Karin Mellgren

Differences in gene expression and cytokine levels between newly diagnosed and chronic pediatric ITP

Immune thrombocytopenia (ITP) is an autoimmune disease where platelets are destroyed prematurely. In the majority of children the disease resolves, but in some it becomes chronic. To investigate whether these 2 phases of the disease are molecularly similar or separate entities we performed DNA microarray analysis (GEO accession number: GSE46922) of T-cells from newly diagnosed children and children with chronic ITP. We found complete separation of the gene expression profiles between the 2 phases of the disease. Furthermore, the gene expression levels of several cytokines differed between the 2 phases of the disease. This was also reflected in plasma with increased levels of interleukin (IL)-16 and TNF-related weak inducer of apoptosis and lower levels of IL-4 in newly diagnosed compared with chronic ITP. Thus, our data indicate that chronic ITP in childhood is a separate disease entity, dissimilar in many aspects to the newly diagnosed phase.

Nitric oxide in the oxygenator sweep gas reduces platelet activation during experimental perfusion

BACKGROUNDnHemorrhage is a major complication experienced in 10% to 35% of neonates treated with extracorporeal life support (ECLS). The increased bleeding tendency is partly due to an ECLS-induced thrombocytopenia and impaired platelet function. In the present study, we evaluated the effect of nitric oxide on the ECLS-induced platelet consumption and activation.nnnMETHODSnTwo identical in vitro ECLS circuits were primed with fresh, heparin-treated human blood and circulated for 24 hours. Nitric oxide (15, 40, or 77 ppm) was added to one of the oxygenators in each pair. Eight paired experiments were performed. Platelet count, plasma beta-thromboglobulin, platelet serotonin content, plasma nitrate, plasma cyclic guanosine monophosphate, and platelet membrane glycoprotein Ib were assayed before the start and at 0.5, 1, 3, 12, and 24 hours of perfusion.nnnRESULTSnPlasma nitrate and plasma cyclic guanosine monophosphate levels were significantly higher in the nitric oxide circuits than in the control circuits (p < 0.01). Higher platelet counts (p < 0.01) and lower beta-thromboglobulin levels (p < 0.01) were observed in the nitric oxide circuits compared with the control circuits. However, no significant differences in platelet serotonin content or platelet membrane glycoprotein Ib density were noted between the circuits.nnnCONCLUSIONSnNitric oxide probably reduces platelet consumption and platelet activation during ECLS.

Translational Mini-Review Series on B cell subsets in disease. Reconstitution after haematopoietic stem cell transplantation – revelation of B cell developmental pathways and lineage phenotypes

OTHER ARTICLES PUBLISHED IN THIS MINI‐REVIEW SERIES ON B CELL SUBSETS IN DISEASE

Children and adolescents with follicular lymphoma have an excellent prognosis with either limited chemotherapy or with a “watch and wait” strategy after complete resection

Data on clinical features and outcome in pediatric follicular lymphoma (pFL) are scarce. The aim of this retrospective study including 13 EICNHL and/or i-BFM study group members was to assess clinical characteristics and course in a series of 63 pFL patients. pFL was found to be associated with male gender (3:1), older age (72xa0% ≥10xa0years old), low serum LDH levels (<500xa0U/l in 75xa0%), grade 3 histology (in 88xa0%), and limited disease (87xa0% stage I/II disease), mostly involving the peripheral lymph nodes. Forty-four out of sixty-three patients received any polychemotherapy and 1/63 rituximab only, while 17/63 underwent a “watch and wait” strategy. Of 36 stage I patients, 30 had complete resections. Only one patient relapsed; 2-year event-free survival and overall survival were 94u2009±u20095 and 100xa0%, respectively, after a median follow-up of 2.2xa0years. Conclusively, treatment outcome in pFL seems to be excellent with risk-adapted chemotherapy or after complete resection and an observational strategy only.

Plasma cytokine profiles at diagnosis in pediatric patients with non-hodgkin lymphoma.

Non-Hodgkin lymphoma (NHL) has been associated with elevated levels of inflammatory and immune-regulating cytokines, and polymorphisms in the genes encoding interleukin (IL)-10 and tumor necrosis factor (TNF)-&agr; have been associated with increased incidence of certain subtypes of NHL. The aim of the present study was to screen for a broader spectrum of growth factors and inflammatory mediators and to compare the profiles in different subtypes of NHL in pediatric patients. Serum samples were collected at diagnosis from 31 pediatric patients diagnosed with NHL admitted at Rigshospitalet, Copenhagen, between 1995 and 2008. Cytokines and growth factors were measured in serum using the Luminex platform by application of a 30-plex kit. Levels of IL-6, IL-2R, IL-10, TNF-RI, and macrophage inflammatory protein-1&agr; were significantly higher in patients with anaplastic large-cell lymphoma compared with patients diagnosed with B-cell lymphomas and lymphoblastic lymphomas. High levels of IL-4, IL-13, TNF-RI, and epidermal growth factor were associated with a poorer general condition at diagnosis. The present study suggests that NHL subgrouping and the general condition of pediatric patients at diagnosis are associated with plasma levels of growth factors and inflammatory mediators at presentation.

Patterns of psychological responses in parents of children that underwent stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) is curative in several life‐threatening pediatric diseases but may affect children and their families inducing depression, anxiety, burnout symptoms, and post‐traumatic stress symptoms, as well as post‐traumatic growth (PTG). The aim of this study was to investigate the co‐occurrence of different aspects of such responses in parents of children that had undergone HSCT.

Relationship between problems related to child late effects and parent burnout after pediatric hematopoietic stem cell transplantation

A few studies have indicated that parents reactions to a childs serious disease may entail long‐term stress for the parents. However, further knowledge of its consequences is valuable. The aim of the study was to investigate the occurrence of burnout in a Swedish national sample of parents of children who had undergone HSCT and survived. Burnout (Shirom–Melamed Burnout Questionnaire) and estimations of the childs health status (Lansky/Karnofsky estimations and study‐specific questions) were self‐reported by 159 mothers and 123 fathers. In addition, physicians made estimations of the childs health status (Lansky/Karnofsky estimations). Nonparametric tests revealed that burnout symptoms occurred more often among fathers of children who had undergone transplantation within the last five yr compared to fathers of children with no history of serious disease (34.4% vs. 19.9%). Burnout among mothers and fathers was associated with the childs number and severity of health impairments up to five yr after the child underwent HSCT (Spearmans rho for mothers 0.26–0.36 and for fathers 0.36–0.61). In conclusion, chronic stress in parents after a childs HSCT seems to abate eventually. However, parents should be monitored and offered adequate support when needed. Moreover, the situation of fathers in the often mother‐dominated pediatric setting should receive more attention in research as well as in the clinic.

The effect of albumin priming solution on platelet activation during experimental long-term perfusion.

The objective of this study was to evaluate the effect of albumin priming on platelet consumption and activation during long-term perfusion. Two identical in vitro extracorporeal membrane oxygenation circuits were used; one was primed with Ringer’s solution containing human serum albumin, the other with Ringer’s solution only. Fresh heparinized human blood was pooled, divided between the two systems and circulated for 24 h at 37°C. Platelet count, plasma concentration of betathromboglobulin (BTG), platelet membrane density of glycoprotein (GP) Ib and of GPIIb/IIIa were assayed before the start and at 0.5, 1, 3, 12 and 24 h of perfusion. In total, seven experiments were performed. We found that during the first hour of perfusion, slightly higher platelet counts (p = 0.058) and lower BTG values (p = 0.0005) were observed in the circuits primed with albumin, compared to the control circuits. No statistically significant differences were observed for the platelet membrane expression of GPIb and GPIIb/IIIa. We conclude that albumin priming appears to transiently prevent platelet consumption and activation during long-term perfusion.

Influence of hemofiltration on plasma cytokine levels and platelet activation during extra corporeal membrane oxygenation.

OBJECTIVEnExtra corporeal circulation of human blood is used daily in lifesaving procedures such as open-heart surgery and extracorporeal membrane oxygenation (ECMO). But extracorporeal circulation also induces activation of various cascade reactions in the blood. The objective of this study was to evaluate the effects of hemofiltration on cytokine release and removal as well as on platelet activation and consumption.nnnMATERIAL AND METHODSnTwo complete ECMO systems, each of them holding a hollow fiber oxygenator, a bladder box, PVC tubing and a roller pump were perfused for 24 h with fresh, heparinized human blood. A hemofilter was added to one of the paired systems. Blood samples were collected from both circuits before start, and at 0.5, 1, 3, 12 and 24 h of perfusion. A total of 8 paired experiments was performed.nnnRESULTSnThe plasma concentration of interleukin (IL)1beta, IL-6 and IL-8, as well as of IL-1 receptor antagonist (IL-1ra) increased over time in both systems, but consistently lower levels were observed in the filter circuits compared to the controls. Only minor parts of these cytokines could be assayed in the ultrafiltrate. No significant difference in platelet count and platelet membrane expression of glycoprotein Ib was observed between the circuits.nnnCONCLUSIONSnBy adding a hemofilter to the ECMO circuit, it is possible to reduce the plasma concentration of interleukins without significantly affecting platelet activation and consumption.

Opportunistic virus DNA levels after pediatric stem cell transplantation: serostatus matching, anti-thymocyte globulin, and total body irradiation are additive risk factors

C. Kullberg‐Lindh, K. Mellgren, V. Friman, A. Fasth, H. Ascher, S. Nilsson, M. Lindh. Opportunistic virus DNA levels after pediatric stem cell transplantation: serostatus matching, anti‐thymocyte globulin, and total body irradiation are additive risk factors.u2028Transpl Infect Dis 2011: 13: 122–130. All rights reserved