Immunology Flashcards
What is measured in serum to diagnose allergic sensitivity
IgE
Which immunologic markers indicate a “true” peanut allergy and high risk of severe reactions
Ara h1, ara h 2, ara h 3 specific IgE
Name 10 red flags for primary immunodeficiency
•≥8 new ear infections within 1 year
• ≥2 serious sinus infections within 1 year
• ≥2 months on antibiotics with little effect
• ≥2 pneumonias within 1 year
•≥2 deep seated infections
• failure to thrive infant
• recurrent, deep skin/organ abscesses
• persistent thrush in mouth/elsewhere on skin after age 1
• need iv antibiotics to clear infections
• family history
Name the 3 most common primary immunodeficiency syndromes
•Antibody (50%)
• combined (20%)
• phagocytic (18%)
Which screening procedures should be done for primary immunodeficiency syndromes (4)
• FBC and differential
• total serum immunoglobulins nb ( G, A, M, E. IgG subclasses if necessary)
• total haemolytic complement: c3 and c4
• flowcytometry of T cells/subsets (Cd3,4,8), circulating B cells (cd19), nk cells (cd56)
Which follow up procedures should be ordered for primary immunodeficiencies if the screening is positive (4)
•Neutrophil functions (antimicrrobial activity, adhesion molecule expression)
• monocyte/macrophage functions (cytokine production eg IL2, IFN gamma receptor)
• t lymphocyte functions (proliferation, cytokines)
• molecular/genetic analysis private
Which immunoglobulins are detectable in acute infections
• IgM (within days, peak day 7-10)
• igG (7 -14 days after onset, stay in circulation for months)
Increased titres must be shown in follow up samples to confirm active infection in 4-6 weeks
Which immunoglobulins are detectable in chronic infections
IgG
4 fold increase in titer
(Chlamydia: IgG, A ,M )
Name 3 nuclear antigens that are diagnostic for SLE
• ds dna (>85%)
• SMDP (30%)
• ribosomal P for neuropsychiatric SLE
( Help diagnosis: SSA ( ro 52/ro60 ) 30-40%, SSB (La) 10-30%, u1-snrnp 45%, rnp70 45% , pcna highly sensitive if highly elevated )
Name 1 nuclear antigens that are diagnostic for mctd (mixed)
U1 - snrnp (overlap sle/scl/pm)
Name 2 nuclear antigens that are diagnostic for polymyositis pm
• Jo-1 (30 %)
• speckled Ana pattern!
Mi-2 helps, pm - scl for polymyositis/scleroderma overlap syndrome
Name nuclear antigens that are diagnostic for progressive systemic sclerosis
Scl-70 (topoisomerase 1) (70%)
Fibrillarin exclusively identifies systemic sclerosis
What does a CtD screen consist of
Cocktail of 18 associated extractible nuclear antigens
(Negative if <0,7 ratio)
Name 2 nuclear antigens that are diagnostic for crest syndrome
Centromere p (90%)
Cenp
Name nuclear antigens that are diagnostic for neuropsychiatric SLE
Ribosomal p
Name 2 nuclear antigens that are diagnostic for scleroderma
• cenp (>90%) ‘
• Ana pattern: centromere antibodies!
Fibrillarin helps, pm -scl for polymyositis/scleroderma overlap syndrome
Serodiagnosis of rheumatoid arthritis? (2)
• Rheumatoid factor (75-82%): higher = more severe
• anti CCP antibodies (anti cyclic citrullinated peptide, 80-92 %): present years before clinical onset
Name 3 symptoms anti-phospholipid syndrome
• A/v thrombosis
• recurrent fetal loss/ iugr
• thrombocytopenia
Name 5 risk factors anti-phospholipid syndrome
• Female
• pre-existing inflammatory disorders
• cigarette
• hyperlipidaemia
• ht
Which autoantibodies are found in anti phospholipid syndrome (2)
• Anti-cardiolipin antibodies (acla): igG, IgA (esp Africans), IGM
• antibodies to beta 2 glycoprotein 1 (associated with thrombosis and foetal loss)
Inhibit thrombin activation protein c, inhibit degradation of factor V byprotein S, bind to vascular endothelium causing complement activation and thromboxane generation, bind to decidual tissue causing complement activation and generation of TNF (this causes the pregnancy loss)
Interpret results syphilis serology:
RPR 1:4, tpha negative, igG negative, IgM negative
Negative disease
Interpret results syphilis serology:
RPR 1: 64, tpha positive, igG very high, IgM negative or positive
Positive syphilis
Interpret results syphilis serology:
RPR neg/nr, tpha positive, igG high, IgM high
Positive for syphilis
Interpret results syphilis serology:
RPR neg/nr, tpha negative, igG negative, IgM negative
Negative
Interpret results chlamydia serology:
igG 1:128 high, IgM 1:20 high , IgA 1:16 normal
Acute infection
IgA = chronic marker
Interpret results chlamydia serology:
igG 1: 512 very high, IgM negative , IgA 1: 64 high
Severe untreated acute infection
Interpret results chlamydia serology:
igG 1: 64 borderline high, IgM negative , IgA negative
Borderline, treat based on clinical picture
Interpret results rickettsia serology:
igG 1:128 high, IgM 1: 64 borderline high
Active acute tick bite fever
Interpret results rickettsia serology:
igG 1: 152 very high, IgM negative
Chronic tick bite fever
Interpret results rickettsia serology:
igG negative, IgM negative
Negative for tick bite fever
Interpret results rickettsia serology:
Phase 2 igG 1: 512 very high, Phase 1 igG negative, phase 2 IgM 1: 256 very high, phase 1 IgM 1: 64 borderline high
Phase 2> phase 1 therefore acute tick bite fever
Interpret results rickettsia serology:
Phase 2 igG 1: 128 high, Phase 1 igG 1: 128 high, phase 2 IgM negative, phase 1 IgM 1: 512 very high
Phase 1 > phase 2 therefore chronic tick bite fever
Diagnosis rheumatoid arthritis? (2)
- Rheumatoid factor (>400 = severe)
- anti - ccp antibodies (present before onset)
