Temporal changes of the plasma levels of cystatin C, beta-trace protein, beta(2)-microglobulin, urate and creatinine during pregnancy indicate continuous alterations in the renal filtration process

Objective. To determine the plasma levels of the renal functional markers creatinine, urate, cystatin C, beta(2)-microglobulin and beta-trace protein in samples from the first, second, early third and late third trimesters of 398 healthy women with uncomplicated singleton pregnancies. Material and methods. Plasma samples from 58 healthy non-pregnant women served as controls. The creatinine levels were significantly lower at all time-points in pregnancy, whereas the urate levels were lower during the first and second trimesters but increased in the late third trimester. The cystatin C, beta(2)-microglobulin and beta-trace protein levels displayed similar changes with increased levels in the third trimester but unaltered levels during the first and second trimesters. Results. The results indicate an increased filtration of low-molecular weight molecules during pregnancy, particularly during the first and second trimesters, whereas filtration of 10-30 kDa molecules is decreased in the third but unaltered in the first and second trimesters. The levels of albumin and alpha(2)-macroglobulin were measured in the same samples. Conclusions. The albumin levels decreased in the second and third trimesters, whereas the levels of alpha(2)-macroglobulin were unchanged, which is compatible with a virtually unaltered transfer of alpha(2)-macroglobulin between the intra-and extravascular space during pregnancy and a significantly increased extravascular fraction of albumin

Cystatin C, beta-2-microglobulin and beta-trace protein in pre-eclampsia

Background. An altered renal function is an essential component of the patho-physiology of pre-eclampsia. The plasma levels of low molecular mass proteins, e. g. beta-trace protein, beta-2-microglobulin and cystatin C, are increased in the third trimester of normal pregnancy. The plasma levels of cystatin C and beta-2-microglobulin are further increased in preeclampsia, and the cystatin C level has been reported to be a reliable marker for the disease. The aim of this investigation was to study the plasma levels of beta-trace protein, beta-2-microglobulin and cystatin C in pre-eclampsia, and to determine the diagnostic performance of these proteins compared to that of urate and creatinine. Methods. A case-control study of 57 women diagnosed with pre-eclampsia, and 218 healthy women with uncomplicated singleton pregnancies in the third trimester. Women in the catchment area of Lund, Sweden, were included during an 18-month period from October 2003 to April 2005. Venous blood samples were drawn upon inclusion when diagnosis was made. The maternal plasma concentrations of the 3 proteins were analysed by automated particle-enhanced immunoturbidimetric assays. Results. The plasma levels of the 3 proteins were significantly higher in the third trimester of pre-eclamptic patients compared to healthy pregnant women in the third trimester. The upper reference limits ( parametric 97.5 percentile) were 2.57 mg/l for beta-2-microglobulin, 0.72 mg/l for beta-trace protein and 1.37 mg/l for cystatin C. ROC analysis showed similar diagnostic performance for the 3 proteins, with b-trace protein displaying the best diagnostic performance of all the analytes. Conclusions. In this study, the maternal plasma levels of beta 2-microglobulin, beta-trace protein and cystatin C were all significantly elevated in pre-eclampsia compared to those of healthy pregnant women, and displayed similar diagnostic performance for diagnosing pre-eclampsia. The results indicate that low molecular mass proteins are useful as markers of renal impairment in pre-eclampsia

Thrombolytic therapy for eligible elderly patients with actite myocardial infarction - Reply

Dante Pazzanese Inst Cardiol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Cardiol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Cardiol, São Paulo, BrazilWeb of Scienc

Certification of proteins in the human serum Certified Reference Material ERM®- DA470k/IFCC

The production and certification of ERM-DA470k/IFCC, a new serum protein reference material intended to replace ERM-DA470, is described. Serum was produced from blood collected in 6 blood collection centres according to a procedure ensuring that it was obtained from healthy donors, and that the lipid content of the serum was low. The serum was processed in 5 batches, and then pooled, spiked with B2M and CRP and filled into vials (1 mL serum per vial). The serum was lyophilised in the vials and afterwards closed with rubber stoppers and screw caps and stored at -70 °C. The stability and homogeneity of the material were assessed for 14 proteins, including CER and B2M. ERM-DA470k/IFCC was characterised for 12 proteins using the reference material ERM-DA470 as calibrant. This was achieved using a value transfer protocol that can be considered as reference procedure. The techniques used to measure the protein concentrations were immunonephelometry, immunoturbidimetry, and for ALB also visible spectrometry. The measurements were performed with different platform/reagent combinations (Abbott Architect, Beckman Immage, BN II and BN ProSpec, different Hitachi instruments, Roche Integra, LX 2200, and Olympus AU640). In total 18 laboratories participated in the value assignment, 4 using open value transfer procedures, 12 using closed value transfer procedures, and 2 using both open and closed procedures. The results show that open and closed value transfer procedures give very similar results, and lead to robust values for A2M, AAG, AAT, ALB, C3c, C4, HPT, IgA, IgG, IgM, TRF, and TTR