding than for those with no bleeding, platelet reactivity was lower for ITP patients with bleeding than for those with no bleeding. CONCLUSIONS: AML/MDS patients have lower in vivo platelet activation and ex vivo platelet reactivity than patients with ITP. The proportion of newly produced platelets correlates with the expression of platelet surface markers of activation. These differences might contribute to differences in bleeding tendency between AML/MDS and ITP patients. This study is the first to define differences in platelet function between AML/MDS patients and ITP patients with equivalent degrees of thrombocytopenia.

6th International Immunoglobulin Symposium: poster presentations.

The posters presented at the 6th International Immunoglobulin Symposium covered a wide range of fields and included both basic science and clinical research. From the abstracts accepted for poster presentation, 12 abstracts were selected for oral presentations in three parallel sessions on immunodeficiencies, autoimmunity and basic research. The immunodeficiency presentations dealt with novel, rare class-switch recombination (CSR) deficiencies, attenuation of adverse events following IVIg treatment, association of immunoglobulin (Ig)G trough levels and protection against acute infection in patients with X-linked agammaglobulinaemia (XLA) and common variable immunodeficiency (CVID), and the reduction of class-switched memory B cells in patients with specific antibody deficiency (SAD). The impact of intravenous immunoglobulin on fetal alloimmune thrombocytopenia, pregnancy and postpartum-related relapses in multiple sclerosis and refractory myositis, as well as experiences with subcutaneous immunoglobulin in patients with multi-focal motor neuropathy, were the topics presented in the autoimmunity session. The interaction of dendritic cell (DC)-SIGN and alpha2,6-sialylated IgG Fc and its impact on human DCs, the enrichment of sialylated IgG in plasma-derived IgG, as wells as prion surveillance and monitoring of anti-measles titres in immunoglobulin products, were covered in the basic science session. In summary, the presentations illustrated the breadth of immunoglobulin therapy usage and highlighted the progress that is being made in diverse areas of basic and clinical research, extending our understanding of the mechanisms of immunoglobulin action and contributing to improved patient care.

Diagnosis and management of the fetus and neonate with alloimmune thrombocytopenia.

Fetal and neonatal alloimmune thrombocytopenia (AIT) is the commonest cause of severe thrombocytopenia in neonates, and of intracranial hemorrhage (ICH) in term neonates [1] (J Trop Pediatr, 1999; 45: 237). If a newborn is affected with AIT, the next child will likely be more severely affected, and therefore fetal thrombocytopenia will begin early in gestation [2, 3] (Arch Neurol, 1984; 41: 30; N Engl J Med 1997; 337: 22). This creates a risk of in utero ICH even if there was not one in the previous pregnancy. There are new developments in AIT in regard to diagnosis, treatment, and screening which will be the focus of this review.

Prospective evaluation of a new platelet glycoprotein (GP)-specific assay (PakAuto) in the diagnosis of autoimmune thrombocytopenia (AITP).

Assays measuring platelet-associated immunoglobulin G (PAIgG), while highly sensitive, lack specificity in diagnosing autoimmune thrombocytopenia (AITP). We prospectively evaluated a new commercially available glycoprotein (GP)-specific assay, the PakAuto (GTI, Brookfield, WI), for its clinical usefulness in distinguishing immune from nonimmune thrombocytopenia (TP), in 216 patients with autoimmune TP (both primary "idiopathic" and "secondary") and 46 patients with TP due to other causes. This assay is designed to detect both platelet-associated (direct assay) and plasma (indirect assay) antiplatelet antibodies specific for GPs IIb/IIIa, Ib/IX, and Ia/IIa. The mean platelet counts of the immune (79 +/- 7 x 10(9)/L) and nonimmune groups (78 +/- 7 x 10(9)/L), were similar (P=0.95). The direct assay was positive in 114/216 patients with AITP (53%), and 13/46 with nonimmune TP (28%). Among the AITP group, the majority (61%) of patients with positive test results had autoantibodies reactive against all three GP targets. The sensitivity, specificity, positive, and negative predictive values for the direct PakAuto were 53%, 72%, 90%, and 24%, respectively, comparable to previously published experience of GP-specific assays. However, in some cases of TP due to nonimmune cause, the PakAuto was highly specific. Only 3 of 22 patients with gestational and 1 of 8 with familial/congenital TP had a positive direct assay, indicating that the test may be particularly useful for excluding an immune etiology for TP in certain patient subgroups.

T cell receptor VB repertoire diversity in patients with immune thrombocytopenia following splenectomy.

In recent years, a pathophysiological role for T cells in immune thrombocytopenia (ITP) has been established. We applied cDNA size distribution analysis of the T cell receptor (TCR) beta-variable (VB) complementarity-determining region 3 (CDR3) in order to investigate T cell repertoire diversity among immune thrombocytopenia patients who had either responded or not responded to splenectomy, and compared them to normal controls. ITP patients who had had a durable platelet response to splenectomy showed a mean 2.8 +/- 2.1 abnormal CDR3 size patterns per patient, similar to healthy volunteers (2.9 +/- 2.0 abnormal CDR3 size patterns). In contrast, patients unresponsive to splenectomy demonstrated evidence of significantly more clonal T cell expansions than patients who had responded to splenectomy or controls (11.3 +/- 3.3 abnormal CDR3 size patterns per patient; P < 0.001). Of the VB subfamilies analysed, VB3 and VB15 correlated with response or non-response to splenectomy, each demonstrating oligoclonality in non-responding patients (P < 0.05). These findings suggest that removal of the spleen may lead directly or indirectly to reductions in T cell clonal expansions in responders, or that the extent of T cell clonality impacts responsiveness to splenectomy in patients with ITP.

Fetal and neonatal thrombopoietin levels in alloimmune thrombocytopenia.

Thrombopoietin (Tpo) is the main hematopoietic growth factor for platelet production. Plasma Tpo levels in autoimmune thrombocytopenic patients are normal or slightly elevated. Although thrombocytopenia exists, Tpo levels are not increased because the produced megakaryocytes and platelets can bind circulating Tpo, thereby normalizing Tpo levels. In this study, plasma samples from fetuses and neonates with neonatal alloimmune thrombocytopenia (NAIT), a different form of immune thrombocytopenia, were measured. Umbilical cord samples from 50 fetuses before treatment because of severe thrombocytopenia and 51 fetuses after treatment, and peripheral blood samples of 21 untreated newborns with NAIT were analyzed. As controls, plasma Tpo levels were determined in 21 umbilical cord samples of 14 nonthrombocytopenic fetuses with hemolytic disease resulting from red blood cell alloimmunization and in umbilical cord samples of 51 healthy newborns. The values were also compared with the plasma Tpo levels in 193 healthy adults. Mean Tpo levels from the groups of fetuses and neonates, including both NAIT and control plasma, were slightly but significantly elevated compared with levels in healthy adults. Tpo levels in NAIT samples were not significantly different from the levels in hemolytic disease samples or in samples from healthy newborns. Thus, as in autoimmune thrombocytopenic patients, normal Tpo levels are present in NAIT patients.

Anti-platelet antibodies associated with the Canale-Smith syndrome bind to the same platelet glycoprotein complexes as those of idiopathic thrombocytopenic purpura patients.

The Canale-Smith syndrome (CSS) is an inherited disease characterized by massive lymphadenopathy, hepatosplenomegaly and systemic autoimmunity to erythrocytes and platelets. Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disease in which approximately 60-80% of patients have anti-platelet antibodies directed against specific platelet glycoprotein complexes (GPCs) located on their membrane: GP IIb/IIIa, GPIb/IX, and GPIa/IIa. Almost all (95-100%) of the antibody-positive patients have antibodies directed against GPIIb/IIIa alone, or in combination with other glycoprotein targets. Our objective was to determine the specificities of the anti-platelet antibodies in CSS patients. The detection of anti-platelet antibodies was performed using a commercially available ELISA, the Pak-AUTO (GTI, Brookfield, WI), in which highly purified GPIIb/IIIa, GPIb/IX, and GPIa/IIa are immobilized on microtitre plates, incubated with serum or plasma, and subsequently developed with an antihuman polyclonal immunoglobulin. Of 14 CSS patients tested, 11 (79%) had anti-platelet antibodies in their serum directed toward at least one of the three major GPC, nine (82%) of which were against GPIIb/IIIa alone or in combination. Antibodies detected in the sera of ITP patients had similar specificities. No such antibodies were detected in samples from 25 consecutive normal controls. These results demonstrate that a genetically defined defect in lymphocyte apoptosis results in a humoral autoimmune response with anti-platelet specificities very similar to the common idiopathic form of autoimmune thrombocytopenia.

Novel approaches to refractory immune thrombocytopenic purpura.

Chronic immune thrombocytopenic purpura (ITP) is an organ-specific autoimmune bleeding disorder in which autoantibodies are directed against the individual's own platelets, resulting in increased Fc-mediated platelet destruction by macrophages in the reticuloendothelial system. Although ITP is primarily mediated by IgG autoantibodies, the production of these autoantibodies is regulated by the influence of T lymphocytes and antigen-presenting cells (APC). There is evidence that enhanced T-helper cell/APC interactions in patients with ITP may play an integral role in IgG antiplatelet autoantibody production. New therapies may improve platelet production, decrease platelet antibody production, and decrease monocyte function and/or B-cell and T-cell activities. Understanding these cellular immune responses in ITP may lead to the development of more specific immunoregulatory therapies for the management of this disease.

Platelets: an update on diagnosis and management of thrombocytopenic disorders.

Thrombocytopenia in the pregnant patient may result from a number of causes, most of which involve either immune-mediated platelet destruction or platelet consumption. Many of these disorders share clinical and laboratory features, making accurate diagnosis difficult. Moreover, uterine evacuation is indicated in the therapy of some disorders, while in others alternative interventions may allow the pregnancy to be carried to term. These and other issues are discussed as part of a comprehensive review of the differential diagnosis and management of thrombocytopenia in pregnancy. The term "refractory ITP" is used with reference to two distinct groups of patients: 1) patients in whom the platelet count cannot be easily increased, including those who are poorly responsive to initial single agent treatment, and 2) those with persistent thrombocytopenia despite the use of conventional therapies. An approach to management of the former group will be presented, followed by a discussion of patients with chronic refractory ITP. The latter will include presentation of new data on the role of Helicobacter pylori in ITP and whether its treatment ameliorates thrombocytopenia, as well as the use of rituximab and other modalities. Thrombotic microangiopathies such as thrombotic thrombocytopenic purpura (TTP) are rare, but life threatening causes of thrombocytopenia. Ultra-large multimers of von Willebrand factor (vWF) aggregate platelets intravascularly, and congenital or immune-mediated deficiencies of a metalloprotease that cleaves these ultra-large multimers may cause TTP. However, little information exists concerning the behavior of this protease in other physiological and pathological conditions. Levels of this protease have now been measured in healthy individuals of different ages, full-term newborns, pregnant women and a patients with variety of pathologic conditions, and these data will be reviewed herein. Heparin-induced thrombocytopenia/thrombosis (HIT/T) remains the most common antibody-mediated, drug-induced thrombocytopenic disorder, and a leading cause of morbidity and mortality. Based on clinical correlations and murine models, there is increasing evidence that antibodies to complexes between platelet factor 4 (PF4) and heparin cause HIT/T, and the molecular composition of the relevant antigen has also become better defined. However, the introduction of sensitive ELISAs to measure anti-PF4/heparin antibodies has complicated diagnosis in some settings in which the incidence of such antibodies in unaffected patients exceeds the incidence of the disease. In addition, the FDA approval of Lepirudin and Argatroban has expanded the repertoire of agents available for therapy of HIT/T and may change the approach to management of asymptomatic patients with thrombocytopenia. However, the optimal use of these drugs in commonly encountered settings remains in evolution, and a need for alternative approaches to prevention and treatment is evident.

Initial fetal platelet counts predict the response to intravenous gammaglobulin therapy in fetuses that are affected by PLA1 incompatibility.

OBJECTIVE: Fetal alloimmune thrombocytopenia is the result of maternal fetal platelet antigen incompatibility; intracranial hemorrhage is its most serious complication. Our previous studies have demonstrated an inability to accurately predict fetal platelet counts in this disorder. The goal of the present investigation was to identify factors that would predict the response of the fetal platelet count to therapy so that use of fetal blood sampling could be minimized. STUDY DESIGN: Patients who were eligible for the study were all those who (1) had alloimmune thrombocytopenia secondary to Pl(A1) (HPA-1a, Zw(A)) platelet antigen incompatibility, (2) were treated with maternally administered intravenous immunoglobulin at 1 g/kg of body weight per week, with or without low dose steroids, and (3) had percutaneous fetal blood sampling before the initiation of therapy (first fetal blood sampling) and again 3 to 7 weeks afterwards (second fetal blood sampling). RESULTS: In this retrospective review, 74 patients who were affected by alloimmune thrombocytopenia had a median platelet count of 21,000 per microliter at the first fetal blood sampling and 47,000 per microliter at the second fetal blood sampling, with a median increase in platelet count of 24,000 per microliter. Response to treatment was defined as either (1) an improvement in platelet count (the second fetal blood sampling greater than the first fetal blood sampling, and second fetal blood sampling > 20,000 per microliter) or (2) a minimal decline in platelet count (the first fetal blood sampling > or = 40,000 per microliter and the difference between the first and second fetal blood sampling < or = 10,000 per microliter). The first fetal blood sampling had prognostic value for the second fetal blood sampling (P = .0001), although the previous sibling birth platelet count and history of sibling intracranial hemorrhage did not predict the platelet count at the first or second fetal blood sampling or the change in platelet count between the samplings. When the patients were segregated to first fetal blood sampling of > 20,000 per microliter versus < or = 20,000 per microliter, the response rates for the 2 groups were 89% (33/37 patients) versus 51% (19/37 patients; P = .001). CONCLUSION: In fetal alloimmune thrombocytopenia secondary to Pl(A1) platelet antigen incompatibility, fetuses with platelet counts > 20,000 per microliter at the initiation of therapy were predicted to maintain their platelet count at the second fetal blood sampling at > 20,000 per microliter. The characteristics of the previous sibling, as previously reported, did not predict the initial fetal blood sampling, the second fetal blood sampling, or the response to treatment.

Alloimmune thrombocytopenia in the fetus and newborn.

Alloimmune thrombocytopenia is an interesting and challenging disease. Identification in the fetus and newborn by screening remains to be clarified. The primary clinical criterion for neonatal diagnosis appears to be a neonatal platelet count of <50 x 10(9)/L. Treatment of the neonate can be accomplished with intravenous immunoglobulin (IVIG) +/- steroids or with matched platelet transfusion. Cranial ultrasonography is important. Testing can be performed on the parents and requires a highly experienced laboratory. If an affected fetus is identified, based on a previous affected neonate and a homozygous father, antenatal management is needed. Studies have been completed that inform the still controversial decision. IVIG remains the basis of therapy but appears to require a higher dose (2 g/kg/week) and/or the addition of 1 mg/kg of prednisone in the highest risk cases, those with antenatal intracranial hemorrhage.

Cytokine modulation with immune gamma-globulin in peripheral blood of normal children and its implications in Kawasaki disease treatment.

Intravenous immune gamma-globulin (IVIG) is used successfully in the treatment of Kawasaki disease, with dose-dependent rapid resolution of symptoms such as fever and irritability and a decrease in ESR, WBCs, and platelets. The mode of action of IVIG in reducing this inflammatory response is not clearly understood. Recently anticytokine antibodies in IVIG have been demonstrated. Serum levels of proinflammatory cytokines have been shown to be elevated in patients with Kawasaki disease. The cytokine interleukin-6 (IL-6) is involved in the de novo production of acute-phase proteins by hepatocytes and cause thrombocytosis and fever in response to tissue injury. Patients receiving parenteral recombinant human IL-6 have dose-dependently experienced fever, malaise, chills, and acute-phase reaction. With high IL-6 concentrations, central nervous system toxicity has also been reported and IL-6 has been thought to mediate endothelial damage. We evaluated the response of stimulated blood cells of 12 normal children to IVIG in the release of the cytokines IL-6, IL-8, TNF-alpha. and IL-6 receptor (sIL-6R). The levels of cytokines IL-6, IL-8, and TNF-alpha (but not sIL-6R) in peripheral blood induced by stimulation with LPS were markedly reduced (P < 0.008) within 3 hr when incubated with IVIG compared to without IVIG. Thus we demonstrated that cells of normal children respond to IVIG in vitro by reducing cytokines such as IL-8, TNF-alpha, and IL-6 without affecting the level of receptor sIL-6R during an acute inflammatory response. We also found significantly higher IL-6 levels in children with Kawasaki disease compared to children with blood culture-negative febrile illnesses. In five children with Kawasaki disease we measured serum IL-6 before and after IVIG and assessed the clinical response to IVIG therapy. Therapy with IVIG was followed by a rapid resolution of symptoms in Kawasaki disease, with a significant decrease in serum IL-6. The attenuation of proinflammatory cytokine responses, especially IL-6, following infusions of IVIG may play an integral role in the rapid resolution of symptoms and decrease in the acute-phase proteins in children with Kawasaki disease. Cells of normal children were found to respond to the IVIG in a manner similar to that of the Kawasaki children.

Anti-HPA-3A induces severe neonatal alloimmune thrombocytopenia.

OBJECTIVE: Fetal and neonatal alloimmune thrombocytopenia (AIT) caused by feto-maternal incompatibility at the HPA-1a (PLA-1) locus is well characterized. Alloimmunization and disease caused by HPA-3a is rare. STUDY DESIGN: We conducted a retrospective analysis of all known cases of AIT caused by HPA-3a incompatibility identified at 3 major reference laboratories from 1986 to 1996. Platelet antigen typing and antibody specificity were determined by serologic evaluation. In some cases confirmatory genotyping was performed. RESULTS: Fourteen cases of anti-HPA-3a-induced AIT in 11 families were identified. Five patients had a previous affected sibling, and 2 cases were firstborn children. All patients had severe thrombocytopenia at birth (platelet count <20 x 10(9)/L). Regardless of therapy, the median time to platelet recovery was 6 days (range, 3 to 23 days). Two (15%) patients had documented intracranial hemorrhage, 1 with severe sequelae including apnea and convulsions. A literature review describing 16 additional patients corroborates the finding of severe thrombocytopenia and a significant incidence of intracranial hemorrhage caused by HPA-3a incompatibility. CONCLUSION: AIT caused by incompatibility of HPA-3a is similar in severity to disease caused by incompatibility of HPA-1a. Affected families should be appropriately counseled and considered for antenatal therapy.