Cluster approximation applied to multisite-occupancy adsorption: configurational entropy of the adsorbed phase for dimers and trimers on triangular lattices.

The adsorption of dimers and trimers on triangular lattices is studied by combining theoretical modeling and Monte Carlo (MC) simulations. The thermodynamic process is analyzed through the behavior of the configurational entropy per site of the adsorbed phase as a function of the coverage. MC calculations, supplemented by the thermodynamic integration method, are performed in the grand canonical ensemble. The theoretical model used in the present study is called Cluster Approximation (CA), and it is based on exact calculation of states on finite cells. An efficient algorithm allows us to determine the detailed structure of the configuration space for m = l1 × l2 cells. From there, the thermodynamic properties can be obtained. Five systems are investigated, according to the size and shape of the molecule in the adsorbed state: (i) dimers, (ii) linear trimers, (iii) triangular trimers, (iv) 60°-angular trimers and (v) 120°-angular trimers on triangular lattices. Dimer and trimer are the simplest cases of a polyatomic adsorbate, containing all the properties of the multisite-occupancy adsorption and can be used to model several experimental systems. CA solutions are tested by comparison with MC simulations and previous data in the literature. Special interest is devoted to the calculation of the configurational entropy per site in the limit case of θ → 1 (full coverage), where some exact results are available. The theoretical formalism is also applied to model CH4 and CO2 clathrate hydrates. In these systems, a triangular lattice is used to simulate the substrate, and methane(carbon dioxide) molecules can be well represented by triangular(linear) trimers. The good qualitative agreement between simulation and analytical data supports the validity of the CA scheme to predict the behavior of a wide variety of multisite-adsorption models, for which theoretical solutions are very difficult to obtain.

In vitro evaluation and in vivo efficacy of nitroimidazole-sulfanyl ethyl derivatives against Leishmania (V.) braziliensis and Leishmania (L.) mexicana.

The aim of this study was to synthesize several small molecules of the type 5-nitroimidazole-sulfanyl and evaluate biological properties against the main Leishmania species that cause cutaneous leishmaniasis in Venezuela. Final compounds 4-7 were generated through simple nucleophilic substitution of 1-(2-chloroethyl)-2-methyl-5-nitroimidazole 3 with 2-mercaptoethanol, 1-methyl-2-mercaptoethanol, and 2-thyolacetic acid derivative. Compound 8 was synthesized via a coupling reaction between 7 and (S)-Methyl 2-amino-4-methylpentanoate hydrochloride. The inhibitory concentrations of (3, 4, 7, 8) against Leishmania (L.) mexicana and (V.) braziliensis in promastigotes and experimentally infected macrophages were determined by in vitro activity assays. Compounds 7 and 8 shown high activity against both species of Leishmania and were selected for the in vivo evaluation. Animals were infected with promastigotes of the two species and divided into four groups of ten (10) animals and a control group. Intralesional injection way was used for the treatment. The parasitological diagnostic after treatment was obtained by PCR using species specific oligonucleotides. The two Leishmania species were susceptible to compounds 7 and 8 in vivo assays. The results indicated that both compounds reduce significantly (96%) the size of the lesion and cure 63% of the mice infected with L (L) mexicana or L (V) braziliensis as was determined by PCR. The results are indicating that both compounds may represent an alternative treatment for these two Leishmania species.

Complement Alternative Pathway Deficiency in Recipients Protects Kidney Allograft From Ischemia/Reperfusion Injury and Alloreactive T Cell Response.

Despite the introduction of novel and more targeted immunosuppressive drugs, the long-term survival of kidney transplants has not improved satisfactorily. Early antigen-independent intragraft inflammation plays a critical role in the initiation of the alloimmune response and impacts long-term graft function. Complement activation is a key player both in ischemia/reperfusion injury (IRI) as well as in adaptive antigraft immune response after kidney transplantation. Since the alternative pathway (AP) amplifies complement activation regardless of the initiation pathways and renal IR injured cells undergo uncontrolled complement activation, we speculated whether selective blockade of AP could be a strategy for prolonging kidney graft survival. Here we showed that Balb/c kidneys transplanted in factor b deficient C57 mice underwent reduced IRI and diminished T cell-mediated rejection. In in vitro studies, we found that fb deficiency in T cells and dendritic cells conferred intrinsic impaired alloreactive/allostimulatory functions, respectively, both in direct and indirect pathways of alloantigen presentation. By administering anti-fB antibody to C57 wt recipients in the early post Balb/c kidney transplant phases, we documented that inhibition of AP during both ischemia/reperfusion and early adaptive immune response is necessary for prolonging graft survival. These findings may have implication for the use of AP inhibitors in clinical kidney transplantation.

Profiling cancer gene mutations in longitudinal epithelial ovarian cancer biopsies by targeted next-generation sequencing: a retrospective study.

BACKGROUND: The majority of patients with stage III-IV epithelial ovarian cancer (EOC) relapse after initially responding to platinum-based chemotherapy, and develop resistance. The genomic features involved in drug resistance are unknown. To unravel some of these features, we investigated the mutational profile of genes involved in pathways related to drug sensitivity in a cohort of matched tumors obtained at first surgery (Ft-S) and second surgery (Sd-S). PATIENTS AND METHODS: Matched biopsies (33) taken at Ft-S and Sd-S were selected from the 'Pandora' tumor tissue collection. DNA libraries for 65 genes were generated using the TruSeq Custom Amplicon kit and sequenced on MiSeq (Illumina). Data were analyzed using a high-performance cluster computing platform (Cloud4CARE project) and independently validated. RESULTS: A total of 2270 somatic mutations were identified (89.85% base substitutions 8.19% indels, and 1.92% unknown). Homologous recombination (HR) genes and TP53 were mutated in the majority of Ft-S, while ATM, ATR, TOP2A and TOP2B were mutated in the entire dataset. Only 2% of mutations were conserved between matched Ft-S and Sd-S. Mutations detected at second surgery clustered patients in two groups characterized by different mutational profiles in genes associated with HR, PI3K, miRNA biogenesis and signal transduction. CONCLUSIONS: There was a low level of concordance between Ft-S and Sd-S in terms of mutations in genes involved in key processes of tumor growth and drug resistance. This result suggests the importance of future longitudinal analyses to improve the clinical management of relapsed EOC.

An unanticipated role for survivin in organ transplant damage.

Ischemia/reperfusion (I/R) injury is a major determinant of graft survival in kidney transplantation. Survivin, an inhibitor of apoptosis that participates in the control of mitosis and cell cycle progression, has been implicated in renal protection and repair after I/R injury; however, no study has been performed in the transplant setting. We investigated the role of survivin in modulating posttransplant I/R injury in syngeneic and allogeneic kidney grafts, and studied whether protection from I/R injury impacted on the recipient immune system, on chronic allograft nephropathy and rejection. We used genetically engineered mice with survivin haploinsufficiency and WT mice in which survivin over-expression was induced by gene-delivery. Survivin haploinsufficiency in syngeneic grafts was associated with exuberant I/R tissue injury, which triggered inflammation eventually resulting in graft loss. Conversely, survivin over-expression in the grafts minimized I/R injury and dysfunction in syngeneic grafts and in a clinically relevant fully MHC-mismatched allogeneic combination. In the latter, survivin over-expression translated into limited anti-donor adaptive immune response and less long-term allograft injury with protection from renal parenchymal damage. Our data support survivin over-expression in the graft as a novel target for protocols aimed at limiting tissue damage at the time of transplant ultimately modulating the recipient immune system.

Two patients with history of STEC-HUS, posttransplant recurrence and complement gene mutations.

Hemolytic uremic syndrome (HUS) is a disease of microangiopathic hemolytic anemia, thrombocytopenia and acute renal failure. About 90% of cases are secondary to infections by Escherichia coli strains producing Shiga-like toxins (STEC-HUS), while 10% are associated with mutations in genes encoding proteins of complement system (aHUS). We describe two patients with a clinical history of STEC-HUS, who developed end-stage renal disease (ESRD) soon after disease onset. They received a kidney transplant but lost the graft for HUS recurrence, a complication more commonly observed in aHUS. Before planning a second renal transplantation, the two patients underwent genetic screening for aHUS-associated mutations that revealed the presence of a heterozygous CFI mutation in patient #1 and a heterozygous MCP mutation in patient #2, and also in her mother who donated the kidney. This finding argues that the two cases originally diagnosed as STEC-HUS had indeed aHUS triggered by STEC infection on a genetic background of impaired complement regulation. Complement gene sequencing should be performed before kidney transplantation in patients who developed ESRD following STEC-HUS since they may be undiagnosed cases of aHUS, at risk of posttransplant recurrence. Furthermore, genetic analysis of donors is mandatory before living-related transplantation to exclude carriers of HUS-predisposing mutations.

Localization of mesenchymal stromal cells dictates their immune or proinflammatory effects in kidney transplantation.

Multipotent mesenchymal stromal cells (MSC) have recently emerged as promising candidates for cell-based immunotherapy in solid-organ transplantation. However, optimal conditions and settings for fully harnessing MSC tolerogenic properties need to be defined. We recently reported that autologous MSC given posttransplant in kidney transplant patients was associated with transient renal insufficiency associated with intragraft recruitment of neutrophils and complement C3 deposition. Here, we moved back to a murine kidney transplant model with the aim to define the best timing of MSC infusion capable of promoting immune tolerance without negative effects on early graft function. We also investigated the mechanisms of the immunomodulatory and/or proinflammatory activities of MSC according to whether cells were given before or after transplant. Posttransplant MSC infusion in mice caused premature graft dysfunction and failed to prolong graft survival. In this setting, infused MSC localized mainly into the graft and associated with neutrophils and complement C3 deposition. By contrast, pretransplant MSC infusion induced a significant prolongation of kidney graft survival by a Treg-dependent mechanism. MSC-infused pretransplant localized into lymphoid organs where they promoted early expansion of Tregs. Thus, pretransplant MSC infusion may be a useful approach to fully exploit their immunomodulatory properties in kidney transplantation.

Erythropoietin enhances immunostimulatory properties of immature dendritic cells.

Dendritic cells (DCs) are the most potent antigen-presenting cells and play a crucial role by modulating the T cell immune response against infective agents, tumour antigens and alloantigens. The current study shows that differentiating bone marrow (BM)-derived DCs but not fully differentiated DCs are targets of erythropoietin (EPO). Indeed, DCs emerging from rat bone marrow, but not splenic DCs, express the EPO receptor (Epo-R) and respond to EPO stimulation displaying a more activated phenotype with increased CD86, CD40 and interleukin (IL)-12 expression levels and a higher allostimulatory capacity on T cells than untreated DCs. Moreover, results here presented show that EPO up-regulates Toll-like receptor (TLR)-4 in differentiating DCs rendering these cells more sensitive to stimulation by the TLR-4 ligand lipopolysaccharide (LPS). Indeed, DCs treated with EPO and then stimulated by LPS were strongly allostimulatory and expressed CCR7, CD86, CD40, IL-12 and IL-23 at higher levels than those observed in DCs stimulated with LPS alone. It is tempting to speculate that EPO could act as an additional danger signal in concert with TLR-4 engagement. Thus, EPO, beyond its erythropoietic and cytoprotective effects, turns out to be an immune modulator.

Thromboxane A2 receptor blocking abrogates donor-specific unresponsiveness to renal allografts induced by thymic recognition of major histocompatibility allopeptides.

Recent in vitro studies have documented that thromboxane (Tx)A2 induces thymocyte apoptosis by acting on specific receptors abundantly expressed on the surface of immature T lymphocytes. No information is available on the in vivo relevance of this observation in development of self- or acquired tolerance. We and others have previously documented that injection of donor cells into adult thymus of experimental animals induced specific systemic unresponsiveness to allografts in the rat and mouse models. More recently, we have shown that intrathymic injection of synthetic class II major histocompatibility complex (MHC) allopeptides resulted in donor-specific unresponsiveness to renal allografts. The induction of unresponsiveness was abrogated by recipient thymectomy within the first week. We now report the effect of TxA2 blockade on acquired thymic tolerance to renal allografts induced by intrathymic injection of synthetic class II MHC allopeptides in the Wistar-Furth (WF) to Lewis rat strain combination. Administration of the TxA2 receptor blocker prior to transplantation or 2 wk postengraftment completely abrogated the unresponsive state. In addition, inhibiting the TxA2-forming enzyme by aspirin or dexamethasone also abolished the induction of acquired thymic tolerance. Evidence is also provided for a critical "dose" of peptides to be injected into the thymus to induce systemic unresponsiveness to renal allografts. These data, coupled with observations that activated peripheral T cells can circulate through the thymus, provide evidence that TxA2/TxA2 receptor interaction in the thymic microenvironment, leading to anergy/programmed cell death of activated T cells, may play an important role in the development of acquired unresponsiveness in vivo.

Thrombotic microangiopathy after kidney transplantation.

Thrombotic microangiopathy (TMA) is a severe complication of kidney transplantation that often causes graft failure. TMA may occur de novo, often triggered by immunosuppressive drugs and acute antibody-mediated rejection, or recur in patients with previous history of hemolytic uremic syndrome (HUS). Recurrent TMA is very rare in patients who had developed end-stage renal failure following HUS caused by Shiga-toxin producing E. scherichia coli, whereas disease recurrence is common in patients with atypical HUS (aHUS). The underlying genetic defect greatly impacts the risk of posttransplant recurrence in aHUS. Indeed recurrence is almost the rule in patients with mutations in genes encoding factor H or factor I, whereas patients with a mutation in membrane-cofactor-protein gene have a good transplant outcome. Prophylactic and therapeutic options for posttransplant TMA, including plasma therapy, combined kidney and liver transplantation and targeted complement inhibitors are discussed in this review.

Directed evolution of adenine base editors with increased activity and therapeutic application.

The foundational adenine base editors (for example, ABE7.10) enable programmable A•T to G•C point mutations but editing efficiencies can be low at challenging loci in primary human cells. Here we further evolve ABE7.10 using a library of adenosine deaminase variants to create ABE8s. At NGG protospacer adjacent motif (PAM) sites, ABE8s result in ~1.5× higher editing at protospacer positions A5-A7 and ~3.2× higher editing at positions A3-A4 and A8-A10 compared with ABE7.10. Non-NGG PAM variants have a ~4.2-fold overall higher on-target editing efficiency than ABE7.10. In human CD34+ cells, ABE8 can recreate a natural allele at the promoter of the γ-globin genes HBG1 and HBG2 with up to 60% efficiency, causing persistence of fetal hemoglobin. In primary human T cells, ABE8s achieve 98-99% target modification, which is maintained when multiplexed across three loci. Delivered as messenger RNA, ABE8s induce no significant levels of single guide RNA (sgRNA)-independent off-target adenine deamination in genomic DNA and very low levels of adenine deamination in cellular mRNA.

Translational mini-review series on complement factor H: therapies of renal diseases associated with complement factor H abnormalities: atypical haemolytic uraemic syndrome and membranoproliferative glomerulonephritis.

Genetic and acquired abnormalities in complement factor H (CFH) have been associated with two different human renal diseases: haemolytic uraemic syndrome and membrano proliferative glomerulonephritis. The new genetic and pathogenetic findings in these diseases and their clinical implications for the management and cure of patients are reviewed in this paper.

Genetic analysis of the complement factor H related 5 gene in haemolytic uraemic syndrome.

Several mutations in the CFH gene have been described in non-Shiga-toxin-associated haemolytic uraemic syndrome (non-Stx-HUS), a rare syndrome characterized by haemolytic anaemia, thrombocytopenia and acute renal failure. Mutations in genes encoding other complement regulatory proteins, membrane cofactor protein (CD46) and complement factor I (CFI), were also involved in the pathogenesis of the disease. Anyway, mutations in the three genes account for no more than 50% of cases of non-Stx-HUS. Human complement factor H related 5 (CFHR5) is a recently characterised member of the human complement factor H (CFH) family that has been found as a component of immune deposits in human kidney with sclerotic lesions from different causes. CFHR5 possesses cofactor activity and has been proposed to play a role in complement regulation in the glomerulus. We screened CFHR5 gene for variations potentially involved in the aetiology of HUS. Forty-five patients with HUS and 80 controls were analysed. Altogether, 5 genetic variants in CFHR5 were found in overall 9/45 HUS patients and in 4/80 controls. Statistical analysis showed that allelic variants in CFHR5 were prefentially associated with HUS. Based on these data, we conclude that, though not causative, CFHR5 genetic alterations may play a secondary role in the pathogenesis of HUS.

[Hemolytic uremic syndrome]. / La Sindrome Emolitico Uremica.

Hemolytic Uremic Syndrome (HUS) is a rare disease characterized by microangiopathic hemolytic anemia, thrombocytope-nia, and acute renal failure. HUS is most commonly triggered by Shiga-like toxin (Stx)-producing bacteria (Stx-HUS). Non-Shiga toxin-associated HUS (non-Stx-HUS) affects a heterogeneous group of patients in whom an infection by Stx-producing bacteria can be excluded as cause of the disease. It can be sporadic or familial. Biochemical evidence suggested that alterations in the complement system play an important role in the pathological mechanisms of non-Stx-HUS. Subsequently, genetic studies have shown that the disease depends on the deficiency or abnormalities in complement regulatory proteins of the alternative pathway. About 30% of the patients have mutations in the gene encoding factor H (CFH); CFH is a protein that inhibits the activation of the alternative pathway of the complement system. More recent observations have also shown the involvement of genes that encode Membrane Cofactor Protein (MCP) and factor I (CFI). Genetic studies can be useful to improve therapeutic approach. Plasma infusion or plasma exchange are helpful treatments for patients with alterations in CFH or CFI, which are plasma proteins. On the other hand, plasma treatment in patients with alterations in MCP, a membrane-bound protein, does not impact the outcome significantly. Kidney transplantation outcome is favorable in patients with MCP mutations, whereas the outcome is poor in patients with CFH and CFI mutations due to disease recurrence. During the last years, genetic studies have allowed a better comprehension of pathological molecular mechanisms. The results will offer the rationale to develop new specific treatments for HUS.

Thrombotic microangiopathy without renal involvement: two novel mutations in complement-regulator genes.

UNLABELLED: ESSENTIALS: The differential diagnosis among thrombotic microangiopathies (TMAs) is challenging. We studied a case of TMA with neurologic symptoms, no renal impairment and normal ADAMTS-13 levels. Two novel mutations in complement factor I and thrombomodulin genes were identified. Complement-regulator genes can be involved in TMAs with normal ADAMTS-13 regardless of renal damage. BACKGROUND: Thrombotic microangiopathies (TMAs) often represent a challenge for clinicians, because clinical, laboratory, and even genetic features are not always sufficient to distinguish among different TMAs. OBJECTIVES: The aim of this study was to investigate the pathogenetic mechanisms underlying an acute case of TMA with features of both thrombotic thrombocytopenic purpura (TTP) and atypical hemolytic uremic syndrome (aHUS). PATIENTS/METHODS: We report the case of a 49-year-old woman who developed an acute TMA with neurologic involvement and no renal impairment. ADAMTS-13, von Willebrand factor, and complement-system biochemical characterization was performed on acute phase samples. Exome sequencing and direct Sanger sequencing of previously aHUS-associated genes were performed. The functional consequences of the thrombomodulin (THBD) mutation were investigated by in vitro expression studies. RESULTS: Despite a clinical diagnosis of TTP, the patient had normal ADAMTS-13 levels and increased VWF antigen levels with ultra-large von Willebrand factor multimers. C3, C4, and complement factors H and I (CFI) were normal. Molecular analysis confirmed two novel heterozygous mutations in CFI (c.805G>A, p.G269S) and THBD (c.1103C>T, p.P368L), and in vitro expression studies showed a reduction in the generation of activated thrombin-activatable fibrinolysis inhibitor (TAFIa) caused by mutated THBD. This proinflammatory condition, associated with the p.G269S mutation in CFI, probably leads to a complement-mediated endothelial activation, with a relevant prothrombotic potential in case of transient environmental triggers. CONCLUSIONS: This study identified the first case of acute TMA without renal involvement but with neurological damage carrying two novel mutations in complement-regulator genes, highlighting the possible role of the complement system as a common pathogenetic mechanism in TMAs.

Immunochip analysis identifies novel susceptibility loci in the human leukocyte antigen region for acquired thrombotic thrombocytopenic purpura.

Essentials Genetic predisposition to acquired thrombotic thrombocytopenic purpura (aTTP) is mainly unknown. Genetic risk factors for aTTP were studied by Immunochip analysis and replication study. Human leukocyte antigen (HLA) variant rs6903608 conferred a 2.5-fold higher risk of developing aTTP. rs6903608 and HLA-DQB1*05:03 may explain most of the HLA association signal in aTTP. Click to hear Dr Cataland's presentation on acquired thrombotic thrombocytopenic purpura SUMMARY: Background Acquired thrombotic thrombocytopenic purpura (TTP) is a rare, life-threatening thrombotic microangiopathy associated with the development of autoantibodies against the von Willebrand factor-cleaving protease ADAMTS-13. Similarly to what has been found for other autoimmune disorders, there is evidence of a genetic contribution, including the association of the human leukocyte antigen (HLA) class II complex with disease risk. Objective To identify novel genetic risk factors in acquired TTP. Patients/Methods We undertook a case-control genetic association study in 190 European-origin TTP patients and 1255 Italian healthy controls by using the Illumina Immunochip. Replication analysis in 88 Italian cases and 456 controls was performed with single-nucleotide polymorphism (SNP) TaqMan assays. Results and conclusion We identified one common variant (rs6903608) located within the HLA class II locus that was independently associated with acquired TTP at genome-wide significance and conferred a 2.6-fold increased risk of developing a TTP episode (95% confidence interval [CI] 2.02-3.27, P = 1.64 × 10-14 ). We also found five non-HLA variants mapping to chromosomes 2, 6, 8 and X that were suggestively associated with the disease: rs9490550, rs115265285, rs5927472, rs7823314, and rs1334768 (nominal P-values ranging from 1.59 × 10-5 to 7.60 × 10-5 ). Replication analysis confirmed the association of HLA variant rs6903608 with acquired TTP (pooled P = 3.95 × 10-19 ). Imputation of classic HLA genes followed by stepwise conditional analysis revealed that the combination of rs6903608 and HLA-DQB1*05:03 may explain most of the HLA association signal in acquired TTP. Our results refined the association of the HLA class II locus with acquired TTP, confirming its importance in the etiology of this autoimmune disease.

Interleukin-6 and RANTES in Takayasu arteritis: a guide for therapeutic decisions?

BACKGROUND: In patients with Takayasu arteritis, circulating lymphocytes are activated, and histological findings indicate that cell-mediated immunity plays an important role in the pathogenetic sequence leading to vascular lesions. METHODS AND RESULTS: To delineate the profile of inflammatory and chemoattractant cytokines involved in T-cell activation in Takayasu arteritis, we measured by ELISA serum levels of interleukin (IL)-6, IL-1beta, and RANTES in 18 patients. Subsequently, we wanted to establish whether any of these molecules could be used as a marker to monitor the clinical course of the disease and to predict disease exacerbations. We found that all patients with Takayasu arteritis studied during an active phase of the disease have increased serum concentration of IL-6 compared with healthy control subjects (P<0.01). Enhanced IL-6 serum levels paralleled disease activity to the extent that its serum concentrations were comparable to those of control subjects when patients were studied in remission. RANTES concentrations were also higher than normal in the serum of all patients with Takayasu arteritis (P<0.01) studied during an active phase of the disease. RANTES serum levels tended to normalize in remission, but values remained higher than those of control subjects (P<0.05). In contrast, serum concentrations of IL-1beta were below the detection limit of ELISA in both healthy subjects and all patients with Takayasu arteritis. A positive correlation was found between either IL-6 (rho=0.705, P<0.01) or RANTES (rho=0.607, P<0.05) serum level and disease activity. CONCLUSIONS: The close correlation of serum IL-6 and RANTES levels with disease activity suggests that these cytokines contribute to vasculitic lesions in Takayasu arteritis and raises the possibility that their monitoring in serum helps clinicians find adequate treatment adjustments in individual patients.

Sequential monitoring of urine-soluble interleukin 2 receptor and interleukin 6 predicts acute rejection of human renal allografts before clinical or laboratory signs of renal dysfunction.

BACKGROUND: The significance of noninvasive techniques to the early diagnosis of acute rejection in kidney transplants remains elusive. In this study, we examined whether an early posttransplant increase in serum- and urine-soluble interleukin (IL) 2 receptor (sIL-2R) and IL-6 levels predicted acute rejection. METHODS: Sequential determinations of serum and urine sIL-2R and IL-6 were performed in the first 30 postoperative days in 40 renal transplant patients. Changes during the posttransplant period observed in 26 patients who had one or more episodes of acute rejection (group A) were compared with those recorded in 14 patients who did not experience acute rejection of their graft (group B). RESULTS: Serum sIL-2R was higher than normal in patients of groups A and B without statistical differences between the two groups. In the first 3 days after transplantation, urinary sIL-2R was higher than normal in group A but not in group B. Urinary sIL-2R at days 2 and 3 was significantly higher (P<0.05) in group A than in group B. In the first 5 days after transplantation, urinary IL-6 was persistently higher than normal in group A, whereas it progressively decreased to normal value on day 4 in group B. Sudden increases (doubling within 24 hr) in urine IL-6 preceded clinical diagnosis of acute rejection by a mean period of 2 days, with an 87% sensitivity and a 64% specificity, and also predicted recurrent rejection episodes. CONCLUSIONS: Sequential monitoring of urinary sIL-2R and IL-6 levels does allow very early diagnosis of rejection without invasive procedures. Specifically, high urinary sIL-2R in the first 5 posttransplant days identifies the subgroup of patients at risk. In the subsequent days, a sudden increase in urinary IL-6 occurs in those of the above patients who will indeed reject their graft.

Renoprotection by nitric oxide donor and lisinopril in the remnant kidney model.

Previous studies showed a renoprotective effect of l-arginine in experimental uremia. Whether this was caused by an increased nitric oxide (NO) release or depended on l-arginine per se is not clear. Here, we evaluated whether chronic administration of an NO donor, molsidomine, controlled systemic blood pressure and renal disease progression and prolonged survival in rats with renal mass reduction (RMR). Rats with RMR received the following daily in the drinking water: group 1 (n = 21), no specific therapy (vehicle); group 2 (n = 12), molsidomine, 120 mg/L; group 3 (n = 9), lisinopril, 25 mg/L; and group 4 (n = 12), reserpine, 5 mg/L, hydralazine, 80 mg/L, and hydrochlorothiazide, 25 mg/L, from day 21 after surgery, when rats had hypertension and proteinuria, until the death of the vehicle-treated rats. Molsidomine normalized systemic hypertension, only partially reduced proteinuria and serum creatinine levels, but significantly prolonged animal survival, particularly in the early stage of the disease. Lisinopril at a similar systemic blood pressure was even better than molsidomine in limiting proteinuria, preserving renal function, and prolonging survival, but triple therapy, despite being effective on blood pressure, offered no renoprotection or prolonged survival. Endothelin-1 (ET-1) levels, formed in excessive amounts by the kidneys of these animals, were reduced by molsidomine and lisinopril, but not by triple therapy. The prolongation of survival by NO donor could be attributed to its effect of reducing ET levels, which in turn may limit the smooth muscle cell proliferation and matrix accumulation responsible for organ and, especially, myocardial fibrosis in uremia.