Nosocomial infections and fever of unknown origin in pediatric hematology/oncology unit: a retrospective annual study.

BACKGROUND: pediatric hematology/oncology patients are faced with an increased risk of nosocomial infections (NIs) that vary in different populations and different institutions with considerable morbidity and mortality. This study was undertaken to assess the frequency and patterns of NIs in 1564 pediatric patients and to determine the prevalence of causative organisms and their antimicrobial sensitivity. METHODS: a retrospective analysis was made in the patients admitted between January 2007 and January 2008 to the pediatric hematoloy/oncology unit of Mansoura University, Egypt. The 1564 patients showed 2084 admissions and 27 092 inpatient days. The Centers for Disease Control and Prevention criteria were used as a standard definition for NI. RESULTS: the overall rate of NIs in all patients and neutropenic patients was 8.6 and 25.3 per 1000 patient-days respectively. The frequent sites of NIs were blood stream (42.7%), the respiratory system (25.3%), the urinary system (22.2%) and the central nervous system (9.8%), whereas nosocomial fever of unknown origin constituted 52.9% of cases. The incidence of NIs was significantly higher during neutropenic days (P<0.001). Gram-positive organisms represented 64.5% of pathogens (Staphylococci 71.5%, Streptococci 16%, and pneumococci 7%), and Gram-negative organisms represented 30% (E. coli 48.6%, Klebsiella 15.7%, Pseudomonas 35.7%, and C. albicans 5.5%). Positive cultures were more frequent in summer (July to September). Susceptibility of isolated organisms was relatively low (cefoperazone/sulbactam 49.9%, amikacin 35.9%, imipenem/cilastin 34.4%, cefoperazone 33.6%, and vancomycin 36.5%). Methicillin-resistant S. aureus, extended spectrum beta lactamase and vancomycin resistant enterococci represented 30%, 45% and 75% of isolated S. aureus, Gram-negative organisms and Enterococci, respectively. CONCLUSIONS: blood stream infection and fever of unknown origin are the most common nosocomial infections in pediatric hematology/oncology patients with a higher risk during neutropenic days. Isolated organisms are multi-drug resistant, predominantly Gram-positive pathogens with a high incidence of methicillin-resistant S. aureus, extended spectrum beta lactamase and vancomycin resistant enterococci organisms.

Bone mineral density in newly diagnosed children with neuroblastoma.

BACKGROUND: Neuroblastoma is the second most common extracranial malignant tumor of childhood and the most common solid tumor of infancy which is characterized by bone metastasis. Previous reports on bone mineral density (BMD) in patients with leukemia and solid malignancies concentrate on long-term survivors and on the effect of chemotherapeutic agents and irradiation. Also, evaluation of BMD in neuroblastoma was reported in few studies which were conducted upon adult survivors of childhood cancer. Previous studies on both acute leukemia and lymphoma patients suggested that the disease process itself played a role in decrease BMD. METHODS: We evaluated 27 patients with newly diagnosed neuroblastoma for both lumbar (L2-L4) BMD and total BMD using dual energy X-ray absorptiometery (DXA) scan to highlight the effect of neuroblastoma as a disease process on BMD as this disease characterized by bone metastasis. RESULTS: Three out of the 27 patients showed low bone mass in both lumbar and total BMD studies. CONCLUSION: Low bone mass may occur in early disease process of neuroblastoma and it is important to consider BMD assessment during the early course of the disease as well as the long-term survivors as a part of the patient screening in suspected cases.

Prognostic value of the t(14;18)(q32;q21) in patients with diffuse large B-cell lymphoma.

The prognostic significance of the t(14;18) in diffuse large B-cell lymphoma is still controversial. To assess the impact of the t(14;18) on patient survival, we investigated 26 patients with diffuse large B-cell lymphoma for the presence of t(14;18). The t(14;18) was detected in 90.9% of patients with high international prognostic index score. The five-year overall survival was 0.0% and 68.75% in positive and negative cases of t(14;18) respectively. The detection of the t(14;18) combined with the international prognostic index score is a useful strategy for more appropriate risk stratification and prediction of outcome of patients with diffuse large B-cell lymphoma.

Histiocytosis disorders in Northeast Egypt: epidemiology and survival studies (a 5-year study).

Histiocytosis disorders include a wide group of disorders characterized by monocytes, macrophages and dendritic cell infiltration of different tissues. There are few clinico-epidemiologic studies of such disease. Our study was designed to look at the clinico-epidemiological features and outcome of patients with histiocytosis disorders in Northeast Egypt. Twenty-seven cases with histiocytosis disorders accrued over a 5-year period were analyzed and classified as having unifocal, multifocal, or multisystem disease. They were 14 males and 13 females. Twenty-two patients representing 81.5% of cases were more than two years of age while 5 patients (18.5%) were less than 2 years. Lymphadenopathy was the commonest presentation (55.55%) followed by bone lesions (44.44%). Involvement was unifocal in 12, multifocal in 10, and multisystem in 5 cases. The histological features were relatively uniform regardless of the clinical severity, and consisted of Langerhans cells, eosinophils, histiocytes, plasma cells, giant cells and fibrosis. The treatment consisted of a combination of surgery, chemotherapy, and/or radiotherapy. Lymphadenopathy was the most common clinical presentation in our locality. Response to treatment was poor in patients with multisystem disease. Patients with age less than 2 years were more likely to have increased risk of morbidity and mortality, due to widespread disease.

Immune reconstitution during maintenance therapy in children with acute lymphoblastic leukemia, relation to co-existing infection.

Immunosuppression is a major side effect of cancer chemotherapy. The process of immune reconstitution can be dissimilar according to the nature of the disease, type and doses of drugs, and age of the patients. Recently, several studies have examined immune reconstitution in children and young adults after intensive chemotherapy for solid tumours or stem cell transplantation. The aim of the present study is to evaluate immune reconstitution (cellular and humoral) in children with acute lymphoblastic leukemia during the maintenance phase of therapy and to correlate between the complicating infections and the abnormalities in immune system during reconstitution. To achieve this goal, 36 children with acute lymphoblastic leukemia (24 females and 12 males) in the maintenance phase of therapy with 12 healthy children of matched age and sex served as a control group were recruited in this study. The patients were taken consecutively from the Hematology/Oncology Outpatient Clinic of Mansoura University Children's Hospital (MUCH). They were subjected to thorough history taking, clinical examination and laboratory investigations in the form of: complete blood count, serum creatinine, liver function tests and evaluation of the immune system by estimation of CD3, CD4, CD8, CD19 and CD56 (cellular immunity) by flow cytometry and immunoglobulins A, M and G (humoral immunity) at the first and the third month of maintenance therapy. The results of the study documented presence and persistence of leucopenia and lymphopenia during maintenance therapy with decreased medians of CD3, CD4 and CD8 from the first to the third month of therapy and in comparison to the control group. The other markers CD19, CD56, IgA, IgM, IgG and CD4/CD8 ratio showed increasing median from the first to the third month of therapy. Also we detect a significant correlation between infection and CD19 and serum IgM at the first month and between infection and CD19, IgM and CD4/CD8 ratio at the third month of therapy. In conclusion, persistent immunosuppression is documented in children with acute lymphoblastic leukemia during maintenance therapy. Reconstitution of B lymphocytes and Natural killer cells occurs early while T cell reconstitution shows delayed recovery of both T helper and T suppressor cells. Immunosupression during maintenance therapy has no major clinical impact in terms of increased incidence or severity of systemic infections.

Low bone mass in children with malignant lymphoma.

The aim of this work was to study the effect of disease process on bone mass and calcium homeo-stasis in children with malignant lymphoma at diagnosis, 3 months after starting chemotherapy, and after 1 year. Evaluation of lumber vertebrae (L2-L4) bone mineral density using dual-energy X-ray absorptiometry and calcium homeostasis parameters and bone turnover biochemical markers (serum osteocalcin and urinary deoxypyridinoline) had been assayed in twenty lymphoma patients at presentation and after treatment. Low bone mass for chronological age was observed in 4 patients (20%) at diagnosis and persisted after 3 months and 1 year. Parathyroid hormone level demonstrated no differences between children with lymphoma at different stages of therapy and controls, while 25(OH) D(3) was significantly lower in lymphoma patients at different stages of therapy as compared to controls (p < .001). Osteocalcin was significantly lower in lymphoma patients at different stages of therapy. Deoxypyridinoline showed only significant higher values after 3 months of therapy compared to controls (p = .01). In conclusion, low bone mass was observed in children with lymphoma and is related to decreased osteoblastic activity and decreased mineralization of bone.

Unbalanced bone turnover in children with beta-thalassemia.

The life expectancy of patients with thalassemia has greatly improved over the last decade as a result of regular transfusions and increased compliance with iron chelation therapy, however, this improvement is often accompanied by a series of serious complications including osteopenia and osteoporosis. The pathogenesis of these skeletal disorders is multifactorial which may be due to hormonal deficiency, compromised nutritional status, bone marrow expansion due to erythroid hyperplasia, increased iron stores or desferrioxamine toxicity. The non invasive assessment of bone turnover has markedly improved with the development of specific and sensitive markers of bone formation. The aim of this work is to assess the value of bone formation markers in patients with beta-thalassemia. To achieve this goal, 36 patients with thalassemia were recruited in this study. There were 20 males (56.6%) and 16 females (44.4%) and their ages ranged from 3 to 18 years. A control group of 20 apparently healthy subjects of matched age and sex was used. The patients were selected from the outpatient clinic and inpatients of the Hematology/Oncology Unit of Mansoura University Children's Hospital (MUCH). The selected subjects were subjected to thorough history taking, clinical examination, radiological evaluation and laboratory investigations in the form of: complete blood count, serum iron, serum ferritin, total iron binding capacity, serum calcium, serum phosphorus and estimation of bone formation markers as alkaline phosphatase and osteocalcin. The results were as follows: serum calcium level was within normal range and showed no statistical significance (p = 0.176) when compared to the control group, while serum phosphorus level was significantly higher in thalassemic patients than the controls (p = 0.002); this may reflect hypoparathyroidism. Analysis of the level of bone formation markers showed serum alkaline phosphatase levels slightly higher in patients than controls but not significant (p = 0.055), and this elevation can be referred to associated liver disease in these patients. On the other hand, osteocalcin level was significantly lower in patients than controls (p = 0.011), and this may be due to osteoblast poisoning by iron overload. In conclusion, thalassemic patients have unbalanced bone turnover between the bone formation and resorption markers and this is evidenced by non significant changes or decreased levels of bone formation markers, while bone resorption is an active process.

Low turnover bone disease in Egyptian children with acute leukemia.

The aim of this work was to study bone turnover markers, calcium homeostasis and bone mineral density (BMD) in children with acute leukemia at diagnosis, after induction chemotherapy, and during maintenance therapy to delineate abnormalities present. After evaluation of L2-L4 BMD using dual-energy X-ray absorptiometry in patients with acute myeloid and lymphoid leukemia at presentation and after treatment, the results were compared to 352 healthy age- and sex-matched Egyptian controls. Calcium homeostasis parameters and bone turnover biochemical markers (serum osteocalcin and urinary deoxypyridinoline) were also assayed and the results were compared to 12 healthy age- and sex-matched controls. Osteopenia was observed at diagnosis and during treatment in patients with acute leukemia. At diagnosis osteopenia was observed in 27 patients (62.8%): 10 (23.3%) had non severe osteopenia and 17 (39.5%) had severe osteopenia. This low BMD persisted in those who were followed up. Parathyroid hormone (PTH) (pg/ml) levels demonstrated non significant differences between children with acute leukemia at different stages of therapy and controls, while, 25 (OH) D3 (ng/ml) was significantly lower in acute leukemia patients at different stages of therapy compared to controls (p<0.001). Osteocalcin (ng/ml) is significantly lower in patients at different stages of the disease compared to controls (p<0.001) but there was no significant difference between patients at different stages of therapy. Deoxy-pyridoline cross links showed non-significant difference between the different types of acute leukemia and with controls. Osteopenia is a significant problem in children with acute leukemia at presentation and after chemotherapy. Osteopenia in acute leukemia appears to be of the low turnover type (decreased osteoblastic activity and decreased bone mineralization).

Pretreatment cystatin C in children with malignancy: can it predict chemotherapy-induced glomerular filtration rate reduction during the induction phase?

BACKGROUND: Monitoring of kidney function is essential during chemotherapy. Serum creatinine is of limited value in early detection of renal insufficiency. The cystatin C level has been proved to be a good marker for detection of mild reduction in glomerular filtration rate. PURPOSE: To evaluate the validity of the pretreatment serum cystatin C level in predicting significant reduction of the glomerular filtration rate during the induction phase of chemotherapy. PATIENTS AND METHODS: Serum levels of cystatin C and creatinine and corrected creatinine clearance were assessed in 34 children with different types of malignancy just before the start of chemotherapy and again in 33 of them 1 month later. Patients were compared with 14 healthy controls of matched age and sex. RESULTS: Before chemotherapy, all patients when compared with controls had normal levels of cystatin C (P = 0.1) and creatinine (P = 0.62) and normal corrected creatinine clearance (P = 0.76). One month after chemotherapy, patients showed a significant increase in their cystatin C levels (P < 0.001) and a significant decrease in their corrected creatinine clearance (P < 0.001). However, creatinine levels did not change significantly (P = 0.65). Corrected creatinine clearance negatively correlated significantly with both cystatin C and creatinine levels (r = -0.622, P < 0.001; r = -0.346, P = 0.045, respectively) before chemotherapy and also 1 month after chemotherapy (r = -0.577, P < 0.001; r = -0.45, P = 0.009, respectively). When pretreatment levels of cystatin C and creatinine were used to predict patients who developed a reduction in corrected creatinine clearance of more than 20% after therapy, only the cystatin C level was statistically significant (P = 0.03). A cutoff point of 0.57 mg/L with sensitivity of 77.8%, specificity of 63%, and overall accuracy of 74% was suggested. CONCLUSIONS: Children with malignant diseases develop significant reduction in their glomerular filtration rate during the induction phase of chemotherapy, although their serum creatinine level may not change significantly. Cystatin C, as a more sensitive marker than creatinine for the assessment of glomerular filtration rate, can be used to predict patients who would have a higher risk of renal impairment during the induction phase of chemotherapy and who thus would require more frequent renal function assessment to consider adjustment of the chemotherapy dose if indicated.