W7 - 2ndary immunodeficiency & HIV Flashcards
Which is more common - 2ndary or primary immune deficiencies?
2ndary
Give examples (7) of 2ndary immune deficiencies. What is the commonest cause?
- infectious diseases: HIV
- environmental stress
- Age extremes: prematurity & old age
- Surgery and trauma, eg) splenectomy
- Immunosuppressive drugs
- Genetic + metabolic diseases
- Malnutrition (COMMONEST worldwide)
Name 4 clinical features of immune deficiencies
- Infections - severe, persistent, recurrent, unusual
- Autoimmune conditions (cytopaenias) & allergic disease
- Persistent inflammation
- Cancer (especially those virally associated EBV, HHV-8)
Name 4 classes of drugs that cause immune deficiencies. Give examples of each
- Small molecules
- Glucocorticoids & mineralocorticoids
- cytotoxic agents => methotrexate, mycophenolate, cyclophosphamide, azathioprine
- Calcineurin inhibitors => cyclosporine, tacrolimus
- anti-epileptic drugs => phenytoin, carbamazepine, levetiracetam
- DMARDs => sulphasalazine, leflunomide - JAK inhibitors => tofacitinib, ruxolitinib
- Biologic agents => anti-CD20 (rituximab)/anti-CD38, anti-TNFa (infliximab, etanercept)
- Cellular therapy => anti-CD19/BCMA Car-T cell therapy
Anti-TNF agents are linked to reactivation of ______________
TB
* hence why patients are screened for TB prior to starting anti-TNF
Name 2 anti-TNF alpha drugs
infliximab, etanercept
Name an anti-CD20 drug
Rituximab
B and plasma cell cancers can present with immune deficiency, out of which the most common immune deficiency is
antibody deficiency syndromes
Name 4 B cell lymphoproliferative disorders associated with immune deficiency
- Multiple myeloma (MM)
- Chronic lymphocytic leukaemia (CLL)
- Non Hodgkin’s lymphoma (NHL)
- Monoclonal gammopathy of uncertain significance
What is Good’s syndrome?
thymoma AND antibody deficiency
What is the B cell and T cell profile of someone with Good’s syndrome?
What sort of infections are they susceptible to?
What sort of autoimmune diseases are they susceptible to? Why do they form autoimmune diseases?
B cell absent, T cell absent in 50%
CMV PJ pneumonia, mucosal and cutaneous candida infections
Pure red cell aplasia, myasthenia gravis, Lichen planus => b/c they lack thymus for central selection of these T cells
Frontline investigations for immune deficiency
FISH for it:
F - FBC => Hb, neutrophil, lymphocyte, platelet count
I - Immunoglobulins => IgG, IgA, IgM, IgE
S - serum complement (C3, C4)
H - HIV test (18-80 yrs)
other chemistry tests:
- renal + liver profile
- calcium + bone profile
- total protein + albumin
- urine protein/Cr ratio
- serum protein electrophoresis (SPE)
- serum free light chains
Describe the use of serum protein electrophoresis (SPE) test
SPE separation of serum proteins by charge
Detection of discrete bands
monoclonal protein associated with => MM, WMG, NHL, MGUS
Con of SPE test
can miss free light chain disease - seen in 20% of MM
Second line investigations for immune deficiencies
- Check for vaccine antibody concentration => can also perform dynamic test where you vaccinate then proceed to check ab response
- Flow cytometry => analysis of lymphocyte subsets
Describe management (5) of secondary immune deficiency
- Treat underlying cause
- Advise on measures to reduce exposure to infection
- Immunisation against respiratory viruses/bacteria + vaccines to household contacts
- Education to treat bacterial infections promptly
- Prophylactic antibiotics for recurrent (>3/yr) bacterial infections