Microheterogeneity of acute-phase glycoproteins in patients with pulmonary sarcoidosis

Abstract

M Mi ic cr ro oh he et te er ro og ge en ne ei it ty y o of f a ac cu ut te e--p ph ha as se e g gl ly yc co op pr ro ot te ei in ns s i in n p pa at ti ie en nt ts s w wi it th h p pu ul lm mo on na ar ry y s sa ar rc co oi id do os si is s The glycosylation profile of AGP and ACT was studied using affinity immunoelectrophoresis with the lectin concanavalin A (conA). Serum concentration of soluble receptor for interleukin-2 (sIL-2R) and activity of serum angiotensin converting enzyme (ACE) were measured by specific enzyme-linked immunosorbent assay (ELISA) and enzyme kinetic assay, respectively. Rocket immunoelectrophoresis and nephelometric assay were used to determine serum concentration of AGP, ACT and C-reactive protein (CRP).In 11 patients with active disease, a decreased reactivity of AGP with conA was found as compared with controls (n=44) and patients with nonactive sarcoidosis (n=26). A similar tendency was seen with ACT. In the same group, increased concentrations of serum AGP and higher levels of sIL-2R were detected compared with patients with nonactive sarcoidosis. In the entire sarcoidosis group, there was a negative correlation between ACE activity and AGP and ACT affinity for conA (r= -0.6358, and r=-0.5019, respectively) and a positive correlation with sIL-2R level (r=0.8241). In nine patients with elevated concentrations of serum CRP, no differences were found in disease activity and glycosylation profile of AGP and ACT when compared to patients with normal serum CRP.The results suggest that in active pulmonary sarcoidosis changes in the glycosylation pattern of acute-phase glycoproteins exist, which are similar in trend and magnitude to those found in other chronic inflammatory diseases. The synthesis and glycosylation of acute-phase proteins in pulmonary sarcoidosis are probably regulated independently. Eur Respir J., 1996, 9, 313-318

Association of fatigue with an acute phase response in sarcoidosis

“…Increased CRP production is a nonspecific response to most forms of tissue inflammation [21, 22]. Hepatocytes have been identified as the site of origin of acute phase proteins such as CRP.…”

Serum amyloid A and high‐density lipoprotein cholesterol: serum markers of inflammation in sarcoidosis and other systemic disorders

“…Serum KL‐6, a mucinous high‐molecular weight glycoprotein expressed on type II pneumonocytes, is elevated in patients with active pneumonitis in pulmonary sarcoidosis [65]. In active pulmonary sarcoidosis, changes in the glycosylation pattern of acute‐phase glycoproteins, α1‐acid glycoprotein and α1‐antichymotrypsin exist [66]. The serum concentration of ionized calcium has also been considered to be a useful index for the disease activity of sarcoidosis [67].…”

Acute Phase Proteins: Structure and Function Relationship

“…Conversely, a shift in the population of APPs towards those with a higher content of conA-nonreactive tri-and tetra-antennary carbohydrates has been shown in the sera of patients with chronic inflammatory diseases (e.g. chronic bacterial infections, rheumatoid arthritis, ankylosing spondylitis) (Hrycaj et al, 1996;Stibler et al, 1998). An intriguing question is whether the changes in the glycosylation profile of APPs might affect their biological activity and/or function.…”