Potential of 18 F-FDG-PET as a valuable adjunct to clinical and response assessment in rheumatoid arthritis and seronegative spondyloarthropathies

Table 1 Characteristics of patients included in the study

No.	Characterstics	Ankylosing spondylitis	Psoariatic arthritis	Non specific SSA	Rheumatoid arthritis
1	Total number of patients	7	3	1	17
2	Male: female ratio	All male	2:1	Male	All female
3	Age range	17-40 yr (mean = 28.6 yr)	34-53 yr (mean = 42 yr)	19 yr	27-60 yr (mean = 40 yr)

SSA: Seronegative spondyloarthropathy; M: Male; F: Female.

Table 2 Clinical and laboratory parameters adjudged for inclusion and exclusion of each patient and designating them to a particular group

Inclusion criteria

Positive ACR criteria[8-10] (at least 4 out of 7) for designating RA

Clinical diagnosis of specific seronegative spondyloarthropathy1

Positive or negative RA factor

Classical symptoms with raised ESR (> 30 mm/h)

Classical symptoms with raised C-reactive protein (> 20 mg/L)

HLA-B27 positive with supportive clinical diagnosis1

Newly diagnosed and not received any form of treatment.

Exclusion criteria

Had been treated with any DMARD/steroids earlier.

Uncontrolled diabetics

¹Clinical diagnosis was based upon thorough clinical assessment. ACR: American College of Rheumatology; RA: Rheumatoid arthritis; ESR: Erythrocyte sedimentation rate; HLA: Human leukocyte antigen; DMARD: Disease modifying anti-rheumatoid drugs.

Table 3 The erythrocyte sedimentation rate and C-reactive protein characteristics of studied patients

Type of RD	No. of patients	ESR range (mm/h)	CRP levels (mg/L)
RA	17	< 10 to 640	< 5 to 46.14
AS	7	30 to 92	< 5 to 20
PsA	3	27 to 30	20 to 29
nsSSA	1	31	23.1

RD: Rheumatic disorder; ESR: Erythrocyte sedimentation rate; CRP: C-reactive protein; RA: Rheumatoid arthritis; AS: Ankylosing spondylitis; PsA: Psoriatic arthritis; nsSSA: Non-specific seronegative spondyloarthropathy.

Table 4 Response details in patients with rheumatoid arthritis: Fluorodeoxyglucose positron emission tomography vs clinical assessment

Sr. No.	No. of joints involved	Clinical assessment	% change in SUVmax
1	10	Mixed symptoms	Knee = 64% ↓
			Ankle = no change
			Wrist = 51.7% ↑
			Elbow = 47% ↓
2	4	Progressive disease	Knee = 44% ↑
			Ankle = 33% ↑
3	2	Improvement	Wrists = 62% ↓
4	6	Improvement	Ankle = 23% ↓
			Wrist = 45.2% ↓
5	4	Improvement	Wrist = 73 % ↓
			SJH* = 34% ↓
6	6	Improvement	Ankle = 43.3% ↓
			Wrists = 23 % ↓
			SJF* = 24.5% ↓
7		No response	No change
8		No response	No change
9	2	Progressive disease	Wrists = 48% ↑

SUVmax: Maximum standardized uptake value; SJF: Small joints of foot; SJH: Small joints of hand.