Excretion of neuraminic acid-containing trisaccharides in the urine during pregnancy

Isolation of Unusually Composed Sialyl-Compounds from Hemofiltrate

Sialyl compounds are essential components of various biological fluids but relatively little is known about their occurrence in the extracellular fluid of patients with end-stage renal disease. As we have developed a macropreparative method for concentrating and desalting a wide range of fractions from diluted biological fluids we have been able to isolate and identify 5 sialooligosaccharides, 3 sialosugarphosphates, 2 monosialoglycopeptides and 1 disialoglycopeptide. The structures have been elucidated predominantly by one and two-dimensional NMR spectroscopy, enzymatic degradation and FAB mass spectrometry.

The accumulation of these compounds in uremic sera may be of particular interest as they may interact in the molecular biology of diseases typically associated with the uremic state, e.g., immune deficiency, neurological disorders, receptor binding abnormalities, complement system disturbances and cell membrane alterations.

Relationship between urinary sialylated saccharides, serum amyloid A protein, and C-reactive protein in rheumatoid arthritis and systemic lupus erythematosus

The urinary excretion of sialic-acid-containing oligosaccharides, total sialic acid, serum amyloid A protein (SAA), and C-reactive protein (CRP) has been studied in 48 patients with rheumatoid arthritis (RA) and in 17 patients with systemic lupus erythematosus (SLE). Linear regression analysis revealed a close positive correlation between serum SAA and CRP levels in both RA (r = 0.71, p less than 0.001) and SLE (r = 0.86, p less than 0.001). The urinary excretion of sialyl lactose showed a positive correlation with the serum levels of SAA and CRP in RA (r = 0.45 and r = 0.45, respectively, p less than 0.01) but not in SLE (r = 0.05 and r = 0.10 respectively). Changes in serum total sialic acid levels paralleled those in CRP and SAA in RA as well as in SLE. Patients with very active RA had higher urinary sialyl oligosaccharide excretion (p less than 0.001), higher CRP levels (p less than 0.01), and higher SAA levels ( p less than 0.05) than those with moderately active disease.

Urinary sialyloligosaccharide excretion as an indicator of disease activity in rheumatoid arthritis

Urinary trisaccharides containing sialic acid, urinary total sialic acid, and serum sialic acid were studied in 51 patients with rheumatoid arthritis (RA). The urinary excretion of sialyllactose and sialyl-N-acetyllactosamine was measured by quantitative gas chromatography. The output of sialyllactose was significantly greater in patients with RA (31.9 +/- 17.3 mg/24, SD) than in control subjects (15.9 +/- 5.4, P less than 0.001). The RA patients also had higher mean levels of urinary sialyl-N-acetyllactosamine (P less than 0.05), total urinary sialic acid (P less than 0.001), and serum sialic acid (P less than 0.001). Urinary excretion of sialyllactose was considerably higher in patients with active and aggressive RA and moderately higher in patients with moderate disease activity. Excretion in those with mild or almost inactive RA did not differ significantly from that in the controls. Linear regression analysis revealed a strong positive correlation between urinary sialyllactose levels and clinical disease activity (P less than 0.001), as well as between excretion of sialyllactose and sialyl-N-acetyllactosamine in RA. These results suggest that the urinary content of trisaccharides containing sialic acid is an indicator of disease activity of RA.

Increased excretion of two sialic acid-containing trisaccharides in the urine of patients with rheumatoid arthritis

The urinary excretion of sialic acid-containing trisaccharides in patients with active rheumatoid arthritis was studied. Sialyl-lactose and sialyl-N-acetyllactosamine were identified and their excretion patterns studied by thin layer and gas chromatography. The urinary output of sialyl-lactose was greater in patients with active rheumatoid arthritis (48.2 +/- 6.1 mg/24 h, SEM, n = 6) than in healthy subjects (19.8 +/- 3.7 mg/24 h, SEM, n = 5; P less than 0.01). The excretion of sialyl-N-acetyllactosamine was also higher in the rheumatoid group (18.5 +/- 2.1 mg/24 h, SEM, n = 6) than in the controls (11.1 +/- 1.2 mg/24 h, SEM, n = 5; P less than 0.05). The qualitative excretion patterns of the sialyl-oligosaccharide fraction were similar for the two groups as judged from the thin layer chromatograms. Correlating the results with the clinical state of the patients with rheumatoid arthritis suggests that the urinary level of the sialyl-oligosaccharides reflects the activity of the disease. A proposed mechanism for the increased excretion of sialic acid-containing trisaccharides in rheumatoid arthritis is presented.