Systemic Autoinflammatory Syndromes — DCE Clinical Case

Long Case — Familial Mediterranean fever with AA amyloidosis

Patient scenario

Mr Yusuf Demir is a 28-year-old carpenter of Turkish ancestry who presents to the outpatient clinic after proteinuria was found on a routine insurance medical examination. [1]

History of presenting complaint: [1]

• Twelve-year history of recurrent attacks of fever and severe abdominal pain. Each attack begins abruptly with fever reaching 39 degrees Celsius, followed within hours by severe diffuse abdominal pain with nausea. The attacks last one to two days and resolve completely, leaving him entirely well. They occur every 4 to 8 weeks.
• At age 20 he had a laparotomy during an attack that showed a normal appendix; the appendix was removed but the pain recurred within months.
• He describes an erysipelas-like rash on his lower legs during some attacks — a tender, warm, red rash below the knee.
• He occasionally has pleuritic chest pain during attacks.
• Proteinuria was detected on the insurance medical; he has no oedema, no haematuria, and his renal function was previously normal. [1]

Past medical history: Appendicectomy at age 20 (normal appendix). No previous autoimmune disease. No asthma or atopy. [1]

Medications: None regular. Paracetamol and NSAIDs during attacks. [1]

Family history: Father died of renal failure at age 45 of unknown cause. One sister (age 25) describes occasional episodes of abdominal pain and fever. Paternal uncle in Turkey with a history of recurrent abdominal pain. [1]

Social history: Married, no children yet. Works as a carpenter. Non-smoker, minimal alcohol. Migrated to Australia from Turkey at age 8. [1]

Examination findings: [1]

• Afebrile and well-appearing between attacks. Heart rate 72, blood pressure 132/84.
• Abdomen: midline laparotomy scar, soft and non-tender. No organomegaly.
• Skin: no active rash. Faint brownish discoloration on the lower shins consistent with old erysipelas-like lesions.
• Joint examination normal. No oral or genital ulceration.
• Cardiovascular, respiratory and neurological examination normal. [1]

Investigations: [1]

Candidate's opening statement (model answer — SASPOP format)

"Mr Yusuf Demir is a 28-year-old carpenter of Turkish ancestry presenting with a 12-year history of familial Mediterranean fever — recurrent attacks of fever and serositis lasting one to two days, with a previous negative laparotomy at age 20 — now complicated by AA amyloidosis with an albumin-to-creatinine ratio of 280 and a creatinine of 130. [1]

He is of Turkish ancestry with a family history strongly suggestive of FMF — his father died of renal failure at 45 (likely AA amyloidosis from undiagnosed FMF), a sister has similar abdominal attacks, and a paternal uncle in Turkey is affected. His serum amyloid A is elevated even between attacks, indicating persistent subclinical inflammation. [1]

My problem list is: (1) familial Mediterranean fever, undiagnosed for over a decade; (2) AA amyloidosis with proteinuria and early chronic kidney disease; (3) a colchicine initiation and titration plan aimed at complete attack prevention and amyloidosis arrest; (4) genetic confirmation with MEFV testing and cascade family testing; (5) the psychosocial impact of a delayed diagnosis and a preventable complication; and (6) the implications for his siblings, his father's family, and his future children. [1]

This is a chronic disease with effective treatment. My immediate management is to start colchicine 1.5 mg daily, confirm the diagnosis with MEFV genetic testing and a renal biopsy for AA amyloidosis, and arrange genetic counselling for the family." [1]

Integrated management plan

1. Familial Mediterranean fever (undisciplined for over a decade) [1]

• Colchicine 1.5 mg orally daily (0.5 mg three times daily), titrated to the maximum tolerated dose that completely prevents attacks. The goal is zero attacks, because persistent subclinical inflammation drives amyloidosis [2].
• Patient attack diary to document response and guide titration.
• Avoid laparotomy for future attacks — counsel the patient and his general practitioner that the abdominal pain is serositis, not a surgical emergency, and that NSAIDs manage the acute attack.

2. AA amyloidosis with proteinuria and early chronic kidney disease [1]

• Nephrology referral for renal biopsy to confirm AA amyloidosis and stage the renal disease.
• Renoprotection with an ACE inhibitor or angiotensin receptor blocker for the proteinuria, with careful blood pressure and potassium monitoring.
• Serum amyloid A and urinalysis every 3 to 6 months — any rising serum amyloid A or worsening proteinuria mandates intensification of therapy. [1]

3. Colchicine initiation and titration [1]

• Start at 1.5 mg daily, increase to 2 mg daily if attacks persist, monitoring for gastrointestinal intolerance (diarrhoea) and myelosuppression.
• Reduce the dose in renal impairment given the creatinine of 130 and eGFR of 58.
• Drug interaction counselling — clarithromycin, statins and ciclosporin interact with colchicine and require dose adjustment or avoidance. [1]

4. Genetic confirmation and family testing [1]

• MEFV genetic testing to confirm the diagnosis (homozygous M694V is the most severe and amyloidosis-associated genotype).
• Clinical genetics referral for cascade family testing. The sister with abdominal attacks should be tested and offered colchicine prophylaxis. The father's death from renal failure is almost certainly AA amyloidosis from undiagnosed FMF.
• Carrier testing for the patient's partner before family planning, given the high carrier frequency in the Turkish population (approximately 1 in 5). [1]

5. Cytokine-directed rescue strategy (if colchicine-resistant) [1]

• Canakinumab 150 mg subcutaneously every 8 weeks is the evidence-based IL-1 blocker for colchicine-resistant FMF, approved on the basis of the CLUSTER trial [3]. Indicated if the patient does not achieve complete attack control on the maximum tolerated colchicine dose, or if the amyloidosis progresses despite colchicine.

6. Psychosocial support [1]

• Clinical psychology referral for the impact of a delayed diagnosis, a preventable complication, and the grief surrounding his father's likely preventable death.
• Patient education on the colchicine contract — adherence is the single biggest determinant of long-term renal outcome.
• Support for family planning decisions and genetic counselling. [1]

Communication and shared decision-making

• Frame the diagnosis as a genuine lifelong condition with effective treatment — the shift from recurrent unexplained attacks to a named, treatable diagnosis is therapeutic.
• Explain the colchicine contract honestly: the goal is complete attack prevention and amyloidosis prevention, not just fewer attacks. Adherence is non-negotiable for renal preservation.
• Address the grief and anger surrounding his father's death — that renal failure was almost certainly AA amyloidosis from undiagnosed FMF, and is now preventable with colchicine. This reframes the diagnosis as an opportunity to spare his siblings and future children.
• Discuss the genetic implications for his sister (who should be tested and offered prophylactic colchicine) and for his future children (carrier testing of his partner before conception). [1]

Probing questions and model answers

Examiner: What is the significance of the elevated serum amyloid A between attacks? [1]

"An elevated serum amyloid A between attacks indicates persistent subclinical inflammation — the patient is not truly well between attacks biochemically, even if he feels well clinically. This is the substrate for AA amyloid deposition: serum amyloid A is an acute phase reactant that, when chronically elevated, misfolds and deposits as AA amyloid in the kidney, heart and gut. The goal of colchicine therapy is not just to prevent clinical attacks but to normalise the serum amyloid A, because subclinical inflammation drives the amyloidosis. I would monitor the serum amyloid A at every visit and titrate colchicine to a normal value, escalating to canakinumab if the serum amyloid A remains elevated despite the maximum tolerated colchicine dose." [1]

Examiner: Why did the laparotomy not help, and what does that tell you? [1]

"The laparotomy did not help because the abdominal pain was peritonitis from familial Mediterranean fever, not a surgical pathology — the appendix was normal. FMF attacks cause severe diffuse abdominal pain with guarding and rigidity that perfectly mimics an acute surgical abdomen, which is why FMF patients accumulate unnecessary laparotomies and appendicectomies before diagnosis. The lesson is that any patient of Mediterranean ancestry with recurrent self-limiting attacks of abdominal pain and fever, particularly with a prior negative laparotomy, should be assessed for FMF before further surgical intervention. The episodic, self-limiting nature and the full inter-attack wellness are the clues that distinguish FMF from a surgical abdomen." [1]

Examiner: What is the prognosis with treatment? [1]

"With complete attack prevention on colchicine, the prognosis is excellent — further AA amyloid deposition is halted, and existing renal function is preserved. The challenge is that Mr Demir already has early chronic kidney disease (eGFR 58) and significant proteinuria (albumin-to-creatinine ratio 280), so some of the amyloid damage is established and may not fully reverse. Renoprotection with an ACE inhibitor and tight blood pressure control will help preserve function. [1]

The broader prognostic point is the family — his sister should be tested and, if affected, started on prophylactic colchicine before she develops amyloidosis, which is entirely preventable with early treatment. His father's death from renal failure was almost certainly preventable AA amyloidosis, which underscores the importance of early diagnosis and lifelong colchicine adherence in this family." [1]

Short Case — Skin examination: a chronic urticarial rash

Examination instruction

"Examine this patient's skin, then present your findings and discuss the differential of a chronic urticarial rash in the context of autoinflammatory disease." [1]

Systematic examination routine

Step 1 — Inspect at the end of the bed:

• General appearance — chronic illness, distress, obvious skin lesions, hearing aids. [1]

Step 2 — Examine the rash:

• Describe the urticarial lesions — distribution (trunk, limbs, face), morphology (wheals, plaques), whether they are continuous or episodic, whether they leave bruising or pigmentation, whether they are cold-induced.
• Check for the neutrophilic urticarial dermatosis pattern — lesions that are more persistent (over 24 hours) and leave faint bruising suggest neutrophilic urticarial dermatosis (CAPS, Schnitzler) rather than ordinary mast-cell urticaria. [1]

Step 3 — Examine for syndrome-specific signs:

• Hearing aids or cochlear implants — Muckle-Wells syndrome (progressive sensorineural hearing loss).
• Joint deformity and bony overgrowth at the knees — NOMID/CINCA (central epiphyseal overgrowth).
• Hepatosplenomegaly and lymphadenopathy — AOSD, macrophage activation syndrome.
• Periorbital oedema — TRAPS.
• Oral and genital ulceration — Behcet disease.
• Erysipelas-like rash on the lower legs — FMF. [1]

Step 4 — Examine for complications:

• Pitting oedema and hypertension — AA amyloid nephropathy.
• Digital clubbing and papilloedema on fundoscopy — NOMID with chronic raised intracranial pressure. [1]

Key physical signs this patient demonstrates

• Chronic urticarial rash present continuously since infancy on the trunk and limbs — neutrophilic urticarial dermatosis on biopsy.
• Bilateral hearing aids — progressive sensorineural hearing loss.
• No oral or genital ulceration, no arthritis, no periorbital oedema — points away from Behcet, AOSD and TRAPS. [1]

Presentation template

"This patient has a chronic urticarial rash present since infancy, with bilateral hearing aids indicating progressive sensorineural hearing loss. The combination of chronic urticaria and progressive sensorineural hearing loss, with onset in infancy, is characteristic of Muckle-Wells syndrome, a cryopyrin-associated periodic syndrome caused by a gain-of-function mutation in NLRP3. [1]

I would confirm with NLRP3 genetic testing, a skin biopsy to demonstrate neutrophilic urticarial dermatosis (perivascular neutrophils without vasculitis, distinguishing it from ordinary mast-cell-driven urticaria), and baseline urinalysis and serum amyloid A to screen for AA amyloidosis. The treatment is canakinumab 150 mg subcutaneously every 8 weeks, an interleukin-1 beta blocker that halts further hearing loss and prevents amyloidosis." [1]

Discussion questions

Examiner: What is the differential of a chronic urticarial rash in the autoinflammatory context? [1]

"The differential of a chronic urticarial rash with systemic features includes: the cryopyrin-associated periodic syndromes (CAPS — FCAS, Muckle-Wells, NOMID), all NLRP3-driven with neutrophilic urticarial dermatosis; Schnitzler syndrome (chronic urticaria plus monoclonal IgM gammopathy in an older adult); adult-onset Still disease (evanescent salmon-pink rash with spiking fever); ordinary chronic spontaneous urticaria (mast-cell-driven, negative systemic features, no paraprotein, normal biopsy); and urticarial vasculitis (lesions lasting over 24 hours with residual bruising, leukocytoclastic vasculitis on biopsy). The skin biopsy and serum electrophoresis are the two tests that most rapidly discriminate: neutrophilic urticarial dermatosis points to CAPS or Schnitzler, leukocytoclastic vasculitis to urticarial vasculitis, and a monoclonal IgM to Schnitzler." [1]

Examiner: How does the pathophysiology of CAPS explain the treatment? [1]

"CAPS is caused by gain-of-function mutations in NLRP3, encoding cryopyrin, a component of the NLRP3 inflammasome. The mutant inflammasome is constitutively active, continuously cleaving pro-interleukin-1 beta to active interleukin-1 beta via caspase-1. The excess interleukin-1 beta drives the urticaria, fever, hearing loss and amyloidosis — it is the single dominant cytokine. [1]

This explains the dramatic response to interleukin-1 blockade. Canakinumab, a monoclonal antibody against interleukin-1 beta, produces rapid and sustained remission with normalisation of inflammatory markers and prevention of hearing loss progression — it is the prototypical transformative targeted therapy. Anakinra, a recombinant interleukin-1 receptor antagonist, and rilonacept, an interleukin-1 trap, are alternatives that block the same pathway. The key clinical point is that the hearing loss is irreversible once established, so interleukin-1 blockade must be started early, not after the hearing loss has progressed." [1]

Examiner: What is the autoinflammatory-versus-autoimmune distinction, and why does it matter? [1]

"Autoinflammatory disease is driven by excessive activation of innate immune pathways — inflammasomes and the cytokines they release, chiefly interleukin-1 beta — without high-titre autoantibodies or antigen-specific lymphocyte responses. Autoimmune disease, in contrast, is driven by loss of adaptive immune tolerance, with autoreactive T cells and high-titre autoantibodies such as anti-dsDNA or ANCA. [1]

The distinction matters for three reasons. First, the autoantibody screen is typically negative in autoinflammatory disease, so a negative ANA, ANCA and rheumatoid factor in a patient with recurrent systemic inflammation points toward an autoinflammatory rather than autoimmune process. Second, the treatment targets cytokines rather than lymphocytes — interleukin-1 blockade for CAPS, HIDS, TRAPS, colchicine-resistant FMF, AOSD and Schnitzler, rather than B-cell depletion or T-cell modulation. Third, many autoinflammatory diseases are hereditary, so genetic testing and family counselling are part of the workup, which is rare in acquired autoimmune disease." [1]