Renee V. Gardner

Long-term safety and efficacy of deferasirox (Exjade®) for up to 5 years in transfusional iron-overloaded patients with sickle cell disease

To date, there is a lack of long‐term safety and efficacy data for iron chelation therapy in transfusion‐dependent patients with sickle cell disease (SCD). To evaluate the long‐term safety and efficacy of deferasirox (a once‐daily oral iron chelator), patients with SCD completing a 1‐year, Phase II, randomized, deferoxamine (DFO)‐controlled study entered a 4‐year extension, continuing to receive deferasirox, or switching from DFO to deferasirox. Average actual deferasirox dose was 19·4 ± 6·3 mg/kg per d. Of 185 patients who received at least one deferasirox dose, 33·5% completed the 5‐year study. The most common reasons for discontinuation were withdrawal of consent (23·8%), lost to follow‐up (9·2%) and adverse events (AEs) (7·6%). Investigator‐assessed drug‐related AEs were predominantly gastrointestinal [including nausea (14·6%), diarrhoea (10·8%)], mild‐to‐moderate and transient in nature. Creatinine clearance remained within the normal range throughout the study. Despite conservative initial dosing, serum ferritin levels in patients with ≥4 years deferasirox exposure significantly decreased by −591 μg/l (95% confidence intervals, −1411, −280 μg/l; P = 0·027; n = 67). Long‐term deferasirox treatment for up to 5 years had a clinically acceptable safety profile, including maintenance of normal renal function, in patients with SCD. Iron burden was substantially reduced with appropriate dosing in patients treated for at least 4 years.

Use of 2-chlorodeoxyadenosine to treat infantile myofibromatosis.

A 3-year-old boy had fever and bone pain. Magnetic resonance imaging of his femurs showed marrow replacement; iliac crest marrow biopsy revealed myelofibrosis. Although the pathologic criteria for Langerhans cell histiocytosis were not met, the clinical picture led to treatment with etoposide and methylprednisolone, without clinical improvement. One month after presentation, generalized tonic-clonic seizures occurred, and magnetic resonance imaging revealed parenchymal brain lesions. 2-chlorodeoxyadenosine was used. Because of the unexpected lack of response to etoposide and methylprednisolone, a second bone biopsy was performed. The diagnosis was revised to infantile myofibromatosis. After six courses of 2-chlorodeoxyadenosine, brain and bone lesions regressed, with resolution of the clinical symptoms.

Metastatic perivascular epithelioid cell tumor of the colon in a child.

Painless hematochezia in a school-age child is the hallmark of a juvenile colorectal polyp. Rarely do malignant gastrointestinal (GI) neoplasms present with painless rectal bleeding in childhood. We describe the clinical and pathological features of a PEComa of the sigmoid colon with regional metastases in an 11-year-old boy with painless hematochezia and mild anemia. The PEComa is a recently described tumor of unknown cellular origin and low-grade malignancy characterized by both smooth muscle and melanocytic differentiation. Most cases affect adult women, and most tumors are found in the uterus (1). To the best of our knowledge, this is the first report of a metastatic PEComa involving the GI tract of a child.

Iron deficiency reduces serum and in vitro secretion of interleukin-4 in mice independent of altered spleen cell proliferation.

Iron deficiency, a worldwide public health problem in children and adult women, impairs innate and cell-mediated immunity including interferon-γ secretion. Its effects on interleukin (IL)-4 have not been well investigated. Interleukin-4, a cytokine primarily secreted by TH2 lymphocytes, regulates B-cell proliferation and the switching of immunoglobulin (Ig)M to IgE subtypes; the latter is involved in the defense against helminth infection. Considering the fact that interferon-γ is a potent inhibitor of IL-4, we hypothesize that iron deficiency would increase the secretion of IL-4 and IgE. We measured IL-4 in serum and supernatant of concanavalin A and anti-CD3 antibody-treated spleen cells from iron-deficient, control, pair-fed DBA and C57BL/6 mice (20-24/group) and iron-replete mice for 3, 7, and 14 days (8-13/group). Feeding the low-iron diet (5 ppm vs 50 ppm for the control diet) for 2 months significantly reduced the mean levels of hemoglobin, hematocrit, liver iron stores, thymus weight, and induced splenomegaly in both strains of mice (P < .001). Iron deficiency, and not pair-feeding, reduced plasma IL-4 levels (P < .05), although it did not significantly affect IgE levels. Iron deficiency, especially when associated with thymus atrophy, reduced in vitro IL-4 secretion by activated spleen cells, cell proliferation, and percentage of CD4⁺IL-4⁺ cells (P < .05). Impaired cell proliferation did not fully explain reduced in vitro IL-4 secretion because iron-deficient mice with a normal thymus weight had a normal (3)H-thymidine uptake but decreased supernatant IL-4. It was likely due to low percentage of CD4⁺IL-4⁺. Iron repletion improved IL-4 measurements. Data suggest that iron deficiency has generalized negative effects on T-cell function. Unaltered plasma IgE may be due to other cytokines (ie, IL-13) that also modulate its secretion.

The effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on primitive hematopoietic stem cell (PHSC) function and numbers, after chemotherapy

OBJECTIVE Primitive hematopoietic stem cell function was assessed after cyclophosphamide with granulocyte-macrophage colony-stimulating factor (GM-CSF), with or without preadministration of interleukin-1, using competitive repopulation. METHODS C57B6/J mice injected with one or four biweekly intravenous injections of cyclophosphamide, 200 mg/kg, received granulocyte-macrophage colony-stimulating factor, 1 microg, subcutaneously for 5 days, beginning 24 hours after cyclophosphamide. Alternatively, mice were injected with interleukin-1, 1 microg, 20 hours before administration of drug or drug and cytokine. Marrow obtained from mice sacrificed 4 weeks after the last dose of drug or drug and cytokine was used in competitive repopulation. RESULTS Significant reductions in marrow repopulating ability occurred after a single dose of cyclophosphamide or multiple injections. Repopulating units (RU) were calculated, and both binomial and Poisson models for estimation of primitive hematopoietic stem cell (PHSC) numbers were used. RU were significantly diminished for all treatment groups when compared to controls. PHSC numbers were not significantly affected by either regimen of cyclophosphamide given alone. Addition of GM-CSF to cyclophosphamide, whether the latter was given in single or multiple doses, led to further, although insignificant, declines in repopulating ability, as well as PHSC and RU numbers. Interleukin-1 usage exacerbated the observed repopulating defect. There was evidence of replicative failure in individual cells, indicating a qualitative defect also. SUMMARY Additive stem cell depletion and qualitative replicative defect occur after chemotherapy-cytokine usage. However, the replicative defect of PHSC seen after addition of GM-CSF is not significantly worse than that seen with cytotoxic drug use alone.

Multiple granulocytic sarcomas in acute myeloblastic leukemia with simultaneous occurrence of t(8:21) and trisomy 8.

This report describes a rare case of multiple intracranial, extradural chloromas. A five year old African American male presented with headache, fever, and vomiting. The peripheral blood smear showed myeloblasts with Auer rods. The CTscan of the brain showed three intracranial, epidural lesions as well as son tissue masses in the retroorbital region and sphenoid sinuses. CTscan of the chest showed two paraspinal epidural thoracic masses. Pathology of the epidural intracranial mass revealed a granulocytic sarcoma. Cytogenetic analysis showed simultaneous occurrence oft (8;21) and trisomy 8. Following induction therapy, he is now in complete remission.

Effects of iron deficiency on the secretion of interleukin‐10 by mitogen‐activated and non‐activated murine spleen cells

Interleukin (IL)‐10 plays crucial regulatory roles in immune responses by inhibiting the secretion of several cytokines (IL‐2, IL‐12, interferon‐gamma (IFN‐γ)) and lymphocyte proliferation. Iron deficiency, a public health problem for children, alters these immune responses. To determine whether these changes are related to altered IL‐10 secretion, we measured IL‐10 in 24 and 48 h supernatant of spleen cell cultures from iron deficient (ID), control (C), pairfed (PF), and ID mice fed the control diet (iron repletion) for 3 (R3) and 14 (R14) days (d, n = 12/group). Mean levels of hemoglobin, hematocrit, and liver iron stores varied as follows: C ≈ PF ≈ R14 > R3 > ID (P < 0.01). Mean baseline IL‐10 levels of ID mice tended to be higher than those of other groups (P > 0.05, ANOVA). Mean IL‐10 levels secreted by concanavalin A (Con A) and antibody raised against cluster of differentiation molecule 3 (anti‐CD3)‐treated cells (±background) were lower in ID than in C (48 h) and iron replete mice (P < 0.05). Underfeeding also reduced IL‐10 secretion by anti‐CD3‐treated cells (48 h, P < 0.05). Lymphocyte proliferative responses to anti‐CD3 ± anti‐CD28 antibodies were lower in ID than in C and PF mice, and they were corrected by iron repletion (P < 0.05). IL‐10 levels negatively correlated with indicators of iron status (r ≤ −0.285) and lymphocyte proliferation (r ≤ −0.379 [r ≤ −0.743 for ID mice]), but positively correlated with IFN‐γ levels (r ≤ 0.47; P < 0.05). Data suggest that iron deficiency has a generalized deleterious effect on cells that secrete both cytokines. Reduced IL‐10 secretion by activated cells does not overcome the inhibition of lymphocyte proliferation due to other factors of T cell activation that are regulated by iron. J. Cell. Biochem. 90: 278–286, 2003.

Iron deficiency, but not underfeeding reduces the secretion of interferon-gamma by mitogen-activated murine spleen cells

Interferon-gamma (IFN-γ), a cytokine primarily secreted by T and natural killer cells regulates cell-mediated and innate immunity. Iron deficiency, a public health problem in children impairs immune function. To determine whether reduced IFN-γ contributes to impaired immunity, we measured IFN-γ in supernatants of activated (2.5 μg/ml concanavalin A, 50 ng/ml anti-CD3 antibody) spleen cells from control (C), iron-deficient (ID), pair-fed (PF), and iron-replete mice for 3 (R3) and 14 days (R14) (11-12/group). Except for iron content, the low iron (5 ppm) and control (50 ppm) diets had identical composition. Mean indices of iron status after 51 days of feeding were as follows: C=PF≈R14>R3>ID (p<0.01). Iron deficiency, but not pairfeeding reduced IFN-γ concentration in mitogen-treated cells by 30-43% (p<0.05); iron repletion improved it. Reduced IFN-γ was not simply due to differences in IL-12 (IFN-γ inducer), percentage of CD3+ T cells, or impaired cell proliferation because these indices were not always decreased. It was likely due to a defect in T cell activation that leads to IFN-γ gene expression. IFN-γ positively correlated with indicators of iron status, body, and thymus weights (r=0.238-0.472; p<0.05). Reduced IFN-γ secretion during iron deficiency may affect response to infections.

Antithrombin III (AT) and recombinant tissue plasminogen activator (R-TPA) used singly and in combination versus supportive care for treatment of endotoxin-induced disseminated intravascular coagulation (DIC) in the neonatal pig.

BackgroundDisseminated intravascular coagulation (DIC) is a pathological disturbance of the complex balance between coagulation and anticoagulation that is precipitated by vascular injury, acidosis, endotoxin release and/or sepsis and characterized by severe bleeding and excessive clotting. The innately low levels of coagulation factors found in newborn infants place them at extremely high risk for DIC. Anecdotal reports suggest that either anticoagulant or fibrinolytic therapy may alleviate some of the manifestations of DIC. To test the hypothesis that replacement of both anticoagulants and fibrinolytics may improve survival and outcome better than either single agent or supportive care alone, we utilized a neonatal piglet model of endotoxin-induced DIC.MethodsDIC was induced in twenty-seven neonatal pigs (7 to 14 days of age) by intravenous administration of E. coli endotoxin (800 μg/kg over 30 min). The piglets were divided into 4 groups on the basis of treatment protocol [A: supportive care alone; B: Antithrombin III (AT, 50 μg/kg bolus, 25 μg/kg per hr continuous infusion) and supportive care; C: Recombinant Tissue Plasminogen Activator (R-TPA, 25 μg/kg per hr continuous infusion) and supportive care; D: AT, R-TPA and supportive care] and monitored for 3 primary outcome parameters (survival time, macroscopic and microscopic organ involvement) and 4 secondary outcome parameters (hematocrit; platelet count; fibrinogen level; and antithrombin III level).ResultsCompared with supportive care alone, combination therapy with AT and R-TPA resulted in a significant improvement of survival time, hematocrit, AT level, macroscopic and microscopic organ involvement, p < 0.05. Compared with supportive care alone, R-TPA alone significantly reduced macroscopic organ involvement and AT alone increased AT levels.ConclusionThe findings suggest that combining AT, R-TPA and supportive care may prove more advantageous in treating the clinical manifestations of DIC in this neonatal pig model than either single modality or supportive care alone.

Gamma/delta T-cell lymphoma as a recurrent complication after transplantation.

We present a case of gamma-delta (γδ) T-cell lymphoma as a recurrent event in a pediatric liver transplant recipient. Liver transplantation was performed during infancy in an 18-month-old black girl because of cryptogenic cirrhosis. The patient received immunosuppression with cyclosporine and prednisone. Five years after transplantation, the patient was found to have a γδ T-cell lymphoma located in retroperitoneal nodes. She received chemotherapy and did well, remaining disease-free for 6 years. She remained only on prednisone for prevention of graft rejection, but was noted to have a non-tender skin nodule that upon biopsy proved to be again a γδ T-cell lymphoma. However, comparison of tissue from both tumors revealed that the second occurrence of this malignancy was a de novo event, differing from the first by immunophenotypic and immunohistochemical characteristics, and TCR rearrangement. The patient continues to do well, without evidence of disease recurrence, after being treated again with chemotherapy. A summary of the literature is presented and comparison of our case is made.