Plasma fibronectin deficiency in Reye syndrome

Fibronectin in development and wound healing

Fibronectin structure and composition regulate contextual cell signaling. Recent advances have been made in understanding fibronectin and its role in tissue organization and repair. This review outlines fibronectin splice variants and their functions, evaluates potential therapeutic strategies targeting or utilizing fibronectin, and concludes by discussing potential future directions to modulate fibronectin function in development and wound healing.

Plasma fibronectin levels in extremely preterm infants in the first 8 weeks of life

Fibronectin has in the past been considered to function simply as a non-specific plasma opsonin. However, recent studies have demonstrated that this molecule plays an important role in fundamental components of the immune response, for example, neutrophil adhesion, T cell activation and endothelial function. Additionally, fibronectin is important in lung homeostasis where it contributes to alveolar epithelial integrity. In this study plasma fibronectin levels were measured longitudinally in a group of extremely preterm infants, mean gestational age 27 weeks. Plasma fibronectin levels at birth were significantly lower in the preterm study group than in term controls (mean 91 +/- 33 micrograms/mL compared with 214 +/- 62 micrograms/mL in the term controls, P < 0.0001). The preterm cohort demonstrated a more than two-fold rise in plasma fibronectin on days one and two; levels fell almost to baseline values by day three with a subsequent slow rise to a plateau by day 28. No further increase was seen by day 56. This sequence of early changes in fibronectin levels mirrored closely the time course of respiratory distress syndrome. Infants of mothers with pre-eclampsia had significantly lower peak fibronectin levels than in those without (P = 0.016), and those infants with bronchopulmonary dysplasia showed a trend towards lower basal fibronectin levels (P = 0.07) and a greater difference between peak and basal levels (P = 0.05). Neonates, particularly those born preterm, have blunted immunological responses to infection. Fibronectin plays a key role in immunological responsiveness. The significant changes in fibronectin levels after birth in the preterm neonate are likely to have important pathophysiological consequences.(ABSTRACT TRUNCATED AT 250 WORDS)

Fibronectin and the critically ill patient: current status

In summary, deficiency of plasma fibronectin has now been documented in a variety of clinical entities. Persistently low fibronectin may have prognostic value, and in certain patients may provide a clue to occult sepsis and potential organ failure. The clinical benefit of infusion of fibronectin-rich cryoprecipitate or purified human plasma fibronectin has yet to be determined in well-controlled randomized clinical trials. However, if such results become available then infusion of plasma fibronectin may provide a valuable therapeutic modality in the care of the critically-ill patient.

Retinol binding protein and prealbumin in Reye's syndrome

Retinol binding protein (RBP) and prealbumin (PA) were analyzed in 29 serum samples from 8 patients with stages II and III Reye's Syndrome (RS), and from 10 healthy fasting children. All RS patients had at least one abnormally low RBP and PA value. A return toward normal was evident within 2-3 days in serial samples. The nadir RBP and PA values in RS (means of 9 and 107 mg/L) were significantly different (p less than 0.001) from those of the controls (RBP mean of 40 and PA of 157 mg/L). A significant correlation was found between RBP and PA serum values in RS (r = 0.7, p less than 0.001); the high admission NH4+ values tended to associate with low RBP levels; however, the correlation was not very high (r = -0.4, p less than 0.01). The presence of an abnormal vitamin A transport system at an early stage of RS raises the possibility of additional abnormalities in vitamin A metabolism in these patients. The findings of reduced serum levels of complement, clotting factors, fibronectin, and now RBP and PA, suggest a marked short-term impairment of hepatic synthesis of proteins and/or their release in RS.