Ultrasound detects subclinical joint inflammation in the hands and wrists of patients with systemic lupus erythematosus without musculoskeletal symptoms.

OBJECTIVES

To assess the prevalence and severity of ultrasonographic abnormalities of the hand and wrist of asymptomatic patients with systemic lupus erythematosus (SLE) and compare these findings with those from patients with SLE with musculoskeletal signs or symptoms and healthy controls.

METHODS

We conducted a prospective cross-sectional study that evaluated bilaterally, with grey-scale and power Doppler (PD) ultrasound (US), the dorsal hand (2nd to 5th metacarpophalangeal and 2nd to 5th proximal interphalangeal joints) and wrist (radiocarpal, ulnocarpal and intercarpal joints) of 30 asymptomatic patients with SLE, 6 symptomatic patients with SLE and 10 controls. Synovial hypertrophy (SH) and intra-articular PD signal were scored using semiquantitative grading scales (0-3). Individual scores were graded as normal (SH≤1 and PD=0) or abnormal (SH≥2 or PD≥1). Global indexes for SH and PD were also calculated. US findings were correlated with clinical and laboratory data and disease activity indexes.

RESULTS

US detected SH (score ≥1) in 77% asymptomatic patients with SLE, mostly graded as minimal (score 1: 63%). 23% of the asymptomatic patients with SLE showed abnormal US PD findings (SH≥2 or PD≥1). SH was present in all symptomatic patients with SLE, mostly graded as moderate (grade 2: 67%), and with associated PD signal (83%). SH (score 1) was identified in 50% of controls, however, none presented abnormal US PD findings. SH index in the asymptomatic SLE group was higher than in the control group (2.0 (0-5) vs 0.5 (0-2), median (range), p=0.01) and lower than in the symptomatic SLE group (7.0 (4-23), median (range), p<0.001). No significant correlation was demonstrated between US PD findings and clinical or laboratory variables and disease activity indexes.

CONCLUSION

A small subgroup of asymptomatic patients with SLE may present subclinical joint inflammation. Global US scores and PD signal may be important in disease evaluation and therapeutic monitoring.