Beta-trace Protein Levels Research Articles

Effect of Clinical Variables and Immunosuppression on Serum Cystatin C and Beta-Trace Protein in Kidney Transplant Recipients

Cystatin C and beta-trace protein (BTP) are low-molecular-weight proteins that have generated interest as alternative endogenous markers of glomerular filtration rate (GFR). Studies examining the effect of demographic, biometric, clinical, and biochemical variables on cystatin C levels have yielded conflicting results, perhaps because of the reliance on inferior methods of GFR determination. The aim of this study is to examine the independent effect of various clinical parameters on serum concentrations of creatinine, cystatin C, and BTP in kidney transplant recipients. Cross-sectional study. 207 kidney transplant recipients with stable kidney function. GFR, age, race, sex, body mass index, albumin level, proteinuria, smoking status, prednisone, and calcineurin inhibitor and mycophenolate mofetil use. Multiple linear regression analysis was used to examine the relationship between predictor variables and cystatin C, BTP, and creatinine levels. GFR was measured by using technetium 99m-radiolabeled diethylenetriaminepentaacetic acid clearance. After adjusting for GFR, cystatin C and BTP levels were significantly lower in women compared with men. Greater albumin concentration was associated with significantly lower cystatin C and BTP concentrations. There was a statistically significant, but clinically small, association between body mass index and cystatin C level, but no association between the other demographic variables or medications analyzed. Predominantly white population; results may not be applicable to other racial groups. Important nonrenal factors can influence BTP and cystatin C concentrations and need to be considered when interpreting BTP and cystatin C values in kidney transplant patients.

Serum levels of beta-trace protein and its association to diuresis in haemodialysis patients

Beta-trace protein (BTP) has been proposed as an alternative endogenous marker of the glomerular filtration rate. However, possible determinants of BTP in ESRD patients undergoing regular renal replacement therapy have not been evaluated. Serum levels of BTP, beta-2-microglobulin, creatinine and urea were analysed before and after dialysis treatment in 73 patients [haemodialysis (HD) n=52; haemodiafiltration (HDF) n=21]. Patients were categorized into four groups with residual diuresis (RD)<0.5 l/day (group 1; n=24), 0.5-1 l/day (group 2; n=18), 1.1-1.5 l/day (group 3; n=12) and >1.5 l/day (group 4; n=19). Subsequently RD was compared to pre-treatment levels of BTP. HD treatment did not affect BTP serum levels [pre-treatment 8.1+/-4.1 mg/l (mean+SD) vs post-treatment 7.7+/-4.1 mg/l; -0.6 +/- 16.1%; ns]. However, in 6 out of 21 patients undergoing HDF BTP levels were reduced by more than 20%. Overall, the resulting decrease in serum concentration was minuscule (9.6+/-6.2 vs 8.3+/-4.9 mg/l; -14+/-21.9%; P=0.03). BTP serum levels were tightly associated to RD of the four groups. Comparison of BTP levels showed significant differences between patients of groups 1 vs 3 and 4 as well as 2 vs 4. BTP serum levels may serve as a surrogate marker for residual renal function since HD and HDF do not exert clinical relevant alterations on them. Furthermore, BTP serum concentrations appear strongly associated to RD.

Cystatin C, β‐2‐microglobulin and β‐trace protein in pre‐eclampsia

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 pre-eclampsia, 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. 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. 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 beta-trace protein displaying the best diagnostic performance of all the analytes. In this study, the maternal plasma levels of beta2-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.

Transpterygoid Trans-sphenoid Approach to the Lateral Extension of the Sphenoid Sinus to Repair a Spontaneous CSF Leak

Cerebrospinal fluid (CSF) fistula from the middle cranial fossa into the sphenoid sinus is a rare condition. In the past, the treatment of choice has been closure via a craniotomy. Only few geriatric cases are known, which were successfully operated by endoscopic surgery. We present a further case of nontraumatic CSF fistula originating from the middle cranial fossa. A new endoscopic technique was applied. We discuss treatment options for this rare defect. A 76-year-old patient presented with a 2-year history of rhinorrhea. High levels of beta-trace protein pointed to a diagnosis of CSF fistula. The defect was located at the anterior and inferior aspect of the pterygoid recess of the left sphenoid sinus. The patient was operated using an endoscopic trans-sphenoidal approach. After endoscopic opening of the maxillary and sphenoid sinus, a complete posterior ethmoidectomy was performed. The medial part of the pterygoid process was removed, allowing endoscopic exposure and closure of the defect. At 1-year follow-up, the CSF fistula had not recurred and the patient had no sequel from the surgical procedure. In selected cases, this new endoscopic partial transpterygoid approach to the middle cranial fossa is recommended for surgical repair of CSF fistula involving the lateral extension of the sphenoid sinus. To our knowledge, ours is the oldest patient with this condition successfully operated by endoscopic means at the world's most northern university hospital.

Beta-trace protein, a new marker of GFR, may predict the early prognostic stages of patients with type 2 diabetic nephropathy.

The relationship between serum levels of beta-trace protein (BTP) or serum creatinine (s-Cr) and the prognostic stages of type 2 diabetic nephropathy was determined. Serum samples from 174 patients with type 2 diabetes were obtained from Juntendo University Hospital, Tokyo, and Juntendo Urayasu Hospital, Chiba, Japan. They were classified into four groups according to the Report of the Ministry of Health and Welfare of Japan (1991, p 251-256) as follows: Stage I (normoalbuminuric stage), Stage II (microalbuminuric stage), Stage IIIA (macroalbuminuric stage without renal dysfunction), Stage IIIB (macroalbuminuric stage with renal dysfunction), and Stage IV (renal failure stage). Among these patients, 68 were Stage I, 29 Stage II, 32 Stage IIIA, 17 Stage IIIB, and 28 Stage IV. Levels of serum BTP were measured using the nephelometric assay on a BNA II analyzer (Dade Behring Diagnostics, Marburg, Germany). The mean levels of serum BTP in Stage IIIA were significantly higher than those in Stage I or II (P < 0.00001, P < 0.002, respectively). However, the mean levels of s-Cr in Stage IIIA were not significantly higher than that in Stage I or II. In conclusion, serum BTP was a good marker for the identification of early renal impairment in type 2 diabetes.

Serum levels of beta-trace protein and glomerular filtration rate—preliminary results

The aim of this study was to evaluate the relationship between serum levels of beta-trace protein (BTP), a low molecular weight (MW) protein, and glomerular filtration rate (GFR). GFR and serum levels of BTP, and for comparison creatinine (Creat), cystatin C (Cys) and β2-microglobulin (β2M), were measured in 60 patients, with renal function ranging from normality to advanced renal failure. Serum levels of BTP progressively increased with the reduction of GFR. A good correlation was found between GFR and serum levels of BTP ( r=0.918), Creat ( r=0.932), Cys ( r=0.937), and β2M ( r=0.924). Furthermore, no statistically significant difference was found between BTP and Creat, Cys, β2M, as indicators of a moderate GFR impairment. These preliminary data indicate that BTP might be suitable as an indicator of GFR.

Proteína beta traza en líquido cefalorraquídeo y suero en meningoencefalitis

beta-trace protein or D2 prostaglandin synthase is a dual functional protein. Its role and clinical value in cerebrospinal fluid is under study. Seventy four pediatric patients suffering from viral meningoencephalitis and 7 with bacterial meningoencephalitis were studied. Sera and cerebrospinal fluid samples were taken. Albumin and beta-trace protein were quantified by immunodiffusion and nephelometry respectively. Increased cerebrospinal fluid beta-trace protein levels in comparison with normal value were observed. Nevertheless such expected increment was no possible seen in bacterial meningoencephalitis. beta-trace protein may contribute with the etiological diagnosis in meningoencephalitis.

Levels of beta-trace protein and lysozyme in human amniotic fluids.

The levels of beta-trace protein and lysozyme were estimated in amniotic fluids from normal fetuses and from fetuses with neuraltube defects. The values of these proteins in normal amniotic fluids were found to be similar to those detected in fetuses with anencephaly and spina bifida. The levels of lysozyme were shown to be correlated with gestational age.