Autoimmune diseases

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  • 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 

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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

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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

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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

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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)

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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

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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

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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)

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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

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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

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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

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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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Comments

Jane4455

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An autoimmune disease is a condition in which your immune system mistakenly attacks your body. I know well as I have multiple sclerosis. Though this is no cure, there are medications like tecfidera that can slow the process down. I hope one day this disease will be completely treatable. Anyway, thanks for the good info.

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