ABDOMINAL SCINTIGRAPHY USING TC-99M-HMPAO-LABELED LEUKOCYTES IN PATIENTS WITH SERONEGATIVE SPONDYLARTHROPATHIES WITHOUT CLINICAL-EVIDENCE OF INFLAMMATORY BOWEL-DISEASE

Abdominal scintigraphy with technetium-99m hexamethylpropylene amine o xime (Tc-99m-HMPAO)-labelled leucocytes is an excellent tool for evalu ating disease extent and activity of intestinal lesions in patients wi th inflammatory bowel disease (IBD). In some cases of seronegative spo ndylarthropathies (SSp), IBD may remain subclinical. The aim of this s tudy was to evaluate the presence of positive abdominal scintigraphy i n patients with SSp and without clinical symptoms or signs of IBD, To this end we studied 32 patients with active SSp (European Spondylarthr opathy Study Group 1991 criteria) without clinical evidence of IBD (ei ght had ankylosing spondylitis, four psoriatic arthritis, three reacti ve arthritis an 17 undifferentiated SSp) and 11 controls without SSp. All SSp and control patients received similar doses of non-steroidal a nti-inflammatory drugs (NSAIDs), Abdominal scintigraphic images were o btained at 30 and 120 min after re-injection of Tc-99m-HMPAO-labelled leucocytes. The Tc-99m-HMPAO-labelled leucocyte scan was positive in 1 7 patients with SSp (53.1%) (six with ankylosing spondylitis, three wi th psoriatic arthritis, two with reactive arthritis and six with undif ferentiated SSp). Fourteen patients scored from 2 to 4 on the intensit y of uptake scale. The colon and terminal ileum were predominantly inv olved. Axial involvement was more frequent in patients with a positive scan than in patients with negative results (P < 0.05) (64.7% vs 26.6 %; odds ratio: 5). No control patient showed a positive scan. It is co ncluded that Tc-99m-HMPAO-labelled leucocyte scan shows increased upta ke among patients with SSp without evidence of IBD. These findings pro vide new evidence linking SSp with intestinal inflammation and suggest that in some cases a bowel-related process could contribute to the de velopment of SSp. Longterm follow-up studies with more patients are ne cessary to evaluate the diagnostic and therapeutic implications of the se results.