Table 1

Summary of clinical features, investigations and treatments

		P1	P2	P3	P4	FDFFSDA P5
Demographics	Sex	M	F	M	M	F
	Current age	55	56	50	42 years	60 years
	Age at first presentation	35	53	Age 40 years—RA Age 49 years—autoinflammatory features	40 years	43 years
Autoimmune screen	ANA	−	−	−	−	−
	ACPA	+	+	+	+	−
	RF	+	+	−	+	Positive initially
	ANCA	-	−	Positive on one occasion, antimyeloperoxidase antibodies detected. Repeated ANCA have been negative on several occasions.	−	−
Genetic test	Shared epitope	DRB104:01 and 04:08	DRB1*01:01 homozygous	DRB104:01 and 04:04	DRB1*04:01 homozygous	DRB104:01 and 04:08
	NLRP3	c973C>T (pArg325Trp)	Nil	nil	Nil	Nil
	MEFV	Nil	c289C>T (pGln97*), c605G>A (pArg202Gln)	nil	Nil	Nil
	NOD2	Nil	Nil	c2722G>C (pGly908Arg)	c2104 C>T (pArg702Trp)	Nil
Other investigations	Highest CRP in the absence of infection (mg/l)	150	42	61	200	70
	Neutrophilia	Intermittently, during uncontrolled disease episodes	Intermittently	Yes, persistently raised	Yes, during acute flares	No
	X-ray	Mild erosive changes	Degenerative changes only		Normal, MRI showed inflammation	Degenerative changes, but no erosions
	Skin biopsy	Confirmed as lichen planus	Ulcerated epidermis with collections of neutrophils on the surface	Not done	Not done	Not done
Clinical features	Fevers	+	+	+	−	−
	Skin rash	+, confirmed as lichen planus on biopsy	+	Profound erythema at sites of synovitis	+	Erythema at sites of synovitis
	Arthritis	+	+	+	+	+
	Synovitis	+	+	+	+	+
	Serositis	-	Possible—one hospital episode with symptoms consistent with meningism. A lumbar puncture aspirate was sterile.	+ pericarditis, pleuritis (confirmed with echocardiogram and CT)	−	−
Treatment	Corticosteroids	Yes, good response	Yes, good response	Yes—good response	Yes—good response	Yes—partial response
	Colchicine	Yes, no response	Yes, partial response stopped due to side effects	Yes—good response	Yes—excellent response with normalisation of CRP	Yes—excellent clinical response
	Methotrexate	Yes, partial response, developed RA-like flare when stopped due to intolerance	Yes, good response	Yes—partial, stopped due to intolerance	Yes—partial response	Yes—partial response
	anti-TNF	Yes, response initially, but secondary non-response to etanarcept	No	No	No	No
	anti-IL-6	Yes, partial response, normalisation of CRP only	No	No	No	No
	anti-IL-1	Complete response to anakinra, although non-response to canakinumab	No	No	No	No
	Other			Hydroxychloroquine, sulfasalazine	Sulfasalazine—partial response	Sulfasalazine, hydroxychloroquine—partial response

ACPA, anticitrullinated protein antibody; ANA, antinuclear antibody; ANCA, antineutrophil cytoplasmic antibody; Nil, means that no rare variants were found in these genes; RA, rheumatoid arthritis; RF, rheumatoid factor.