Although in this study the CD28 and CD38 expression levels did not change in patients suffering from an acute CMV infection,
other data report an expression of this same CD28 and MG-132 mw CD38 expression during CMV infection, limiting its clinical use. Soluble IL-2R (sIL-2R) levels in serum are increased as early as 10 days before the diagnosis of ACR but also increase in cases of CMV infection,[18, 19] bacterial infections and cholangitis.[20, 21] However, if the ratio of the post-transplant level divided by the pre-transplant level of SIL-2R was measured in combination with the levels of CD8, a more pronounced elevation of both levels was observed during CMV infection in comparison with ACR, where levels of CD8 are not increased. Soluble tumor necrosis factor (TNF) receptor II (sTNF-RII), released upon stimulation of T-helper (Th)1 lymphocytes, and IL-10, a counter regulatory Th2 cytokine, increase as well during ACR as during serious infections. Neopterin, an intermediate of tetrahydrobiopterin synthesis produced by interferon (IFN)-γ-activated macrophages, increased at the onset of ACR only in steroid-resistant patients. The pro-inflammatory cytokines IFN-γ, IL-1β, IL-4 and IL-6 were not of any use. IL-6 is an inducer of the hepatic synthesis of a myriad of acute phase proteins. Kita et al. observed in contrast a marked
rise of IL-6 during ACR and during infection, however, the rise pattern was distinguishable between both. Interleukin-15 is produced by non-lymphatic cells including macrophages, dendritic selleck cells and epithelial cells. Its www.selleckchem.com/products/CP-673451.html biologic activities are similar to those of IL-2. Plasma levels of IL-15 are increased during ACR, particularly during steroid-resistant ACR and during chronic rejection. Also, TNF-α, currently used on a daily basis in clinical settings as a marker of infection, once was proposed as a potential biomarker for ACR. Levels of TNF-α are elevated during ACR but cannot discriminate ACR from infection. β2-Microglobulin is a low molecular weight protein included in the major histocompatibility
complex class I complex required for its expression. ACR in cardiac and renal transplant patients is associated with increased levels of β2-microglobulin. The same was observed in liver transplantation, but this marker could not differentiate ACR from infectious complications.[26-28] The infiltration of leukocytes into the allograft during ACR is regulated by the expression of adhesion molecules. An increase of intercellular adhesion molecule 1 (ICAM-1) and E-selectin in serum was observed in relation to ACR. However, neither E-selectin[30, 31] nor ICAM-1 could differentiate ACR from an infectious episode. A differentiation was seen between patients with ACR and CMV infection, where ICAM-1 levels did not increase.