Maria Velez

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.

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.

Focal Segmental Glomerulosclerosis in Children With Acute Lymphocytic Leukemia: Case Reports and Review of Literature

Purpose: To report the occurrence of focal segmental glomerulosclerosis (FSGS) in children with acute lymphocytic leukemia (ALL), discuss pathogenesis and problems in management. Patients and Methods: Progressive renal dysfunction developed in two adolescent black girls with high-risk ALL who underwent renal biopsies that were consistent with FSGS. In both patients, no known etiologic factors, such as systemic lupus erythematosus. poststreptococcal glomerulonephritis. sickle cell anemia, or acquired immunodeficiency syndrome, were evident. FSGS induced by Adriamycin (Pharmacia & Upjohn. Columbus. OH) has been observed experimentally in rats. The patients had received anthracyclines and methotrexate. a known nephrotoxic chemotherapeutic agent. Results: One patient progressed to chronic renal failure and required prolonged dialysis followed by renal transplantation, though the leukemia remained in remission. The other patient is also in remission and on maintenance treatment for leukemia. She has persistent proteinuria and is currently undergoing a trial of high-dose steroid therapy. Conclusion: The combination of FSGS with leukemia poses a management challenge to the clinician in terms of further treatment with potentially nephrotoxic drugs, complications of nephrotic syndrome (including infections), and timing of renal transplantation. Future studies should address whether FSGS represents a glomerular response to anthracycline-induced injury in susceptible black persons.

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.

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.

Differences in iron requirements by concanavalin A-treated and anti- CD3-treated murine splenic lymphocytes

Fe availability is critical for optimal lymphocyte proliferation; however, the minimum required levels are unknown. Such information is valuable when assessing in vitro immune responses in Fe-deficient subjects, because serum (Fe) added to the culture medium may replete lymphocytes. To address this issue, splenic lymphocytes obtained from seventeen 3-month-old C57BL/6 mice were incubated without and with 1 mg/l concanavalin A or 50 microg/l anti-CD3 antibody in media that contained between 0.113 and 9.74 micromol Fe/l. Fe was provided by either fetal calf serum (FCS, 0-100 ml/l), newborn calf serum (NBCS, 0-100 ml/l), or NBCS (10 ml/l) plus ferric ammonium citrate. As expected, the rate of DNA synthesis increased with Fe levels (P<0.01). Maximum DNA synthesis was obtained with 2.26 micromol Fe/l (50 ml FCS/l) for concanavalin A and 0.895 micromol/l (20 ml FCS/l) for anti-CD3-treated cells. In serum-free media (0.113 micromol Fe/l), the proliferative responses to concanavalin A were below the background, while they rose 5.5-fold in anti-CD3-treated cells (P<0.05). In apotransferrin-supplemented media (0.13 micromol Fe/l), the proliferative responses to concanavalin A and anti-CD3 antibody were 18.6 and 71 %, respectively, of that obtained with 4.66 micromol Fe/l (100 ml FCS/l). Interleukin 2 secretion also followed the same trend as lymphocyte proliferation. Since differences between both mitogens persisted after FCS was substituted with NBCS, we can rule out an effect on ribonucleotide reductase activity, or by other serum growth factors. We speculate an Fe effect at an early step of T-cell activation. Data suggest that the minimum Fe concentration required for lymphocyte proliferation varies with the mitogen.

Acute Perforative Appendicitis During Preoperative Chemotherapy for Wilms Tumor

Infectious complications are not uncommon in children undergoing treatment for cancer. Abdominal pain, especially right lower quadrant pain secondary to appendiceal and cecal inflammation, is a major concern in immunocompromised hosts and a potential source of sepsis. The authors report the case of a child who developed acute perforative appendicitis requiring appendectomy while on preoperative chemotherapy for Wilms tumor, stage IV, favorable histology. Problems related to diagnosis and management of acute abdominal pain and infection in an immunocompromised child with an abdominal mass are discussed along with a review of the literature.

Characterization of S-glutathionyl hemoglobin in homozygous sickle cell disease.

S-glutathionyl hemoglobin is a proposed biomarker of oxidative stress but has not been measured in sickle cell disease patients. Unlike the S-glutathionyl adduct of normal adult hemoglobin, S-glutathionyl sickle hemoglobin (HbSSG) cannot be directly measured by capillary isoelectric focusing, because it coelutes with fetal hemoglobin (HbF). This suggests that HbF, measured in sickle cell patients with or without hydroxyurea therapy, might contain endogenous HbSSG. As S-glutathionyl hemoglobin can form during sample storage, HbSSG could falsely elevate HbF levels in stored samples. We measured HbSSG based on the quantitative difference in the heterogeneous HbF/HbSSG peak before and after hemolysates were treated with dithiothreitol. Paired t tests showed that dithiothreitol reduced HbF/HbSSG in blood from pediatric sickle cell patients (n=25, mean decrease±SD=1.0%±0.6, P<0.05) but not in normal infants (n=25). Higher HbF levels in hydroxyurea-treated patients (n=5) were not attributable to HbSSG. HbSSG increased significantly within 1 day in samples stored at −20°C but was unchanged in samples stored 60 days at−70°C. We conclude that blood from sickle cell patients contained up to 2.2% HbSSG, and that endogenous HbSSG is a minor interferent in the measurement of HbF in fresh blood but a major interferent in improperly stored samples.

Pediatric Pulmonary Embolism Diagnostic and Management Challenges

A rare case of massive pulmonary embolism is presented in an oligosymptomatic teenager with predisposing factors. Computed tomography pulmonary angiography supported by three-dimensional reconstruction was diagnostic. The embolus qualified as massive by conventional anatomical guidelines, but as low risk by more recent functional criteria. Functional assessment has complemented morphologic assessment for risk stratification in adult patients. Such evidence is scarce in pediatrics. The patient underwent surgical embolectomy, followed by prophylactic anticoagulation, without further events. Diagnostic and management challenges are discussed.