Disorders of Neutrophils, Monocytes, and Macrophages

Flashcards covering various disorders affecting neutrophils, monocytes, and macrophages, including their causes, mechanisms, symptoms, and cellular characteristics.

What is 'Lazy Leukocyte Syndrome'?

A condition where neutrophils are unable to reach the site of infection due to defective motility and chemotaxis.

What are the key characteristics of Chediak-Higashi Syndrome?

A rare autosomal disease characterized by altered lysosomes/granules, delayed bacterial killing, frequent skin infections, photosensitivity, hypopigmentation, and is generally fatal by age 7.

What is the primary defect in Chronic Granulomatous Disease (CGD)?

Phagocytes cannot generate NADPH oxidase, leading to an inability to produce hydrogen peroxide (H2O2) and perform the 'oxidative burst.'

What types of infections are commonly seen in patients with Chronic Granulomatous Disease (CGD)?

Recurrent infections with catalase-positive bacteria and fungal infections, often accompanied by granulomas.

What is the main problem in Complement C3 Receptor Deficiency?

An adhesion deficiency where neutrophils cannot adhere to each other or epithelial cells, impairing phagocytosis of opsonized organisms.

What are common clinical manifestations of Complement C3 Receptor Deficiency?

Early onset of bacterial infections (skin, mucosal, ear, gingivitis), neutropenia, and a depressed inflammatory response.

What is Myeloperoxidase Deficiency, and how common is it?

It is the most common phagocyte disorder, primarily an autosomal recessive inherited condition where myeloperoxidase is decreased or absent.

What is the primary effect of Myeloperoxidase Deficiency on pathogen killing?

It causes a mild to moderate defect in bacterial killing and a marked defect in fungal killing, though most patients are asymptomatic.

What is the underlying cause of Specific Granule Deficiency?

Neutrophils are unable to synthesize specific granules or their contents during differentiation in the bone marrow.

What are common clinical features of Specific Granule Deficiency?

Severe, chronic cutaneous infections (ulcers, abscesses) and chronic/recurrent lung infections (pneumonia, abscesses) due to a decreased inflammatory response.

What enzyme is deficient in Gaucher Disease, and what accumulates as a result?

Alpha-glucocerebrosidase deficiency, leading to the accumulation of cerebroside in histiocytes.

Describe the characteristic appearance of a Gaucher cell.

Large cells with 1-3 eccentric nuclei and 'wrinkled' cytoplasm, typically found in bone marrow, spleen, and other phagocyte-rich organs.

What are the main types of Gaucher Disease, and how do they differ in terms of neurological involvement?

Type 1 is non-neuropathic (brain not involved), while Types 2 and 3 are neuropathic (brain involved).

What is the enzymatic defect in Niemann-Pick Disease Types A and B?

Sphingomyelinase deficiency, leading to sphingomyelin accumulation in mononuclear phagocytes.

What is the metabolic defect in Niemann-Pick Disease Type C?

Inability to metabolize cholesterol, causing cholesterol to accumulate in the liver and spleen.

How does a 'Pick cell' differ in appearance from a 'Gaucher cell'?

A Pick cell has 'foamy' cytoplasm, whereas a Gaucher cell has 'wrinkled' cytoplasm.