Atypical Familial Mediterranean Fever in a Japanese Boy with Heterozygous MEFV p.Ser503Cys Exon 5 Variant

Table 1

Laboratory findings on admission.

WBC	5,460/μL	Na	137 mEq/L		Autoantibodies	Neg
NEU	78%	K	4.0 mEq/L
LYM	15%	Cl	98 mEq/L		M. pneumoniae -IgM	Neg
MONO	7%	Ca	9.1 mg/dL		EBV VCA-IgG	<10 1:n
RBC	498 × 10^4/μL	IP	4.6 mg/dL		EBV VCA-IgM	<10 1:n
Hb	13.7 g/dL	CRP	3.30 mg/dL		EBNA	160 1:n
Ht	40.9%	Procalcitonin	0.58 ng/mL	(<0.50)	CMV-IgG	Neg
PLT	27.9 × 10^4/μL	ESR (1 h)	43 mm		CMV-IgM	Neg
RET	1.2%	IgG	1,270 mg/dL		Coxiella burnetii-IgG (paired serum)	<64 1:n
AST	31 IU/L	IgA	228 mg/dL
ALT	25 IU/L	IgM	120 mg/dL
γ-GTP	14 IU/L	Ferritin	57 ng/mL	(21–282)	Urinalysis
LDH	231 IU/L	sIL-2R	498 U/mL	(122–496)	pH	6.5
CK	23 IU/L	ANA	<40 1:n		Red blood cell	Neg
T-BIL	0.3 mg/dL	CH50	64 U/mL		White blood cell	Neg
TP	7.5 g/dL	C3	205 mg/dL		Protein	Neg
Alb	4.0 g/dL	C4	51.7 mg/dL
BUN	20.0 mg/dL	RF	<15 U/mL
CRE	0.83 mg/dL	MMP-3	30.1 ng/dL	(37–121)
		SAA	920.0 μg/mL	(<8.0)
		Β-2 microglobulin	2.8 mg/L	(0.0–2.0)

sIL-2R, soluble interleukin-2 receptor; ANA, antinuclear antibody; RF, rheumatoid factor; MMP-3, matrix metalloproteinase-3; SAA, serum amyloid A; M. pneumoniae, Mycoplasma pneumoniae; EBV, Epstein–Barr virus; VCA, virus capsid antigen; EBNA, EBV nuclear antigen; CMV, cytomegalovirus; Neg, negative; (), normal range.