[Show abstract][Hide abstract] ABSTRACT: Introduction:
Some studies in hematology therapy suggest that blood concentration of transferring soluble receptor (sTfR) should be monitored to maximize efficacy control to reposition of iron. The transferrin receptor is an essential component of cellular uptake of iron, and it binds to serum transferrin. Recently, 2 different types of transferrin receptors have been recognized: transferrin receptor (TfR or transferrin receptor 1) and transferrin receptor 2. Most cells possess an ubiquitous system controlling the biosynthesis of TfR at the posttranscriptional level to avoid excess iron influx into the cells through TfR. During the process of recycling of transferrin receptors, some are shed and appear as soluble or serum transferrin receptors. Measurement of serum transferrin receptor is a new marker of iron metabolism that reflects body iron storage and total erythropoiesis. It has been shown that serum transferrin receptor and ferritin ratio has significant predictive value for differentiating iron deficiency anemia from non-iron deficiency anemia, such as anemia of chronic disorders.
[Show abstract][Hide abstract] ABSTRACT: There is little information regarding the 12-h mycophenolic acid (MPA) pharmacokinetics (PK), a way to monitor the drug and the need of frequent monitoring, in stable patients.
A cohort of 35 adults, under long-term mycophenolate mofetil (MMF) therapy plus cyclosporin A (n = 12), TACimus (n = 12) or MMF only (n = 11); all with prednisone had a 12-h MPA-PK performed to ascertain the percentage of them within a defined therapeutic window. In 13 other patients, two PK studies undergone 1 wk apart were performed to evaluate the need for frequent measurements.
Fourteen (40%) patients were within the defined therapeutic window (36-60 microg h/mL). Nine patients (26%) were overexposed while 12 (34%) were underexposed. A Cmax> or =10 microg/mL was seen in 20 (57%) of the patients. These percentages were equally distributed between the treatment groups both for AUC0-12 and Cmax. The equations using C0, C2 or both predict exposure, although the use of C2 seems to be more adequate in clinical practice. There were no differences in MPA exposure in patients with a repeated PK evaluated 1 wk later.
The use of MMF without monitoring MPA blood levels may cause over-/underexposure to the drug in stable recipients. However, in patients under MMF for more than 1 yr, MPA levels are stable and there is no need for frequent measurements.