ACE gene polymorphism and proliferative retinopathy in type 1 diabetes: results of a case-control study

OBJECTIVE

To evaluate the relationship between the ACE insertion/deletion polymorphism and proliferative diabetic retinopathy in patients with type 1 diabetes of long duration. Based on epidemiological and pathophysiological findings, risk factors apart from glycemic control and duration of disease are likely to be involved in the development of proliferative retinopathy.

RESEARCH DESIGN AND METHODS

In this case-control study, we compared 81 patients with longstanding (> or =20 years) type 1 diabetes who had nonproliferative (mild or moderate background) retinopathy with 95 patients with diabetes of similar duration and HbA1c who had proliferative retinopathy. To avoid the confounding effect of nephropathy, patients with overt nephropathy were excluded, and microalbuminuria was introduced into the multiple logistical regression model. The polymorphic region in intron 16 of the ACE gene (17q23) was analyzed using the polymerase chain reaction.

RESULTS

The ACE genotype distribution in patients with proliferative retinopathy (DD 39.4%, ID 48.9%, II 11.7%) was significantly different (P < 0.001) from that of patients with nonproliferative retinopathy (DD 17.3%, ID 54.3%, II 28.4%). In a multiple logistical regression analysis, the adjusted relative risk for proliferative retinopathy in a patient with a DD genotype compared with a patient with an II genotype was 6.6 (95% CI 2.2-19.5), P = 0.0026. In addition to genotype, systolic blood pressure (odds ratio 1.027 [95% CI 1.0-1.1], P = 0.0093) but not microalbuminuria (< or =20 vs. > or =20 microg/min) reached statistical significance in the multiple regression model. Because subjects were matched regarding diabetes duration and HbA1c, we did not interpret the respective parameter estimates.

CONCLUSIONS

These data provide evidence that deletion in the ACE gene is associated with the prevalence of proliferative retinopathy in type 1 diabetes and suggest that the DD genotype confers susceptibility to proliferative retinopathy independent of diabetic nephropathy

Apoptosis of tubular epithelial cells in donor kidney biopsies predicts early renal allograft function

Acute renal failure (ARF) is a serious complication in the early postoperative period after kidney transplantation. In an effort to identify subjects at risk, several donor-, recipient-, and procedure-related factors have been studied. Because no morphologic parameter predictive of delayed graft function has been identified to date, this study was conducted to determine whether the number of apoptotic cells in donor biopsies obtained before engraftment is predictive of the development of posttransplant ARF. Donor biopsies of patients with "biopsy-proven" acute tubular damage but no signs of rejection (n = 23) showed significantly higher counts of apoptotic tubular epithelial cells when compared to patients with immediate transplant function (n = 44) or early rejection (n = 22). In all groups, a significantly higher percentage of apoptotic cells was found in the distal compared to the proximal tubule. The expression of bcl-2 and proliferating cell nuclear antigen was not different among the groups. Late allograft function was not affected by early ARF as serum creatinine values were similar in all three groups after 6 mo. These data suggest that the number of apoptotic renal tubular epithelial cells in donor biopsies before engraftment is predictive of the early postoperative course in patients undergoing kidney transplantation.

[Potentials risks in drug prevention of thrombosis--low-molecular-weight heparin versus standard heparin]

INTRODUCTION

At present, low molecular-weight heparins are recommended for efficient prophylaxis of thrombembolic complications (TEC), especially in the high-risk areas of orthopedics and trauma surgery. In addition to improved efficacy, a markedly reduced risk of side-effects should also be of great advantage, particularly in terms of heparin-induced thrombocytopenia (HIT) type II, a medicative side-effect which can be associated with severe to life-threatening complications.

METHODS

In a prospective study, the incidence of heparin-induced thrombocytopenia HIT type II and the incidence of symptomatic TEC in high-risk orthopedic patients was investigated when the low molecular-weight heparin, enoxaparin, was applied. An analogous study using standard heparin (UFH) served as the comparison group. When the thrombocyte count dropped by 50% compared to the initial value, or when thrombembolic complications with clinical symptoms arose, the serum was examined in the heparin-induced platelet activation test (HIPA test). Phlebography was used to verify symptomatic TEC.

RESULTS

325 patients who had undergone surgery for total hip or knee arthroplasty or for the revision of hip and knee total endoprostheses took part in the study. 3 patients (0.92%) developed clinically symptomatic complications. No HIT type II was observed in the study population. The comparison group (UFH) consisted of 307 patients who had undergone analogous surgery. 13 patients (4.2%) developed clinically symptomatic TEC. In 10 patients (3.3%), these were associated with HIT type II The difference in the thrombosis rate and incidence of HIT type II between the two groups is highly significant.

CONCLUSION

For the prophylaxis of thrombembolic complications--especially in the high-risk areas of orthopedics and trauma surgery--unfractioned standard heparin (UFH) is insufficiently effective and associated with a high risk of side-effects, particularly of HIT type II. Low molecular-weight heparins must thus be considered the preferred medication in thrombembolism prophylaxis.

Aptamers as tools in molecular biology and immunology

We have listed and described recent promising developments in the field of aptamer research. The properties and the application potential of aptamers propose an exciting future for aptamers either in the clinic or as research tools for various purposes. We have reviewed exciting examples in which the SELEX technology was applied to obtain promising tools that may help to facilitate our understanding of biological processes and to interfere at distinct points in signal transduction cascades. High affinities and specificities of aptamer/target-interactions can now routinely be achieved. Furthermore, a wide spectrum of chemical modifications of nucleotides is known which greatly increase the stability of RNA molecules in biological materials, considerably enhancing their application potential. The aptamer technology shows that the combination of organic synthesis and molecular biology can contribute to interesting and promising new drug leads, which may very soon find their way into daily clinical practice or onto the laboratory benches of many researchers in the life sciences.

Application of the green fluorescent protein as a reporter for Ace1-based, two-hybrid studies

The two-hybrid system in Saccharomyces cerevisiae is a genetic approach for the detection of of protein-protein interactions in vivo. This technology relies on the the activity of separated DNA-binding and transactivation domains of specific transcription factors to reconstitute an active transcription factor complex if interacting proteins are fused to these domains. Interactions are consequently detected through the activity of reporter genes. The two-hybrid technology has been successfully applied for the determination of interactions between numerous proteins of several organisms. Conventional reporter systems, such as the beta-galacatosidase from Escherichia coli, suffer from a variety of drawbacks, including the requirement for external substrates. In this report, we describe an alternative version of the two hybrid system using the combined advantages of the copper-inducible transcription factor Acel together with the yeast metallothionein gene CUP1 and the green fluorescence protein from aquatic invertebrates as reporters. This technique allows the copper-dependent monitoring of protein-protein interactions in living yeast cells.

Immunomodulating and antimetastatic activity of thymic peptides in BALB/c mice

The immunomodulating and antimetastatic activity of a clinically approved low molecular weight, standardized thymic peptide (TP) preparation was evaluated in BALB/c-mice. Daily subcutaneous application of TP (7 consecutive days, 1 and 10 micrograms per mouse) upregulated counts and activity of peripheral blood cells, as measured on day 14. To check the influence of TP on experimental liver metastases (liver colonization), RAW H10 lymphosarcoma cells were intravenously inoculated into BALB/c-mice. TP (1,10,100 micrograms/mouse) was subcutaneously administered daily for 7 consecutive days starting 24 hrs after tumor cell challenge. Liver colonization was investigated on day 14 after tumor cell inoculation and demonstrated a statistically significant (p < 0.05) reduction of experimental liver metastases for TP treated mice.

Enhancing of anti-viral activity against HIV-1 by stimulation of CD8+ T cells with thymic peptides

HIV-1 can be neutralized by soluble factors produced and secreted by activated CD8+ T cells. Production of such anti-viral CD8 factors (including chemokines) can be induced with IL-2 or phytohaemagglutinin (PHA). In addition to PHA or IL-2, we have co-stimulated CD8+ T cells with PHA/IL-2 and a mixture of thymic peptides (TP) of molecular weights below 10 kD. For the activation, CD8+ T cells were purified from peripheral blood mononuclear cells of HIV-1- individuals and any resultant anti-viral activity was monitored using an HIV-1 neutralization assay. Using HIV-1 isolates highly resistant to chemokine inhibition we detected significantly higher levels of HIV-1 neutralizing activity in CD8+ T cell culture supernatants which had been co-activated with TP. When the TP-induced anti-viral activity was monitored, neutralization of both non-syncytia-inducing (NSI) and syncytia-inducing (SI) patient isolates was enhanced by 38% (NSI, PHA +/- TP), 66% (SI, PHA +/- TP), 28% (NSI, IL-2 +/- TP), and 57% (SI, IL-2 +/- TP) compared with the anti-viral activity present in supernatants from CD8+ T cell cultures stimulated only with PHA or IL-2. Peptide sequence analysis of purified TP showed that the TP mixture predominantly contains peptides with homology to human histone and collagen sequences. Our data demonstrate that CD8+ T cells are additionally activated by a mixture of TP. In this way, the production of HIV-1 neutralizing CD8 factors can be enhanced.

Lipid-lowering therapy in membranous nephropathy

Membranous nephropathy (MN) is a very common cause of nephrotic syndrome in adults, and lipid abnormalities are, therefore, frequently found in these subjects. Although efficient lipid-lowering therapy is available, almost nothing is known about the contribution of hyperlipidemia in the pathogenesis of progressive renal failure in MN. Studies in an experimental animal model of human MN, Heymann nephritis, have shown that lipids play an essential role in the pathogenesis of proteinuria. Local production of reactive oxygen species after subepithelial immune complex deposition leads to the formation of lipid peroxidation (LPO) adducts, which ultimately alter the composition of the glomerular basement membrane. As the magnitude of urinary protein excretion is associated with the long-term prognosis, a normalization of glomerular permselective properties has been used as a surrogate parameter for the beneficial effects of treatment. Probucol, a drug with LPO inhibitor potential, is able to reduce urinary protein excretion in rats with passive Heymann nephritis. In humans with MN, preliminary data also support this observation. It remains to be determined, however, if this intervention, which does not interfere with immune complex formation, will reduce the number of the patients reaching end-stage renal failure because of MN. In conclusion, lipids may contribute to glomerular injury in MN, as LPO might be an especially important factor, opening the possibility for new therapeutic interventions, thereby avoiding the side-effects of the currently used treatment regimen.

Dual reporter systems in yeast and mammalian cells for assessing progesterone receptor modulators

In the present study we describe the set-up of a new one-hybrid reporter gene assay in Saccharomyces cerevisiae composed of the human progesterone receptor fused to the DNA-binding domain of the yeast transcriptional activator Gal4. This assay allows the convenient estimation of receptor mediated progestogenic as well as antiprogestogenic actions of compounds. The induction of the beta-galactosidase reporter gene expression correlated well with the progesterone receptor affinity and the concentration of the progestins tested. The results corresponded to those obtained from a reporter gene assay in the cancer cell line CV-1 and in vitro binding experiments using rabbit uterus cytosol. In both the yeast and CV-1 cells the activity of antiprogestins was detectable by inhibition of the progestin-induced reporter gene expression. Secondary reporter genes under the transcriptional control of receptor unrelated promoters have been introduced into yeast and mammalian test strains to distinguish between specific receptor mediated antihormone actions and nonspecific effects on cellular metabolism.

Effect of high-dose melphalan and peripheral blood stem cell transplantation on renal function in patients with multiple myeloma and renal insufficiency: a case report and review of the literature

Multiple myeloma with IgG-lambda monoclonal gammopathy and severe renal impairment with light-chain deposit disease was diagnosed in a 51-year-old man. Following conventional therapy with VAD (vincristine, adriamycin, dexamethasone) a partial remission was achieved. Peripheral blood stem cells (PBSC) were then collected following mobilization with cyclophosphamide and recombinant human granulocyte colony-stimulating factor and enriched for CD34-positive cells by immunoaffinity column. Fourteen months after diagnosis high-dose melphalan was given, followed by infusion of CD34-positive PBSC. Aside from mild oral mucositis and trigonitis, high-dose therapy was tolerated well. After he underwent PBSC transplantation his renal function improved, and the patient has been in in continuous complete remission for 1 year. Thus, high-dose chemotherapy can be safely administered to patients with multiple myeloma and severe renal impairment. Our findings confirm previous reports summarized in the current presentation.

Immunogold signal amplification: Application of the CARD approach to electron microscopy

Catalyzed reporter deposition (CARD) is a technique that allows amplification of routine immunolabeling in light microscopy. This procedure takes advantage of the horseradish peroxidase (HRP) from an HRP-avidin complex to catalyze the accumulation of reporter-conjugated tyramine (a phenolic compound) onto a surface displaying biotinylated antigen-antibody complexes. The large amount of labeled tyramine deposited allows the detection of an antigenic site with multiple reporter molecules. In this study we modified this amplification protocol to combine it with the immunogold technique for the ultrastructural localization of antigens in electron microscopy. We constructed various tyramide conjugates that permit the combination of this amplification method with a particulate colloidal gold marker. The new probes yield results of high specificity and enhanced intensity. Assessment of the level of resolution of the labeling has demonstrated that, in spite of the amplification, the resolution remains very good. Therefore, once associated, the immunogold and the CARD techniques lead to specific, high-resolution, sensitive and amplified signals that exhibit the advantages of both approaches.(J Histochem Cytochem 47:421-429, 1999)

Anemia and carnitine supplementation in hemodialyzed patients

Carnitine supplementation in hemodialyzed patients was studied in a double-blinded, randomized, controlled trial in order to elucidate the effect of intravenous carnitine on renal anemia in patients treated with recombinant human erythropoietin (rHuEPO). Twenty stable hemodialysis (HD) patients received intravenous L-carnitine after each dialysis session in a dosage of 5 (N = 15) and 25 (N = 5) mg/kg, respectively, together with intravenous iron saccharate (20 mg/HD session) for four months and without iron for a further four months. Twenty patients received placebo instead of carnitine with an identical iron regimen. After a run-in phase of six months with a stable rHuEPO requirement, the rHuEPO dose was adjusted monthly when necessary to maintain target hemoglobin levels. At study entry (T0), plasma and red blood cell carnitine levels did not correlate significantly with the rHuEPO requirement. However, plasma free and total carnitine levels showed a significant negative correlation with erythrocyte survival time at T0. After four months of coadministration of intravenous iron and L-carnitine (T4), the rHuEPO requirement decreased in 8 of 19 evaluable HD patients. In these responders, the weekly rHuEPO dose was decreased significantly by 36.9+/-23.3% (183.7+/-131.7 at T0 vs. 126.6+/-127.9 U/kg/week at T4, P < 0.001). The rHuEPO requirement, however, was unchanged when all carnitine-treated patients were compared between T0 and T4 (T0: 172.0+/-118.0 vs. T4: 152.3+/-118.8 U/kg/week, P = 0.07, NS), but the erythropoietin resistance index decreased significantly in this group (T0: 16.0+/-11.0 vs. T4: 13.6+/-10.5 U/kg/week/g of hemoglobin, P < 0.02). The erythrocyte survival time was measured in five HD patients treated with iron and carnitine at T0 and T4. Two out of these patients were carnitine responders and showed an increase of erythrocyte survival time of 15 and 20%, respectively. After the withdrawal of iron supplementation, the rHuEPO requirement increased comparably in both L-carnitine- and placebo-treated patients during four more months. According to our data, L-carnitine, in addition to iron supplementation, may have an effect on erythropoietin resistance and erythrocyte survival time in HD patients. More than half of our patients, however, showed no benefit. Further studies to identify those HD patients who might have a benefit of carnitine supplementation, as well as studies concerning the optimal dosage, duration, and way of administration of carnitine supplementation and its mechanism of action, are required.

Post-transplant acute myeloid leukemia (PT-AML)

Acute myeloid leukemia following organ transplantation (PT-AML) is a rare event with only a few published cases in the literature. We present three patients who developed AML (FAB M1, M5, M4) after renal, double lung or liver transplantation. Molecular analysis detected a t(9;11) in one patient and documented the recipient origin of AML in a second patient. All patients were treated with chemotherapy. Immunosuppression was reduced to cyclosporin A (CsA) and prednisone in two patients and to prednisone alone in one patient. Two patients achieved a complete remission (CR), with a remission duration of 4.6 months in one patient, the other patient died from septicemia after 15.2 months in CR. One patient was refractory to chemotherapy and died from septicemia. This report together with the documented cases in the literature suggests that PT-AML (1) develops after a median interval of 5 years after transplantation with variable latency (range, <1-17 years); (2) is heterogeneous with respect to FAB classification; (3) shows chromosomal and molecular changes typical of therapy-related AML (t-AML: -7, +8, 11q23, inv16, t(15;17)); (4) standard chemotherapy is feasible after reduction of immunosuppression and produces a CR rate of 56% with a median remission duration of 4.6 months and an overall survival of 2.6 months; (5) the major complications are early death (25%), gram-negative septicemia, progressive disease or relapse. This review provides diagnostic and therapeutic experiences and guidelines for the management of this increasing group of post-transplant patients.

Cloning of a second nm23-M1 cDNA: expression in the central nervous system of adult mouse and comparison with nm23-M2 mRNA distribution

Nm23 has been identified as a gene family encoding different isoforms of the nucleoside diphosphate kinase. This protein is a key enzyme in the control of cellular concentrations of nucleoside triphosphates. Moreover, it has been shown to play important roles in various cellular functions such as differentiation and metastasis. In the present study, a second cDNA for nucleoside diphosphate kinase A (Nm23-M1) was isolated from a cDNA library of mouse embryonic stem cells. This clone encodes the same putative 152 aminoacids long protein as an already published cDNA but is longer in both its 5' and 3' untranslated regions. Tissue and cellular distribution of nm23-M1 mRNA was investigated by using Northern blot analysis and in situ hybridization. Nm23-M1 transcripts were found to be widely distributed throughout the mouse central nervous system with prominent expression in several restricted areas. No differences were noticed between the distribution of long and short transcripts. Furthermore, a similar pattern of expression was described in the central nervous system for nm23-M2 mRNA, encoding a second isoform of the nucleoside diphosphate kinase. However, the transcript of this isoform displayed a wider distribution and was expressed in all organs analysed by northern blotting. The possible involvement of nm23-M1 in differentiation of mouse nervous system is further discussed.

Novel C5-dependent mechanism of neutrophil stimulation by bioincompatible dialyzer membranes

The objective of the study was to evaluate the contribution of reactive oxygen intermediate formation for receptor modulation on neutrophils by the cellulosic dialyzer membrane cuprophan (CU). In patients dialyzed with CU, CD11b and CD66b upregulation on neutrophils (by 104.3 +/- 37.9% and 85.7 +/- 31.1%, respectively), and a downregulation of L-selectin (by 44.9 +/- 26.9%) was seen, whereas expression of CD11a remained unaltered. Hemodialysis with polysulfone did not bring about major changes in surface receptor expression. In vitro incubation of isolated neutrophils in the presence of serum with hollow fibers of CU or polysulfone showed similar results: Only CU resulted in upregulation of CD11b and CD66b expression (by 65.5 +/- 18.7% and 60.1 +/- 24%) and a decrease in CD62L expression (by 60.6 +/- 18.2%). In contrast to receptor alterations, generation of reactive oxygen intermediate by CU occurred in the absence of serum. Inhibition experiments with soluble complement receptor 1, which produced only partial inhibition of receptor up-/down-regulation, indicated the existence of also other than alternate complement-dependent mechanisms for neutrophil activation. By using C5-depleted serum instead of normal human serum, up-/down-regulation of CD11b, CD62L, and CD66b by CU was dramatically reduced, whereas C3-depleted serum did not produce that effect. C5-deficient serum repleted with purified C5, as well as purified C5 alone, was able to induce receptor modulation by CU comparable to normal human serum. L-Methionine, a specific inhibitor for the oxidative activation of C5, blocked the modulatory effect of CU in assays with purified C5 as well as with serum. As a result, in addition to the alternative pathway of complement, a C5-dependent mechanism probably activated by neutrophil-derived reactive oxygen intermediate leads to receptor modulation and subsequent generation of the well known side effects of bioincompatible dialyzer membranes.

The StrQ protein encoded in the gene cluster for 5'-hydroxystreptomycin of Streptomyces glaucescens GLA.0 is a alpha-D-glucose-1-phosphate cytidylyltransferase (CDP-D-glucose synthase)

The gene strQ was identified as the last gene of a putative transcription unit, strB1FGHPQ, located in the gene cluster for the production of 5'-hydroxy-streptomycin (OH-Sm) in Streptomyces glaucescens GLA.0. [In contrast, the corresponding operon in the str/sts-gene cluster of the Sm-producer Streptomyces griseus, strB1FGHIK, differs in the two distal genes; Mansouri, K. & Piepersberg, W. (1991) Mol. Gen. Genet. 228, 459-469]. The deduced StrQ protein exhibited similarities to members of the enzyme family of hexose-1-phosphate nucleotidylyltransferases (NDP-hexose synthases or pyrophosphorylases), with the strongest similarity to the subfamily of alpha-D-glucose-1-phosphate cytidylyltransferases (CDP-D-glucose synthases). The StrQ protein was heterologously expressed in Escherichia coli. The purified protein revealed an enzyme activity of that of a CDP-D-glucose synthase and a substrate specificity restricted to CTP and alpha-D-glucose 1-phosphate. The K(m) and Vmax values determined for CTP are 44 microM and 920 microM and for alpha-D-glucose 1-phosphate 195 microM and 1.06 mM, respectively. The CDP-D-glucose synthase activity was also detected in cells of S. glaucescens under the conditions of antibiotic production, but was absent from cells of the streptomycin producer S. griseus N2-3-11. Also, the genomes of several strains of S. griseus did not seem to possess strQ-related genes. In contrast, hybridisation experiments indicated that genes homologous to strQ were probably present in various other actinomycetes producing aminoglycosides. A possible function of the StrQ protein in the OH-Sm biosynthetic pathway of GLA.0 is discussed.

Aprotinin counterbalances an increased risk of peri-operative hemorrhage in CABG patients pre-treated with Aspirin

OBJECTIVE

As Aspirin (ASA) has proven efficacy in preventing patients with CAD from complications related to cardiovascular diseases, most patients scheduled for CABG are treated with ASA therapy. Consequently, impaired hemostasis is a problem in the management of CABG patients. Clinical studies have shown that Aprotinin can reduce bleeding and the use of blood products by 50% in patients both with and without pre-operative ASA therapy. Concerning the combined effect of peri-operative low-dose ASA therapy and intra-operative high-dose Aprotinin therapy, the gathering of additional and prospective data seemed to be necessary.

METHODS

We conducted a double-blind two-centre randomised three-arm study in patients with elective primary CABG surgery. Three groups have been tested, comprising 119 patients in total (group A: ASA + Aprotinin, group B: placebo + Aprotinin, group C: placebo + placebo) to investigate a possible reduction of bleeding in Aprotinin treated patients. For all patients, thromboxane levels were used to identify ASA or placebo treatment.

RESULTS

The post-operative blood loss is significantly reduced by 21% after Trasylol administration (B vs. C; P = 0.009). The unexpected result of this study has been that the pre-treatment with ASA led to a further reduction of 18% (A vs. C; P < 0.0001). The difference between the two Aprotinin groups (A and B) is significant (P = 0. 01) in favour of ASA pre-treatment. Myocardial infarction (MI) had been diagnosed at levels of 1.8% in total (2/113), 2.6% (1/38) in group B and 3.2% (1/31 ) in group C. An additional blinded evaluation of ECG, enzyme levels and clinical status revealed 'definite, probable and possible' MIs of 5% in group A, compared to 16% in group B and 13% in group C, thus providing no evidence for a higher risk of infarction by Aprotinin treatment. When comparing the ASA group to non-ASA pre-treatment, a strong trend towards a reduction in MI rate becomes obvious, from 15% to 5% in favour of the ASA pre-treatment (P = 0.08). Concerning other peri-operative complications, no statistical difference between the groups could be detected.

CONCLUSIONS

A reduction in post-operative blood loss in primary elective CABG surgery with intra-operative Aprotinin treatment could be confirmed. A low-dose ASA treatment combined with a high-dose aprotinin administration during surgery not only neutralized a potentially higher risk of bleeding, but did in fact reduce the post-operative blood loss. The protective effect of ASA on peri-operative MI has been evident through a reduction of MI rate in ASA treated patients.

Plasma immunadsorption treatment in patients with primary focal and segmental glomerulosclerosis

BACKGROUND

In primary focal and segmental glomerulosclerosis (FSGS) renal prognosis is poor if no remission of proteinuria can be obtained by treatment. In some patients a permeability factor, responsible for damaging the glomerular epithelial cell and detectable by an in vitro test (GVV-test), seems to be present in the serum.

METHOD

We determined the effects of an immunadsorption treatment (IAT) on proteinuria and glomerular permselectivity (using a neutral dextran and dextransulfate-sieving technique to assess glomerular size and charge selectivity) in five patients with FSGS in the native kidneys and three patients with recurrence of FSGS after kidney transplantation. Furthermore, we performed the GVV-test using sera obtained from the patients before and after therapy.

RESULTS

IAT reduced proteinuria by more than 50% in four patients, all of whom had an improvement in glomerular-size selectivity. Charge selectivity was better preserved after therapy in three out of these four subjects. The GVV-test prior to IAT was positive in two patients who also responded clinically to therapy. After IAT the GVV-test was negative in all patients, indicating an elimination of the proteinuric factor in the two previously positive patients.

CONCLUSION

We conclude that a positive GVV-test before treatment makes a favourable response of IAT on proteinuria likely in patients with FSGS. If a reduction of proteinuria can be obtained by IAT this is due to an improvement in glomerular size and/or charge selectivity.