الفهرس 
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Abstract
Leukemia is a cancer that starts in early blood forming cells. Most often, leukemia is a cancer of white blood cells, but some leukemias start in other blood cell types. Leukemia is the most cancer in children and teens, accounting for almost 1 out of 3 cancers. ALL is most common in early childhood. chronic leukemias are rare in children. Most of these are CML. Acute leukemia can be classified based on morphologic characteristics, cytochemical features, immunologic characteristics and cytogenetic and molecular characteristics. A child with leukemia may develop fever. This is often caused by an infection, which may not improve even with antibiotic. It’s important to diagnose childhood leukemia as early as possible and to determine what type of leukemia it is so that treatment can be tailored to provide the best chance of success. Chemotherapy is the treatment with anti-cancer drugs that are given into a vein, a muscle, CSF or taken as pills. The treatment of leukemia uses combination of several chemo drugs. Doctors give chemotherapy in cycles, with each period of treatment followed by a rest period to give the body time to recover. Neutropenia is afrequent complication following chemotherapy in onchohematological practice. There is close connection between the severity of infection and the degree and the duration of neutropenia. The risk of infection increases significantly when the absolute neutrophil count is reduced. The duration of neutropenia bears a direct relationship with the risk
of infection.
Neutropenia is defined as decrease in absolute neutrophil count below
1500 cells/mm3. Neutropenia is classified as mild, moderate, severe or
profound neutropenia. FN is a clinical syndrome, refers to fever in patients
who have an absolute neutrophil count < 0.5 × 109 /L or < 1 ×109 /L that is
predicted to fall below 0.5 ×109 /L within 48 hours of onset of fever or sign
of sepsis.
The risk for developing complications in patients with febrile
neutropenia is variable. Differentiation between high and low risk patients
with fever and neutropenia has a significant impact of decisions that affect
the patient’s quality of life and overall medical costs.
Fungal infections are primary cause of morbidity and mortality in
patients with malignancies. In general patients those suffereing from
leukemia and lymphoma and are neutropenic following high dose of
chemotherapy or bone marrow transplantation are severely affected by
different fungal species. The most common funal pathogens are Candida
species (predominantly C albicans and C glabrata) and Aspergillus species.
Less common are Mucorales (Zygomycetes), Fusarium and Scedosporium
infections.
IFIs are classified into 4 categories according to EORTC/ MSG
definitions of IFD. This classification based on presence or absence of
clinical features and mycological evidence.
Several species of the yeast genus Candida are capable of causing
candidiasis. They are members of the normal flora of the skin, mucous membranes and gastrointestinal tract. Candidiasis is the most common
systemic mycosis. Candidemia has been defined as the presence of yeasts in
blood with or without visceral involvement. Hematogenous dissemination
may then occur to one or more other organ systems.
Invasive aspergillosis is defined as acute invasive disease which is a
life-threatening infection caused by the invasion of the tissue by Aspergilli.
The most frequently identified pathogens is Aspergillus fumigates. IA occurs
when the immune system fails to prevents Aspergillus spores from entering
the blood stream via the lungs, thus fungal cells are free to disseminate
throughout the body and can infect major organs such as lung, heart,
kidneys, bone, brain, liver and GIT.
Symptoms of invasive aspergillosis include fever, chills, shock,
delirium, seizures and blood clots. The person may develop kidney failure,
liver failure and breathing difficulty. IA is associated with high rate of
mortality among children with leukemia. Early diagnosis and initiation of
antifungal therapy are essential to reduce the high rate of mortality.
The diagnosis of IA can be established by the presence of Aspergillus
in sputum, blood and bronchoalveolar lavage by microscopy, culture or
antigen detection.
GM test aids in the diagnosis of IA and assessing response to therapy.
This test is an enzyme immunoassay that uses rat monoclonal antibodies,
which recognize (1,5) – linked galactofuranose. The assay is performed in
sequential steps and can be completed in about 4 hours. Results are
expressed as “ galactomannan index” this test demonstrates a good level of
sensitivity and specificity.
membranes and gastrointestinal tract. Candidiasis is the most common
systemic mycosis. Candidemia has been defined as the presence of yeasts in
blood with or without visceral involvement. Hematogenous dissemination
may then occur to one or more other organ systems.
Invasive aspergillosis is defined as acute invasive disease which is a
life-threatening infection caused by the invasion of the tissue by Aspergilli.
The most frequently identified pathogens is Aspergillus fumigates. IA occurs
when the immune system fails to prevents Aspergillus spores from entering
the blood stream via the lungs, thus fungal cells are free to disseminate
throughout the body and can infect major organs such as lung, heart,
kidneys, bone, brain, liver and GIT.
Symptoms of invasive aspergillosis include fever, chills, shock,
delirium, seizures and blood clots. The person may develop kidney failure,
liver failure and breathing difficulty. IA is associated with high rate of
mortality among children with leukemia. Early diagnosis and initiation of
antifungal therapy are essential to reduce the high rate of mortality.
The diagnosis of IA can be established by the presence of Aspergillus
in sputum, blood and bronchoalveolar lavage by microscopy, culture or
antigen detection.
GM test aids in the diagnosis of IA and assessing response to therapy.
This test is an enzyme immunoassay that uses rat monoclonal antibodies,
which recognize (1,5) – linked galactofuranose. The assay is performed in
sequential steps and can be completed in about 4 hours. Results are
expressed as “ galactomannan index” this test demonstrates a good level of
sensitivity and specificity.