sensitive marker of disease activity in patients with systemic lupus erythematosus: serum neopterin

ABSTRACT

Serum neopterin was assayed in 24 patients with systemic lupus erythematosus [SLE] under various treatment modalities with variable control and compared to 10 healthy age-sex matched volunteers. Patients were followed up for a duration of six months for any evidence of disease activity and were restudied during the earliest disease exacerbation. Serum C3, C4 and circulating immune complexes [CIC] were also assayed as well as ESR as markers of disease activity. C-reactive protein [CRP] was estimated initially and during the disease exacerbation to rule out infections. Patients with positive CRP were excluded from the study. Serum neopterin was significantly elevated among patients when compared to controls. Neopterin level seemed to be a supersensitive marker of disease activity correlating firmly with CIC and with the consumption of C3 predicting early relapse of lupus activity even before the drop of C3. It neither correlated with C4 nor with nonspecific parameters such as the erythrocyte sedimentation rate. Serum neopterin may serve as a supersensitive but nonspecific marker of disease activity in patients with SLE and if used in conjunction to specific markers, its prognostic value may be great