Immunology Flashcards
Name the responses to infection
- resolution; normal immune response, pathogen cleared, tissue repaired
- latent infection; normal immune response, pathogen controlled (no replication), infection can re-occur
- chronic infection; defective immune response, pathogen not cleared or controlled
What does SPUR stand for?
S = serious infections, unresponsive to oral antibiotics P = persistent infections; early structural damage, chronic infections U = unusual infections; unusual organisms, unusual sites R = recurrent infections; one or two major and recurrent minor infections in one year
Name some other features that may be suggestive of primary immune deficiency
- weight loss or failure to thrive
- severe skin rash (eczema)
- chronic diarrhoea
- mouth ulceration
- unusual autoimmune disease
- lymphoproliferative disorders
- cancer
- family history
Name some conditions associated with secondary immune deficiency
- physiological immune deficiency
- infection
- treatment interventions
- malignancy
- biochemical and nutritional disorders
Describe primary immunodeficiency disorders
- respiratory disease are the main and initial manifestation in most cases and the most common complication
- pulmonary complications cause significant morbidity and mortality in patients with PIDs
- early diagnosis and appropriate treatment can prevent or at least slow the development of respiratory complications
What is congenital neutropenia?
Abnormally low concentration of neutrophils in the blood
Describe the treatment of phagocyte deficiencies
- immunoglobulin replacement therapy
- aggressive management of infection
- definitive therapy; gene therapy, stem cell transplant. recombinant G-CSF
- complications; life threatening infections, graft vs host disease after stem cell transplant
Describe the clinical phenotype of SCID
- unwell by three months of age
- persistent diarrhoea
- failure to thrive
- infections of all types
- unusual skin disease
- Fhx of early infant death
- wont respond to vaccines, cannot receive live vaccines
Define autoimmunity
Defined as the presence of immune responses against self-tissue / cells
What are the specific tolerance mechanism required in the presence of autoreactive T cells and B cells?
- deletion of self-reactive lymphocytes in primary lymphoid tissues (central tolerance)
- inactivation of self-reactive lymphocytes in peripheral tissues that escape central tolerance (peripheral tolerance) eg. regulatory t cells
Describe self-tolerance
Non-responsiveness of lymphocytes to specific self-antigens, arises at two stages of lymphocyte development and function
What is the function of regulatory T cells?
They are crucial for the suppressing of hyper-reactive or auto-reactive T cells via production of anti-inflammatory cytokines
What does autoimmunity result from?
Failure of immunological tolerance, the process by which the immune system recognised and accepts self-tissue
Develops when self-reactive lymphocytes escape from these tolerance mechanisms and become activated
What are monogenic disorders
Single gene defects causing autoimmune diseases are rare
What is IPEX syndrome?
A rare genetic disorder of immune dysregulation which presents early in childhood and is characterised by overwhelming systemic autoimmunity
