Sylwia Kołtan

Hematopoietic stem cell transplant in patients with activated PI3K delta syndrome.

Zohreh Nademi, PhD, Mary A. Slatter, MD, Christopher C. Dvorak, MD, Benedicte Neven, MD, Alain Fischer, MD, Felipe Suarez, MD, Claire Booth, MD, Kanchan Rao, MD, Alexandra Laberko, MD, Julia Rodina, MD, Yves Bertrand, MD, Sylwia Kołtan, MD, Robert Dębski, MD, Terence Flood, MD, Mario Abinun, MD, Andrew R. Gennery, MD, Sophie Hambleton, DPhil, Stephan Ehl, MD, Andrew J. Cant, MD, on behalf of the Inborn Errors Working Party of EBMT and ESID

Epidemiologic aspects and preventive strategy of hepatitis B and C viral infections in children with cancer.

AIMS We present the efficacy of a strategy to control infections with hepatitis B (HBV) and C viruses (HCV) in children with cancer and assessment of risk for their relatives and health care personnel. A total of 1242 people entered the study, including 558 children with cancer, 193 relatives of infected children, 302 health care workers and 189 controls. METHODS To stop dual HBV and HCV nosocomial infection in the oncology department, a preventive strategy was introduced. It involved immunoprophylaxis against HBV, screening blood donors for HCV infection, intensification of nonspecific prophylaxis, an educational program and estimation of risk for relatives of infected children and health care personnel. RESULTS Retrospective analysis showed that the prevalence of HBV and HCV infections in children with cancer was 74 of 119 (62.2%) and 50 of 92 (54.3%), respectively, with the highest rate among patients with leukemia. Inferior anticancer therapeutic response were obtained in infected children. Specific anti-HBV immunoprophylaxis introduced simultaneously with anticancer therapy resulted in protection of 160 of 168 (95.2%) children in the first 4 years, when 62.9% of patients receiving therapy developed protective antibodies. Screening of blood donors and intensification of nonspecific prophylaxis reduced HCV prevalence to 2.8% during the most recent 1.5 years. Genotype analysis showed that the risk of HCV infection was 0.5% for relatives of infected children. The risk for health care personnel was 0 in the oncology ward and 1.9% in the other departments, and it reached 0.53% in control group. CONCLUSIONS The preventive strategy of viral hepatitis in children with cancer, including passive-active HBV immunoprophylaxis from the beginning of chemotherapy and intensive nonspecific prophylactic measures is effective. With this strategy the risk of intrafamily and occupational infection is low.

Improvement of cure after hematopoietic stem cel transplantations in children

Wstep. Transplantacja komorek krwiotworczych (HSCT) jest wazną metodą terapeutyczną w wielu wrodzonych i nabytych chorobach, w tym nowotworowych, zespolach niewydolności szpiku oraz zaburzeniach immunologicznych i metabolicznych. Celem pracy jest analiza wynikow HSCT w pojedynczym ośrodku pediatrycznym w okresie 12 lat. Pacjenci i metodyka. Analizie poddano wyniki przeszczepien wykonanych w latach 2003-2015 w Klinice Pediatrii, Hematologii i Onkologii w Bydgoszczy. Transplantacje analizowano w trzech przedzialach czasowych: 2004-2007, 2008-2011 oraz 2012-2015. Wyniki. Wykonano 318 HSCT, w tym 186 alloge-nicznych (68 zgodnych rodzinnych i 118 od dawcow alternatywnych) oraz 132 autologiczne. Średnie przezycie po HSCT, wyznaczone metodą Kaplana-Meiera wynioslo 8,1 lat. Calkowite prawdopodobienstwo przezycia (pOS) wynioslo 0,64±0,03; pOS po allo-HSCT wynosi 0,62±0,04, a po auto-HSCT 0,67±0,05. Nie wykazano znamiennych roznic w pOS zarowno po allo-HSCT, jak i po auto-HSCT pomiedzy drugim (2008-2011) i trzecim (2012-2015) analizowanym okresie. Jednakze, pOS bylo wyzsze w dru-gim i trzecim okresie w stosunku do okresu pierwszego (2004-2007), zarowno dla wszystkich pacjentow, jak i u pacjentow po auto-HSCT. W grupie pacjentow allo-HSCT, uzyskano wzrost pOS o ponad 20% (43% vs 66% vs 64% w kolejnych przedzialach czasu; ns). Wnioski. Wyniki HSCT uzyskiwane aktualnie w na-szym ośrodku są porownywalne z wynikami podawanymi w miedzynarodowych rejestrach.

Phenotype of NK Cells Determined on the Basis of Selected Immunological Parameters in Children Treated due to Acute Lymphoblastic Leukemia.

AbstractAcute lymphoblastic leukemia (ALL) is the most frequent pediatric malignancy. The chemotherapy for ALL is associated with a profound secondary immune deficiency.We evaluated the number and phenotype of natural killer (NK) cells at diagnosis, after the intensive chemotherapy and following the completion of the entire treatment for patients with ALL. The fraction, absolute number, and percentage of NK cells expressing interferon-&ggr; were determined in full blood samples. The fraction of NK cells expressing CD158a, CD158b, perforin, A, B, and K granzymes was examined in isolated NK cells.We have shown that patients assessed at ALL diagnosis showed significantly lower values of the fraction of NK cells and percentage of NK cells with the granzyme A expression. Additionally, the absolute number of NK cells, the expression of CD158a, CD158b, perforin, and granzyme A were significantly lower in patients who completed intensive chemotherapy. Also, there was a significantly higher fraction of NK cells expressing granzyme K in patients who completed the therapy.Abnormalities of NK cells were found at all stages of the treatment; however, the most pronounced changes were found at the end of intensive chemotherapy.

Thiopurine methyltransferase activity in children with acute myeloid leukemia

Activity of the enzyme thiopurine methyltransferase (TPMT) determines the anti-leukemic effect of thiopurines used in the chemotherapy of acute lymphoblastic leukemia (ALL) and acute myeloblastic leukemia (AML). TPMT status and its effects on treatment outcome have been studied extensively in ALL and autoimmune disorders, but few data is available on TPMT in AML. The present study assessed the genetic polymorphisms and activity of TPMT in children with AML at different treatment stages, and compared the results with those obtained for children with ALL. The study included 33 children with AML (0.7-19.7 years) treated with 6-thioguanine (6-TG) according to the AML-BFM 2004 Protocol. Blood samples were collected at diagnosis, during and following maintenance chemotherapy from 8, 10 and 17 patients with AML (the assay was performed at two time points in 2 patients), respectively. Blood samples from 105 children with ALL were obtained at diagnosis, during the maintenance chemotherapy and following the cessation of the chemotherapy from 16, 55 and 34 children, respectively. The activity of TPMT in red blood cells lysates was measured using an enzymatic reaction based on the conversion of 6-mercaptopurine into 6-methylmercaptopurine, involving S-adenozyl-L-methionine as the methyl group donor. TPMT mutations were determined using a polymerase chain reaction/restriction fragment length polymorphism method. Median TPMT activity at diagnosis, during maintenance chemotherapy and following chemotherapy was 43.1, 47,3 and 41.7 nmol 6-mMP g-1 Hb h-1, respectively. All patients with AML exhibited the homozygous TPMT*1/*1 genotype, with the exception of 1, who was a heterozygote with the TPMT*1/*3C genotype and demonstrated a TPMT activity level at diagnosis of 42.5 nmol 6-mMP g-1 Hb h-1. At each chemotherapy stage, the median TPMT activities in children with AML were significantly increased compared with the median TPMT activities in children with ALL. The preliminary results suggest that the TPMT activity in AML may be increased compared with that in ALL. Comprehensive studies on the association between thiopurine metabolism and treatment outcome in AML are required, with regard to the cytogenetic and molecular factors currently used for AML risk stratification.

2,4,6‑Trimethyl‑N‑[3‑(trifluoromethyl)phenyl]benzenesulfonamide increases calcium influx in lipopolisaccharide-pre-treated arteries

It has been demonstrated that 2,4,6-trimethyl-N-[3-(trifluoromethyl)phenyl]benzenesulfonamide (m-3M3FBS) activates phospholipase C (PLC) and stimulates apoptosis in smooth muscle cells, which may increase vascular reactivity. The primary aim of the present study was to evaluate the physiological effects of the direct stimulation of PLC by m-3M3FBS on vascular smooth muscle reactivity in arteries pre-treated with lipopolysaccharides (LPS) as a model of septic shock. Experiments were performed on isolated and perfused tail arteries of Wistar rats. The contraction force in the model was measured by assessing increases in perfusion pressure at a constant flow. Parameters describing the concentration-response curves (CRCs) obtained for phenylephrine and arginine-vasopressin in the presence of LPS confirmed a decrease in vessels reactivity. In comparison with the controls, m-3M3FBS treatment caused a significant increase in LPS-untreated as well as pre-treated arteries. Furthermore, in the presence of m-3M3FBS, calcium influx from intra- as well as extracellular calcium stores was significantly higher for LPS-untreated and pre-treated arteries. The results of the present study suggested that m-3M3FBS significantly increased the reactivity of vascular smooth muscle cells pre-treated with LPS by increasing the calcium influx from intra- and extracellular calcium stores. Further studies investigating this mechanism are required to evaluate whether this pathway may be a potential therapeutic strategy to treat sepsis.

EFFECT OF PHOSPHOLIPASE C INHIBITION ON VASCULAR SMOOTH MUSCLE CONTRACTION

Phospholipase C is the key enzyme responsible for the hydrolysis of membrane phospholipids phosphatidylinositol 4,5-bisphosphate (PIP 2 ) to two intracellular transmitters - diacylglycerol (DAG) and inositol triphosphate (IP 3 ). PLC activation of smooth muscle leads to an increase in the concentration of IP 3 and DAG which initiates the increase in the concentration of calcium ions into the cytoplasm as a result of the flow from the intracellular and then from extracellular pool. Main aim of this study was to evaluate the effect of PLC inhibitor U-73122 on vascular smooth muscle contraction stimulated pharmacologically with phenylephrine (PHE, α 1 -adrenoceptor agonist) and arg-vasopressin (AVP, vasopressin receptor agonist). Material and methods. Experiments were performed on isolated and perfused tail artery of Wistar rats. Contraction force in our model was measured by increased level of perfusion pressure with a constant flow. Results. Reactivity of vascular smooth muscle cells to PHE (10 -9 - 10 -3 M/L), and AVP (10 -10 – 10 -4 M/L), in the control group and in the presence of U-73122 – phospholipase C inhibitor at concentrations 1, 3 and 10 μM/l was analyzed. EC 50 values calculated for PHE and AVP were 7.52 (±0.97) x10 -8 M/L and 1.84 (±0.6) x10 -8 M/L, respectively. The concentration-response curves obtained for PHE and AVP in the presence of U-73122 were shifted to the rightward with a decrease in maximal responses. In the presence of U-73122 the significant and dose dependent reduction in perfusion pressure was found for both agonists for calcium influx from intracellular calcium stores and from extracellular space. Conclusion. Results of our experiments suggest that in the presence of phospholipase C inhibitors, contraction induced by G-protein coupled receptors activation may by effectively inhibited by reduction in calcium influx from intra and extracellular calcium stores.

Zespół Wiskotta i Aldricha – rzadka przyczyna małopłytkowości u niemowląt – opis dwóch przypadków☆☆☆

Maloplytkowośc stosunkowo rzadko wystepuje u niemowląt. Moze byc objawem chorob wrodzonych lub nabytych, najcześciej jednak ma charakter przemijający. Rzadką przyczyną maloplytkowości jest genetycznie uwarunkowany, najcześciej sprzezony z chromosomem X, zespol Wiskotta i Aldricha (WAS). Maloplytkowośc rozpoznano u 38 spośrod 1397 hospitalizowanych niemowląt. U 29 dzieci stwierdzono ostrą skaze maloplytkową, towarzyszącą infekcjom lub samoistną, u 5 maloplytkowośc byla objawem ostrej bialaczki, u 1 dziecka ciezkiej anemii aplastycznej, i u 1 zespolu Shwachmana i Diamonda. U 2 chlopcow rozpoznano zespol Wiskotta i Aldricha. W obydwu przypadkach wywiad rodzinny byl ujemny, maloplytkowośc z obnizoną objetością plytek obserwowano od wczesnego okresu niemowlecego, nasilające sie z wiekiem zmiany o charakterze alergicznego zapalenia skory oraz infekcje wirusowe i bakteryjne jako przejaw niedoboru odporności. Ze wzgledu na fenotyp wysunieto podejrzenie WAS, ktory potwierdzono badaniem molekularnym odpowiednio w 7 i 4 miesiącu zycia.