Speckled Pattern ANA target Antigens And Associated Diseases Flashcards
RANA
rheumatoid associated nuclear antigen
RA
Centromere (CENP)
limited cutaneous systemic sclerosis (sens 30%, spec 97%)
PBC
Jo-1
Which disease and which phenotype?
Polydermatomyositis
Associated with ILD, mechanics hands, and Raynaud’s phenomenon
Mi-2
Dermatomyosotis favourable long-term prognosis Steroid responsive "shawl sign" less cancer
RNP
ribonucleoprotein
MCTD (100%)
Specificity 84-100%
scl-70
Aka
Topoisomerase 1
systemic sclerosis- positive in 20% and is highly specific (100%) for diffuse disease
RARE to coexist with centromere Ab
Good to predict pulmonary fibrosis and developing diffuse cutaneous involvement
Sm
Smith antigen
SLE 30% sens
98% specific
SS-A
aka
Ro
Primary sjogrens 75% sensitive
SLE 35%
Secondary sjogren’s 15%
Presence is associated with developing extraglandular features in Sjogren’s (vasculitis, lymphadenopathy, nephritis, leukopaenia, photosensitivity, subacute cutaenous lupus, neonatal lupus and congenital heart block)
Pm-SCL
5% scleroderma alone
8% polymyositis alone
25% polymyositis/scleroderma overlap syndrome
SS-B
Aka
La
Sjogrens 60%
SLE 15%
rarely in other CTD
Not usually positive without ss-A
Anti ribosomal P protein antibodies
High specificity low sensitivity (10-20%) SLE
Associated with neuropsychiatric lupus
Anti RNP (anti ribonuclear protein)
95%-100% sensitivity MCTD
May also be high in SLE or Sjogrens
Sensitivity and specificity of ANA in SLE
Sensitivity: 95%
Specificity: 55%
Sensitivity and specificity of ANA in scleroderma
Sensitivity: 85%
Specificity: 55%
Sensitivity and specificity of ANA in polymyositits/dermatomyositis
Sensitivity 60%
Specificity 65%
Sensitivity and specificity of ANA in RA
Sensitivity 40%
Specificity 55%
Sensitivity and specificity of ANA in Sjogren’s
Sensitivity 50%
Specificity 50%
Use of ANA check in patient with Raynaud’s?
Estimate risk of developing an associated systemic rheumatic disease (19-30% with positive ANA, compared with 7% without ANA)
DNA- histone complex (nucleosome) associations
SLE (60%)
Drug induced lupus (95%)
ds DNA
SLE
57% sensitive
97% specific
present at some time in the course of the disease but fluctuate and may be absent
Also can be seen in RA, Sjogren’s, scleroderma, drug induced lupus, Raynaud’s, MCTD, myositis, chronic active hepatitis, uveitis, Grave’s, and in women with silicone breast implants.
Unless very high level of suspicion, do not check unless ANA elevated.
RNA polymerase types II and III
systemic sclerosis- low sens but highly specific
RNA polymerase 1, nucleolar RNA
systemic sclerosis- low sens but highly specific
Pm- scl
polymyositis/scleroderma overlap syndrome
anti- Th/To
Infrequent but specific for systemic sclerosis
List the autoantibodies against a group of aminoacyl tRNA synthetases in dermatomyositis and polymyositis
Jo1 PL-7 PL-12 EJ OJ
Rheumatoid factor
RA Sjogren's SLE systemic sclerosis Cryoglobulinaemia Dermatomyositis, polymyositis SBE Malignancy Infection (hepatitis, leprosy, parasites, syphilis, TB) Pulmonary disease (ALD, sarcoid, silicosis) Primary biliary cirrhosis
Sensitivity and specificity of RF in RA
Sensitivity 50-80%
Specificity 85-90% in advanced disease
Sensitivity and specificity of anti-CCP in RA
Sensistivity 30-60%
Specificity 95-98%
May be positive before disease emerges
May predict more rapid radiological progression
anti-Hu antibodies
limbic or brainstem encephalitis- small cell lung ca found in all of these if anti-Hu ab present.
Can also cause a subacute sensory neuropathy by attacking the DRG
anti Ma-2 antibodies
limbic encephalitis
associated with testicular cancer
respond well to immunosupressive therapy
anti-CRMP5
anti-CRMP5 encephalomyelitis
most common association is with SCLC and thymoma
cortical symptoms not often confined to the limbic system
anti NMDA receptor ab
anti NMDA receptor encephalitis
classical syndrome: psych manifestations, insomnia, memory deficits, seizures, dyskinesias, autonomic instability, language dysfunction including echolalia
Half of girls have an underlying ovarian teratoma. May not be associated with a tumour.
anti-LGI1 antibodies
not actually against voltage gated potassium channels as previously thought. Instead secreted neural protein that is a ligand for ADAM22 and 23 which are epilepsy proteins.
Memory disturbance, confusion, faciobrachial dystonic seizures, hyponatraemia
Anti-SRP
An ENA in necrotising myopathy
confers poor prognosis
Called Signal recognition protein
How do you interpret Complement testing?
Both low–>disease activity in lupus. Also 10% lupus patients are C4 deficient.
C4 lower than C3–>cryoglobulinaemia
Isolated C3 depression–>seen in membranoproliferative GN
Which is better in Lupus flares? CRP or ESR?
ESR
CRP is often normal in flares
HLAB27 associations?
Ank spond (strongest) Reactive arthritis Enteropathic spondyloarthritis Psoriatic Anterior uveitis Aortic incompetence with AV block
Normal in 5-8% caucasians
What is the role of HLAB27 testing in ank spond?
90% positive
inflammatory back pain in under 40s
absence of radiological changes eg early disease
Pos likelihood ratio 15
Scl-70
systemic sclerosis
40% in dcSSc
15% lcSSC
Increased risk pulmonary involvement but NOT severity
Reduced risk of renal involvement
RNA polymerase
Seen in 20% of systemic sclerosis
Associated with renal disease or severe skin disease
Can be used to assess risk of renal crisis in patients with early diffuse disease
Th/To
Poor outcome and pulmonary hypertension in lcSSc
PM-SCl
myositis scleroderma overlap
Centromere
60% limited cutaneous systemic sclerosis
less severe, better prognosis