Usefulness of procalcitonin for differentiation between activity of systemic autoimmune disease (systemic lupus erythematosus/systemic antineutrophil cytoplasmic antibody-associated vasculitis) and invasive bacterial infection

Abstract

Objective. To investigate whether the determination of serum procalcitonin (PCT) in systemic autoimmune disease will help to discriminate invasive infection from highly active underlying disease. Methods. Three hundred ninety‐seven serum samples, from 18 patients with systemic lupus erythematosus (SLE) and 35 patients with systemic antineutrophil cytoplasmic antibody‐associated vasculitis (AAV), were analyzed. Clinical disease activity was assessed by the Systemic Lupus Activity Measure in SLE patients and by the Birmingham Vasculitis Activity Score in AAV patients. Procalcitonin concentrations were determined in parallel with concentrations of neopterin, interleukin‐6 (IL‐6), and C‐reactive protein (CRP). Additionally, serum creatinine values were obtained. Results. In 321 of the 324 samples from the 42 patients with autoimmune disease but without systemic infection, serum PCT levels were within the normal range (i.e., <0.5 ng/ml), whereas the values for neopterin, IL‐6, and CRP were elevated in patients with active underlying disease. All 16 systemic infections occurred in 11 patients with AAV, and were associated with PCT levels that were markedly elevated, to a mean ± SD of 1.93 ± 1.19 ng/ml. No correlation between the degree of renal impairment and PCT concentrations was seen. Conclusion. PCT may serve as a useful marker for the detection of systemic bacterial infection in patients with systemic autoimmune disease.

Procalcitonin and C-reactive protein plasma concentrations in nonseptic uremic patients undergoing hemodialysis

“…In our study patients prior to undergoing their first hemodialysis, mean PCT plasma concentration was elevated (1.82±0.39 ng/ml) above the normal level of 0.5 ng/ml expected with normal renal function [15,16]. Two separate studies found plasma interleukin (IL-6) and tumor necrosis factor (TNF) α levels to be significantly higher in not yet dialyzed nonseptic end-stage renal failure patients than in normal individuals [17,18].…”

Procalcitonin and C-Reactive Protein Levels in Community-Acquired Pneumonia: Correlation with Etiology and Prognosis

“…In adult patients with sepsis, PCT determination is of high specificity and negative predictive value at a cut-off point of 0.5 µg/l [36]. This cut-off point is also useful for predicting systemic infections in patients with underlying active lupus erythematosus [37].…”

Urinary neopterin excretion and dihydropteridine reductase activity in rheumatoid arthritis

“…As described elsewhere, urine samples were diluted in 1 : 5 proportion with the [30,34] 3. Autoimmune diseases (a) Rheumatoid arthritis [24] (b) Systemic lupus erythematosus [35] (c) Sarcoidosis [30,36] (d) Familial mediterranean fever [37] (e) Crohn's disease [30] (f) Ulcerative colitis [30] (g) Wegener's granulomatosis [38] (h) Behçet's disease [17] (i) Thyroiditis [30] (j) Acute pancreatitis [39] (k) Multiple sclerosis [40] 4. Allograft rejection/graft vs host disease [41,42] 5.…”