Acquired thrombotic thrombocytopenic purpura in children: a single institution experience.

OBJECTIVE: To describe the clinical features, treatment and prognosis of acquired thrombotic thrombocytopenic purpura (TTP) in children based on a single institution experience. METHODS: This study is a retrospective review of all 12 children with TTP seen at New York Medical College- Westchester Medical Center during a period of 15 y from 1993 to 2008. RESULTS: There were 7 females and 5 males with acquired TTP, with a median age of 13 (range, 6-17); and no cases of congenital TTP. The classic pentad of TTP (microangiopathic hemolytic anemia, thrombocytopenia, neurologic symptoms, renal dysfunction and fever) was seen in only three patients. Nine had renal involvement; eight had neurologic symptoms; and four had fever. All 12 patients had thrombocytopenia, anemia, and elevated LDH. Nine had idiopathic TTP. Three patients had one of the following underlying disorders: systemic lupus erythematosus, mixed connective tissue disorder, and aplastic anemia (post-bone marrow transplant on cyclosporine). ADAMTS13 level was decreased in 7 of 8 patients studied. Eight of 10 patients achieved remission with plasmapheresis alone. Two needed additional treatment before achieving remission. Two had one or more relapses, requiring immunosupressive treatment with vincrisine, prednisone, or rituximab. The patient with aplastic anemia died of pulmonary hypertension 5 y after bone marrow transplantation. All other 11 patients are alive and free of TTP for a median follow-up of 12 mo (range, 3-72 mo). CONCLUSIONS: Acquired pediatric TTP responds well to plasmapheresis. However, many patients do require additional treatment because of refractoriness to plasmapheresis or relapse. The clinical features, response to treatment, and relapse rate of pediatric TTP appear similar to those of adult TTP.

Hemophagocytic lymphohistiocytosis associated with necrotizing enterocolitis in premature newborns.

Hemophagocytic lymphohistiocytosis (HLH) is a systemic disease resulting from the excessive release of inflammatory cytokines by macrophages under prolonged antigenic stimulation. If untreated, it leads to multiorgan failure and death. Necrotizing enterocolitis (NEC) has not previously been associated with HLH. Here we report four preterm infants who were diagnosed with HLH associated with NEC. Two patients received chemotherapy and one survived. The other two infants succumbed to multiorgan failure. These results suggest that NEC may be a common clinical manifestation of HLH in premature neonates.

DNA damage response as a biomarker in treatment of leukemias.

Early assessment of cancer response to the treatment is of great importance in clinical oncology. Most antitumor drugs, among them DNA topoisomerase (topo) inhibitors, target nuclear DNA. The aim of the present study was to explore feasibility of the assessment of DNA damage response (DDR) as potential biomarker, eventually related to the clinical response, during treatment of human leukemias. We have measured DDR as reported by activation of ATM through its phosphorylation on Ser 1981 (ATM-S1981(P)) concurrent with histone H2AX phosphorylation on Ser139 (gammaH2AX) in leukemic blast cells from the blood of twenty patients, 16 children/adolescents and 4 adults, diagnosed with acute leukemias and treated with topo2 inhibitors doxorubicin, daunomycin, mitoxantrone or idarubicin. Phosphorylation of H2AX and ATM was detected using phospho-specific Abs and measured in individual cells by flow cytometry. The increase in the level of ATM-S1981(P) and gammaH2AX, varying in extent between the patients, was observed in blasts from the blood collected one hour after completion of the drug infusion with respect to the pre-treatment level. A modest degree of correlation was observed between the induction of ATM activation and H2AX phosphorylation in blasts of individual patients. The number of the studied patients (20) and the number of the clinically non-responding ones (2) was too low to draw a conclusion whether the assessment of DDR can be clinically prognostic. The present findings, however, demonstrate the feasibility of assessment of DDR during the treatment of leukemias with drugs targeting DNA.

Recurrent immune thrombocytopenic purpura in children.

Recurrent immune thrombocytopenic purpura (ITP) is defined as the recurrence of ITP after at least 3 months of remission sustained without treatment. Among 340 children with ITP, 14 had recurrent ITP (4.1%). Ten were females. The initial course was acute in 8 patients and chronic in 6. The median time to recurrence was 33 months (range 4-120). Only 1 patient had a second recurrence. Twelve (86%) achieved complete (n = 10) or partial (n = 2) remission, two of them after splenectomy. One patient continued to require treatment at 10 months from recurrence. One child died of intracranial hemorrhage despite aggressive treatment including splenectomy and craniotomy.

GATA1 as a new target to detect minimal residual disease in both transient leukemia and megakaryoblastic leukemia of Down syndrome.

Acquired mutations in exon 2 of the GATA1 gene are detected in most Down syndrome (DS) patients with transient leukemia (TL) and acute megakaryoblastic leukemia (AMKL). We sought to determine if GATA1 mutations can be utilized as markers for minimal residual disease (MRD). GATA1 mutations were screened by SSCP analysis and sequenced. Using GATA1 mutation-specific primers, follow-up bone marrow samples from four patients were assayed by quantitative PCR. We show that molecular monitoring of GATA1 mutations is possible in Down syndrome patients with TL and AMKL, and GATA1 could be a stable marker for MRD monitoring.

Detection of central nervous system leukemia in children with acute lymphoblastic leukemia by real-time polymerase chain reaction.

Accurate detection of central nervous system (CNS) involvement in children with newly diagnosed acute lymphoblastic leukemia (ALL) could have profound prognostic and therapeutic implications. We examined various cerebrospinal fluid (CSF) preservation methods to yield adequate DNA stability for polymerase chain reaction (PCR) analysis and developed a quantitative real-time PCR assay to detect occult CNS leukemia. Sixty CSF specimens were maintained in several storage conditions for varying amounts of time, and we found that preserving CSF in 1:1 serum-free RPMI tissue culture medium offers the best stability of DNA for PCR analysis. Sixty CSF samples (30 at diagnosis and 30 at the end of induction therapy) from 30 children with ALL were tested for CNS leukemic involvement by real-time PCR using patient-specific antigen receptor gene rearrangement primers. Six of thirty patient diagnosis samples were PCR-positive at levels ranging from 0.5 to 66% leukemic blasts in the CSF. Four of these patients had no clinical or cytomorphological evidence of CNS leukemia involvement at that time. All 30 CSF samples drawn at the end of induction therapy were PCR-negative. The data indicate that real-time PCR analysis of CSF is an excellent tool to assess occult CNS leukemia involvement in patients with ALL and can possibly be used to refine CNS status classification.

Long-term outcome of chronic idiopathic thrombocytopenic purpura in children.

OBJECTIVES: Children with chronic idiopathic thrombocytopenic purpura (ITP) generally have a favorable outcome, but it is not known whether there are any prognostic factors to predict outcome. The objectives of this study were to assess the spontaneous remission rate and the prognostic significance of age, gender, initial platelet count, initial treatment, and response to treatment. METHODS: In this retrospective review of 62 consecutive children with chronic ITP, 37 were girls and 27 were 10 years of age or older (median age 9 years; range, 0.75-19). RESULTS: Thirty-five patients (56%) achieved spontaneous remission (remission without splenectomy), 30 of them (48%) within 4 years from diagnosis. Twenty-eight (45%) were complete remissions (platelet counts of >/=100,000) and 7 (11%) were partial remissions (50,000-99,000). There was no significant difference in the spontaneous remission rate between the younger (<10 years) and older children (55.8% vs. 57.1%, P = 0.95) or between boys and girls (56% vs. 56.7%, P = 0.98). Similarly, platelet count at initial diagnosis, initial therapy, or response to initial therapy did not have any prognostic significance. All 14 patients who underwent splenectomy achieved complete remission. CONCLUSIONS: More than 50% of children with chronic ITP achieve spontaneous remission. Age, gender, platelet count at initial diagnosis, initial treatment, and response to initial treatment do not have any prognostic significance toward the outcome of chronic ITP.

A pilot trial of tandem autologous peripheral blood progenitor cell transplantation following high-dose thiotepa and carboplatin in children with poor-risk central nervous system tumors.

This is a pilot study performed to determine the maximum tolerated number of courses of high-dose thiotepa and carboplatin with autologous peripheral blood progenitor cell (PBPC) transplantation in poor-risk pediatric central nervous system (CNS) tumor patients. Twelve patients were enrolled and a total of 24 PBPC transplants were performed. The median age was 7.7 years. All patients had CNS tumors: 4 relapsed CNS PNET, 2 high-risk PNET in first remission, 2 relapsed/progressive brainstem tumor, 2 relapsed/progressive anaplastic astrocytoma, 1 relapsed GBM, and 1 recurrent ependymoma. The regimen consisted of thiotepa 250 mg/m2/day x 3 days and carboplatin 400 mg/m2/day x 3 days. No toxic deaths occurred. All patients were hospitalized for a median duration of 17 days. The median number of CD34 cells infused was 5.4 x 10(6)/kg (2.1-29.7 x 10(6)/kg) per course. Median time to ANC > 0.5 x 10(9)/L was 9 days, and platelets > 20 x 10(9)/L was 13.5 days. Four patients came off protocol after only one course of PBPC (2 had tumor progression, 2 parental choice); 4 patients underwent two, and 4 patients three courses of PBPC. Major nonhematologic complications were mucositis that necessitated infusion of narcotics (11/24 courses), fever of unknown origin (12/24), documented infection (9/24), and hemorrhagic cystitis (3/24). TPN was administered during 22 of 24 courses with a median duration of 15 days. It isfeasible to administer 2-3 courses of tandem high-dose thiotepa and carboplatin with PBPC transplant with prompt engraftment and manageable toxicities in pediatric CNS tumor patients.

Use of vincristine and cyclosporine in childhood thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura (TTP) is a rare but life-threatening hematologic disorder in children. Plasmapheresis, the standard therapy for TTP, is effective in achieving remission in most patients. However, some patients become either refractory to or dependent upon plasmapheresis. The authors report three such patients in whom the use of vincristine or vincristine plus cyclosporine resulted in permanent remission. A 12-year-old girl with TTP dependent on plasmapheresis for more than 5 months responded to vincristine with a decrease in the required frequency of plasmapheresis, but the addition of cyclosporine abrogated the need for further plasmapheresis. She subsequently developed serologic evidence of systemic lupus erythematosus. Two 15-year-old boys with TTP (one of them with underlying mixed connective tissue disease) became refractory to plasmapheresis after a brief initial response. The addition of vincristine in one patient and vincristine and cyclosporine in the second (with mixed connective tissue disease) led to complete remission. The authors' experience in this case study of three patients suggests that vincristine and cyclosporine are effective agents in the management of patients with TTP who do not achieve complete remission with plasmapheresis alone.

Real-time quantitative PCR: standardized detection of minimal residual disease in pediatric acute lymphoblastic leukemia. Polymerase chain reaction.

PURPOSE: To develop a standardized real-time polymerase chain reaction (PCR) method of quantifying minimal residual disease (MRD) in patients with pre-B acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: In a series of 24 follow-up bone marrow (BM) samples in 11 patients (14 clonal markers), we performed real-time PCR assays using one consensus and one clone-specific primer for each marker. The markers analyzed included immunoglobulin heavy chain (IgH), T-cell receptor (TCR) and TEL-AML1 rearrangements. RESULTS: We achieved a detection limit of 3.3 x 10(-5) +/- 1.2 x 10(-5) and an accurate quantitation (r = -0.99) limit of 2.0 x 10(-4) +/- 8.8 x 10(-5) blasts. Both inter- and intra-assay reproducibility were exceptional. Additionally, we found comparable results to those of a "gold standard" limiting-dilution PCR assay (r = 0.62). CONCLUSIONS: The IgH, TCR and TEL-AML1 markers can be used as targets by real-time PCR under the same cycling profile, allowing quantitation of MRD in more 95% of patients with pre-B ALL. This standardized, real-time PCR technique should simplify monitoring MRD in clinical trials.

Primary renal lymphoma and hypercalcemia in a child.

Renal lymphoma is most frequently due to secondary lymphomatous infiltration of the kidneys in advanced stage disease. Rarely, are the kidneys the tissue of origin. We describe a 15-year-old male presenting with hypercalcemia and acute renal failure, due to a bilateral "primary B-cell lymphoma of the kidneys". The diagnosis was established by percutaneous needle biopsy of the right kidney. His disease was metastatic to multiple bones. His presenting features radiological findings and biopsy results are unique. We report his case, and review the pediatric literature.

Hemophagocytic lymphohistiocytosis presenting with thrombocytopenia in the newborn.

Hemophagocytic lymphohistiocytosis (HLH) may present with thrombocytopenia during the newborn period. Three neonates (one term and two preterm) presented during the newborn period with thrombocytopenia. Transient recovery occurred in two newborns. The diagnosis of HLH was made after the recurrence of thrombocytopenia and the clinical symptoms at 5 and 7 weeks. The third infant was a premature baby diagnosed at 8 days of age after manifesting the clinical and laboratory features of HLH. All three neonates were treated with chemotherapy and responded well. After hematologic and clinical remission was achieved, the two newborns received hematopoietic stem cell transplantation from allogeneic donors. The third neonate is currently receiving chemotherapy. Persistent or recurrent thrombocytopenia of undetermined cause during the neonatal period should raise the suspicion of HLH, even though other symptoms or signs are not yet evident.