Defects In Innate Immunity (Phagocytic Disorders) Flashcards
What is leukocyte adhesion deficiency (LAD)?
A defect that results in neutrophils not being able to aggregate or bind to intercellular adhesion molecules on endothelial cells which is necessary for their egress from the vasculature into tissues
Pts with LAD present with a history of what?
Recurrent infections of the oral and genital mucosa, skin, intestinal and respiratory tracts
What are the clinical manifestations of LAD?
Delayed detachment of the umbilical cord, slow wound healing, severe bacterial infections and failure to form pus
What is chronic granulomatous disease (CGD)?
A deficiency in NADPH oxidase in phagocytes leading to their failure to from superoxide and O2 radicals
Results in defective elimination of extracellular pathogens such as bacteria and fungi
Pts with CGD are susceptible to infections with what pathogen?
Catalase positive organisms (ex. Staphylococcus)
What is G6PD deficiency?
X linked recessive and most Pts are asymptomatic
Associated with anemia bc G6PD is important in RBC metabolism
Same manifestation as CGD
What is Chediak Higashi syndrome (CHS)?
Autosomal recessive molecular defects in the structure of neutrophil granules leading to abnormalities in chemotaxis and degranulation
Pts prone to recurrent pyogenic granulomas caused by bacterial infections
What is commonly seen in CHS pts at age 30?
Wheel chair bound and death by infection
What is the appearance of neutrophil granules in pts with CHS?
Abnormal giant granules that dont contain cathepsin G or etalase
Describe how CHS is biphasic
1 phase: susceptibility to infections
2nd phase: accelerated lymphoproliferative syndrome with hepatosplenomegaly and lymphadenopathy
How is a diagnosis of CHS made?
Observation of azurophilic giant cytoplasm inclusions in RBCs, partial albinism and no NK activity
Which gender is CGD more common in?
Males
Both CGD and G6PD are characterized by a tendency to form what?
Granulomas
