Immune-Deficiency Diseases Flashcards Preview

Year 3: CSP & PH > Immune-Deficiency Diseases > Flashcards

Flashcards in Immune-Deficiency Diseases Deck (15)
Loading flashcards...

Describe X-linked gammaglobulinaemia

• No antibodies (no B lymphocytes)
• Aetiology: very rare, affects boys
• Presentation: usually in 2nd 6 months of life with chest infections, sinusitis, otitis media and other bacterial infections
• Prognosis: if not treated will get worse and worse and will die in childhood/early adulthood
• Treatment: antibody replacement and antibiotics where needed, usually replacement IgG


Describe severe combined immune deficiency (SCID)

• Primary causes:
o Reticular dysgenesis - only red cells and platelets in the blood, These individuals only live a few days before dying of overwhelming infection


Describe common variable immune deficiency

• Aetiology: any gender, presents at any age
• Pathology: antibodies are low (two classes of antibodies must be low to fit diagnosis


Outline the causes of antibody deficiency

Primary = x-linked gammaglobulinaemia, SCID, CVID
Secondary = infections (AIDs), malignant disease, trauma (burns, penetrating injury), loss of antibodies (nephrotic syndrome), drug-induced


Why may rituximab cause an antibody deficiency?

Anti-CD20 on B cells - depletion of B cells --> specific antibody deficiency may occur


What are the causes of T-lymphocyte deficiency?

Primary = DiGeorge syndrome, Nucleoside phosphorylase and adenine deaminase deficiency
Secondary = AIDs, immunosuppressive drugs, cytotoxic drugs (methotrexate)


Describe DiGeorge syndrome

> Genetics: deletion of part of chromosome 22
> Pathophysiology: defect in chromosome 22 defect in 3rd and 4th pharyngeal arches no thymus or parathyroid, facial abnormalities, great vessel abnormalities complete T cell absence


What are the causes of neutropenia?

Primary = cyclical neutropenia, Kostmann syndrome, chronic benign neutropenia
Secondary = malignancy (leukaemia, lymphoma), drugs (cytotoxic therapy), infections


What infections are associated with neutropenia?

Frequently starts as oral soreness, gingivitis and then severe pharyngitis with upper and lower respiratory tract infections.
o Bacteria – Pseudomonas, E. Coli, enterobacteria (gram –ve rods), enterococci, staphylococci
o Fungi – candida, aspergillus


What are the causes of neutrophil function defects?

Chronic granulomatous disease, leukocyte adhesion deficiency (LAD), diabetes mellitus


Describe chronic granulomatous disease

♣ Genetics: X-linked only in boys
♣ Pathophysiology: inability to initiate respiratory burst in phagocytes can’t generate superoxide
♣ Presentation: before the age of 5 with pneumonia, osteomyelitis, infective arthritis, skin infections
♣ Tests: nitroblue tetrazolium test, (normal phagocytes can decolourise these dyes whereas a patient with this disease’s phagocytes cannot)
♣ Treatment: antibiotics, interferon, bone marrow transplant


Describe leukocyte adhesion deficiency (LAD)

♣ Genetics: very rare, autosomal recessive disease. Deficiency of CD18 (a part of neutrophil adhesion molecule)
♣ Pathophysiology: as a result of mutation, neutrophils cannot pass through post-capillary venule walls during inflammation
♣ Presentation: failure of umbilical cord to slough, pneumonia, gingivitis, peritonitis
♣ Treatment: antibiotics, bone marrow or stem cell transplant


Describe Wiskott-Aldrich syndrome

o Genetics: X-linked
o Pathophysiology: defective cytoskeletal protein found in haemopoetic cells . Thrombocytopenia causes bleeding and affects the B and T cells
o Presentation: infections (ears and sinuses) and lymphomas


Describe Chediak-Higashi syndrome

o Pathophysiology: defect in moving material into lysosomes mostly affects phagocytes but also affects the production of the cytolytic granules used by CD8+ T cells and natural killer cells
o Presentation: neutropenia, giant inclusion bodies in leukocytes, partial albinism, peripheral neurpathy
o Associated infections: bacterial infections


Describe how classical complement deficiency presents

Lupus-like picture due to poor handling of immune complexes. Low C3