Bactericidal activity of ascitic fluid in patients with nephrotic syndrome

Spontaneous Bacterial Peritonitis in an Adult Patient with Minimal Change Disease

Patient: Male, 60-year-old

Final Diagnosis: Peritonitis

Symptoms: Abdominal pain • edema of lower extermities

Medication: —

Clinical Procedure: —

Specialty: Nephrology

Advances in biocompatibility and physico-chemical characterization of microspheres for cell encapsulation

Cell encapsulation has already shown its high potential and holds the promise for future cell therapies to enter the clinics as a large scale treatment option for various types of diseases. The advancement in cell biology towards this goal has to be complemented with functional biomaterials suitable for cell encapsulation. This cannot be achieved without understanding the close correlation between cell performance and properties of microspheres. The ongoing challenges in the field of cell encapsulation require a critical view on techniques and approaches currently utilized to characterize microspheres. This review deals with both principal subjects of microspheres characterization in the cell encapsulation field: physico-chemical characterization and biocompatibility. The up-to-day knowledge is summarized and discussed with the focus to identify missing knowledge and uncertainties, and to propose the mandatory next steps in characterization of microspheres for cell encapsulation. The primary conclusion of this review is that further success in development of microspheres for cell therapies cannot be accomplished without careful selection of characterization techniques, which are employed in conjunction with biological tests.

Alginate microbeads are complement compatible, in contrast to polycation containing microcapsules, as revealed in a human whole blood model

Alginate microbeads and microcapsules are presently under evaluation for future cell-based therapy. Defining their inflammatory properties with regard to humans is therefore essential. A lepirudine-based human whole blood model was used as an inflammation predictor by measuring complement and leukocyte stimulation. Alginate microbeads were complement-compatible since they did not activate complement as measured by the soluble terminal complement complex (sTCC), Bb or the anaphylatoxins C3a and C5a. In addition, alginate microbeads were free of surface adherent leukocytes. In contrast, microcapsules containing poly-L-lysine (PLL) induced elevated levels of sTCC, Bb, C3a and C5a, surface active C3 convertase and leukocyte adhesion. The soluble PLL induced elevated levels of sTCC and up-regulated leukocyte CD11b expression. PMCG microcapsules containing poly(methylene-co-guanidine) complexed with sodium alginate and cellulose sulfate triggered a fast sTCC response and C3 deposition. The PMCG microcapsules were still less activating than PLL-containing microcapsules as a function of time. The amounts of anaphylatoxins C3a and C5a were diminished by the PMCG microcapsules, whereas leukocyte adherence demonstrated surface activating properties. We propose the whole blood model as an important tool for measuring bioincompatibility of microcapsules and microbeads for future applications as well as determining the mechanisms leading to inflammatory reactions.

T cell CD3 receptor zeta (TCRzeta)-chain expression in children with idiopathic nephrotic syndrome

Children with idiopathic nephrotic syndrome (INS) have an increased risk of developing life-threatening infections. Several studies have demonstrated functional abnormalities in the T lymphocytes of patients with nephrotic syndrome. Although T cells are activated in INS during relapse, as indicated by an increased expression of interleukin (IL)-2 receptor, these cells have a decreased ability to proliferate. The T-cell receptor (TCR) plays an important role in signal transduction and T cell activation, with the TCR-zeta (TCRzeta) chain being a key element in early signaling. We measured the expression of the TCRzeta chain in patients with INS (steroid resistant and steroid sensitive) during relapse and remission by flow cytometry and by PCR ELISA. The results showed a significant decrease in the expression of the TCRzeta chain at both the protein and mRNA level in INS patients during relapse as compared with normal controls (p < 0.05). In contrast, when patients with INS achieved remission, the expression of TCRzeta normalized and was similar to that expressed in normal controls. Therefore, a decreased expression of the TCRzeta chain may explain the abnormal function of T cells in patients with INS, and it may also contribute to the increased risk for infections seen in these patients.

Ascites in Nephrotic syndrome. Incidence, patients' characteristics, and complications

The pathophysiology of ascites in patients with cirrhosis is complex and includes increases in hepatic sinusoidal pressure, the formation of hepatic and splanchnic lymph, renal sodium retention, and hypoalbuminemia. However, the role of hypoalbuminemia in ascites formation is controversial. Evaluating ascites in hypoalbuminemic patients with nephrotic syndrome could add to our understanding of the role of hypoalbuminemia in ascites development. We conducted a retrospective analysis of 52 adults and 21 children with nephrotic syndrome who were hospitalized in the Hadassah University Hospital on Mount Scopus during 1981-1994. There was a significant difference in the prevalence of ascites between pediatric (52%) and adult patients (23%) (p = 0.024). Pediatric patients had lower serum albumin levels than adults (1.70 +/- 0.08 g/dl vs. 2.10 +/- 0.07 g/dl, p = 0.001). Adult patients with ascites had lower serum albumin levels than adult patients without ascites (1.80 +/- 0.13 g/dl vs. 2.20 +/- 0.07 g/dl, p = 0.01). This difference was not found in pediatric patients. Temporary fluctuations in liver enzymes (up to four times the upper limit of normal for transaminases) were evident in five patients from the pediatric group with ascites, whereas all pediatric patients without ascites had completely normal liver enzymes (p = 0.035). Among the 12 adult patients with ascites, seven had liver disease (three with cirrhosis and four with amyloidosis), and two had right-sided congestive heart failure. Among the 40 adult patients without ascites, only four had liver disease (amyloidosis). The plasma albumin levels of the patients with amyloidosis without ascites were higher than patients with amyloidosis with ascites (1.90 +/- 0.10 g/dl vs. 1.50 +/- 0.07 g/dl, p = 0.03). Two patients with nephrotic syndrome and ascites (one without liver disease) had episodes of spontaneous bacterial peritonitis. Ascites in nephrotic syndrome is more common in children than in adults. Although in most pediatric patients ascites formation is probably a common manifestation of the general fluid retention, in most adult patients with nephrotic syndrome ascites can be attributed to both hypoalbuminemia and the presence of liver disease or congestive heart failure, with increased hepatic sinusoidal pressure.

Effect of transferrin concentration on bacterial growth in human ascitic fluid from cirrhotic and neoplastic patients

Cirrhotic patients with ascites have an unusually high frequency of development of spontaneous bacterial peritonitis. Iron availability is a key factor in bacterial growth and the ability of the host to limit it is associated with resistance to infection. The present study was undertaken to evaluate the influence of iron and transferrin on bacterial growth in ascitic fluid from 25 biopsy-proven cirrhotic and nine neoplastic carcinomatous patients. No significant differences were found when comparing total ascitic fluid iron between the two groups but ascitic fluid transferrin concentration was significantly lower in cirrhotic (29.26 mg dl-1 SD 29.58) than neoplastic (96.57 mg dl-1 SD 76.01) patients. Moreover, a significant negative correlation was found between bacterial growth and transferrin concentration in ascitic fluid (P = 0.039). When the iron concentration in ascitic fluid was experimentally elevated (50 micrograms dl-1 or 150 micrograms dl-1) we observed a progressive increase in bacterial growth. If transferrin concentration is simultaneously elevated (250 mg dl-1) this increase does not occur. These findings indicate that the transferrin level is an important factor in the regulation of bacterial growth in ascitic fluid and that the low concentration found in cirrhotic patients could facilitate spontaneous bacterial peritonitis.