Autoimmune diseases
- Created by: MazzaW
- Created on: 12-11-19 10:34
Rheumatoid arthritis
RFs: smoking, HLA DR4/DR1, female, age 30-50
Presentation: swollen joints, joint pain, early morning stiffness, affects MCPs/MTPs, symmetrical, muscle wasting, progressive deformity, improvement with anti-inflammatories
Extra-articular features: eyes, lungs (fibrosis), rheumatoid nodules, skin (ulcers, rash, nail fold infarcts), abnormal LFTs, CVS problems, thyroid disorders, neuropathy
Ix: clinical Dx, also rheumatoid factor + anti-CCP antibodies (more specific), Xray hands + feet
Nonspecific Ix: ESR, CRP, FBC (normocytic anaemia, inflammatory changes), LFTs, ANA (+ve in SLE + sometimes in RA), may have microscopic haematuria + proteinuria (suggests CT disease)
Mgmt: refer to specialist (needs MDT care), NSAIDs, monitor DAS28 while initiating treatment, simple analgesics, steroids for flare-ups, early initiation of DMARDs (methotrexate, sulfasalzine)
Complications: depression, impact on work/QOL, other autoimmune disease, high infection risk
SLE
RFs: female, HLA DR2/DR3, UV light/EBV/some drugs
Presentation: relapsing and remitting, often nonspecific Sx (fatigue, malaise, fever, splenomegaly, lymphadenopathy, wt loss etc), any major organ involvement tends to occur within 5yrs
Other features: joint pain/early morning stiffness, fibromyalgia, mild Raynaud's, malar rash (spares nasolabial folds)/discoid rash (sun-exposed areas), mouth ulcers, pulmonary/CVS involvement, asymptomatic nephritis (microscopic haematuria/proteinuria, HTN, raised urea/creatinine), neuro manifestations, anxiety/depression
Ix: urinalysis (protein/blood), FBC (normocytic anaemia/haemolysis, mild pancytopenia), raised ESR, positive ANA (sensitive but not specific), anti-Sm (specific but not sensitive), anti-dsDNA (specific but not sensitive), monitor CVS RFs, other Ix depend on system involvement
Association with antiphospholipid syndrome (and other autoimmune diseases)
Mgmt: symptom relief (NSAIDs and simple analgesia), if this is inadequate consider steroids/ hydroxychloroquine/cyclophosphamide
Antiphospholipid syndrome
Diagnostic criteria:
- clinical: 1+ episode of arterial/venous/small vessel thrombosis, pregnancy morbidity (1+ unexplained fetal death after 10 wks, 1+ unexplained preterm birth before 34 wks, 3+ unexplained consecutive spontaneous miscarriages before 10 wks)
- lab: lupus anticoagulant present in plasma on 2+ occasions 12 wks apart, anticardiolipin present in medium-high titres in plasma/serum on 2+ occasions 12 wks apart, anti-b2-glycoprotein I present in plasma/serum on 2+ occasions 12 wks apart
RFs: SLE (present in 30% SLE pts), female, fertile, black, familial, autoimmune disease
Presentation: thrombosis (any kind), pregnancy problems (miscarriage, preterm, pre-eclampsia, IUGR), thrombocytopenia, haemolytic anaemia, nephropathy, livedo reticularis, valve disease
Ix: levels of aCl/LA/anti-b2-GPI (12 wks apart), FBC, coag screen, CT/MRI brain/chest/abdomen (?CVA/PE/Budd-Chiari syndrome) or Doppler US (?DVT), echo (?valve disease)
Mgmt: reduce CVS RFs, close monitoring in pregnancy, watch out for thrombosis
Goodpasture's
Caused by type 2 Ab-Ag reaction with circulating anti-GBM Abs. Most common cause of pulmonary-renal syndrome (acute glomerulonephritis + alveolar haemorrhage)
RFs: HLA DRB1, smoking, male, exposure to pulm. irritants (solvents, metal dusts)
Sx: fever, N+V, anaemia, haematuria, AKI, fluid overload, tachypnoea, inspiratory crackles (lung bases), cyanosis, HTN
Ix: FBC, urinalysis (blood, some protein, RBC casts), U+Es, ESR (should be normal- raised in vasculitis), anti-GBM Abs (diagnostic), ANA, complement, ANCA, CXR, may have restrictive spirometry, renal biopsy
Mgmt: remove circulating Abs by plasmapheresis, immunosuppression to prevent further Ab production (steroids), may require RRT/transplant if in end-stage renal failure
Complications: pulm haemorrhage + resp failure, end-stage renal failure, infection, relapse
Type 1 diabetes mellitus
Insulin autoAbs destroy beta cells leading to absolute insulin deficiency. Associated with HLA DR3/DR4
Presentation: usually preschool/early teenagers, polydipsia, polyuria, wt loss, malaise, lethargy, dehydration, usually acute with short duration of Sx
May present in DKA: ketoacidosis, ketonuria, dehydration, Kussmaul's breathing, drowsiness, coma
Dx: 1 plasma glucose >11 (random) or >7 (fasting) in presence of Sx, 2 abnormal fasting glucoses if no Sx, HbA1c > 48
Mgmt: education, diet and lifestyle, hypo awareness, insulin therapy, HBGM, MDT involvement, reducing CVS RFs, monitoring for complications
Complications: nephropathy, retinopathy, neuropathy, macrovascular (MI, CVA)
Graves disease
Abs stimulate TSH receptor resulting in hyperthyroidism
Presentation: exophthalmos, lid lag, ophthalmoplegia, proximal muscle wasting, tremor, palpitations, wt loss, anxiety, heat sensitivity, amenorrhoea, diarrhoea, sweating, palmar erythema, tachycardia, brisk reflexes, goitre, hair thinning, may present in thyrotoxicosis
RFs: female, adult, other autoimmune disease (PMH/FH)
Ix: TFTs, AMA, antithyroglobulin Abs, TSH receptor Abs (not widely available but best test), thyroid US, radioiodine thyroid uptake scan, CRP, ESR
Mgmt: usually destruction of thyroid gland (radiotherapy/surgery) followed by lifelong thyroid hormone replacement
Sjogren's
Lymphocytic infiltration of exocrine glands. Primary if occurs alone, secondary if occurs alongside other autoimmune conditions (usually RA, SLE, or scleroderma)
Sx: dry eyes (xerophthalmia), dry mouth (xerostomia), enlarged parotid glands
Ix: FBC usually normal, rheumatoid factor, ANA, may have positive antiphospholipid Abs, Schirmer test (nonspecific, just confirms presence of dry eyes), imaging/biopsy of salivary glands
Mgmt: symptom relief, avoid anticholinergic drugs, monitor for vasculitis + glomerulonephritis
PBC
Autoimmune destruction of intrahepatic ducts leading to intrahepatic cholestasis, scarring, fibrosis and cirrhosis
RFs: female, other autoimmune disease, caucasian, median age at Dx of 65
Presentation: may be asymptomatic (routine abnormal LFTs), fatigue, pruritus, RUQ pain, jaundice, often have Sjogren's, hepatomegaly, features of cirrhosis
Ix: raised ESR, raised ALP, rising bilirubin demonstrates progression, raised IgM, AMA (95%), may also have ANA, TFTs, may need liver biopsy
Mgmt: UCDA, avoid exogenous oestrogen, symptom relief, liver transplant (later stages)
PSC
Autoimmune inflammation and fibrosis of intra and extrahepatic ducts
RFs: male, median age at Dx of 35, associated with IBD
Presentation: often asymptomatic (routine abnormal LFTs or hepatomegaly), jaundice, pruritus, RUQ pain, fatigue, wt loss, fevers, hepatosplenomegaly, may present with complications
Assess severity with Child-Turcotte-Pugh scale: grade of encephalopathy, presence/absence of ascites, serum albumin, PT, bilirubin
Ix: LFTs (raised ALP/GGT), raised IgG/IgM, may have positive p-ANCA/ANA/aCl, US (1st line), MRCP, liver biopsy (only for staging)
Mgmt: symptom relief, nutritional support, liver transplant
Complications: biliary obstruction (stones/strictures), cirrhosis, ascites, portal HTN, oesophageal varices, cholangiocarcinoma, colorectal Ca
Autoimmune hepatitis
Autoimmune hepatocellular inflammation and necrosis, tends to progress to cirrhosis
RFs: typically affects young and middle-aged women, associated with other autoimmune disease
Presentation: fatigue, myalgia, pruritus, nausea, upper abdo discomfort, anorexia, diarrhoea, arthralgia, rash, hirsutism, oedema, amenorrhoea, pleuritis, wt loss, hepatosplenomegaly, jaundice, spider naevi, ascites, encephalopathy
Ix: raised ALT/AST, raised IgG positive autoAbs, raised IgG, liver biopsy (best diagnostic test)
Mgmt: immunosuppression (prednisolone + azathioprine), regular LFT monitoring, liver transplant (later stages)
Complications: hyperviscosity (due to raised IgG), HCC, Cushing's syndrome
Scleroderma
Multisystem autoimmunity causing fibrosis in skin, GI tract, heart, lungs and other organs
RFs: female, peak age of onset 40-50, Afro-Caribbean origin, other autoimmune disease
Presentation: fatigue, wt loss, calcinosis, swelling of digits, hard thickened skin (may limit mvmt), Raynaud's (90%), telangiectasia, itchy skin, 'salt and pepper' skin (areas of hypo and hyperpigmentation), joint pain and swelling, myalgia, heartburn and reflux oesophagitis, dysphagia, constipation, pulmonary fibrosis, pulmonary arterial HTN, cardiac changes, renal disease, erectile dysfunction
Ix: FBC, ESR, CRP, baseline biochemisty and renal function, autoAbs (antiScl 70, ACA, anti-RNA polymerase III Ab), hand Xray (calcinosis), monitoring organ function based on Sx
Mgmt: MDT, symptom relief, monitoring for complications, DMARDs
Behcet's disease
Multisystem autoimmune disease commonly presenting with recurrent oral ulcers
Presentation/Dx: recurrent oral ulcers + recurrent genital ulceration/eye lesions/skin lesions/ pathergy, can also affect CVS/GI/MSK/CNS systems
Ix (not diagnostic but can rule out DDx): FBC (mild anaemia, raised WCC), raised inflammatory markers, antiphospholipid Abs, pathergy test, angiography (assess aneurysms)
Mgmt: aim to prevent long-term damage, immunosuppresion, infliximab (TNF antagonist) may be useful, surgery for organ/system specific complications
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