Immunoglobulin glycation with fructose: a comparative study

BACKGROUND: Immunoglobulins undergo non-enzymatic glycation reaction with sugars both in vivo and in vitro. Effects of glycation on the ability of the antibodies to bind antigens are contradictory. Antibodies raised in various animals may also be exposed to high concentration of sugars that are added during freeze-drying/pasteurization for preservation. METHODS: IgG isolated from the sera of goat, human, rabbit, mouse, buffalo as well as IgY from hen egg yolk was subjected to in vitro glycation with fructose. The behavior of glycated IgG was investigated by SDS-PAGE, hyperchromicity at 280 nm, tryptophan fluorescence and new fluorescence. RESULTS: Marked variations were observed in the response of the immunoglobulins derived from various animals to incubation with fructose. Also, incubation of anti-glucoseoxidase (GOD) antibodies with fructose resulted in a rapid loss of their ability to bind the enzyme antigen as revealed by immunodiffusion and ELISA. DETAPAC and EDTA were quite protective but were unable to completely prevent the fructose-induced alterations. CONCLUSIONS: Immunoglobulins derived from goat, human, rabbit, mouse, buffalo and hen egg yolk undergo remarkable structural alterations on incubation with fructose. The susceptibility of the immunoglobulins to the modification however differed remarkably. The goat IgG was most recalcitrant while hen egg yolk IgY was most susceptible to the alterations. DETAPAC or EDTA restricted the fructose-induced alterations remarkably.     

Acute humoral rejection in kidney transplantation: II. Morphology, immunopathology, and pathologic classification

The incidence of acute humoral rejection (AHR) in renal allograft biopsies has been difficult to determine because widely accepted diagnostic criteria have not been established. C4d deposition in peritubular capillaries (PTC) of renal allografts has been proposed as a useful marker for AHR. This study was designed to test the relative value of C4d staining, histology, and serology in the diagnosis of AHR. Of 232 consecutive kidney transplants performed at a single institution from July 1995 to July 1999, all patients (n = 67) who developed acute rejection within the first 3 mo and had a renal biopsy with available frozen tissue at acute rejection onset, as well as posttransplant sera within 30 d of the biopsy, were included in this study. Hematoxylin and eosin and periodic acid-Schiff stained sections were scored for glomerular, vascular, and tubulointerstitial pathology. C4d staining of cryostat sections was done by a sensitive three-layer immunofluorescence method. Donor-specific antibodies (DSA) were detected in posttransplant recipient sera using antihuman-globulin-enhanced T cell and B cell cytotoxicity assays and/or flow cytometry. Widespread C4d staining in PTC was present in 30% (20 of 67) of all acute rejection biopsies. The initial histologic diagnoses of the C4d(+) acute rejection cases were as follows: AHR only, 30%; acute cellular rejection (ACR) and AHR, 45%; ACR (CCTT types 1 or 2) alone, 15%; and acute tubular injury (ATI), 10%. The distinguishing morphologic features in C4d(+) versus C4d(-) acute rejection cases included the following: neutrophils in PTC, 65% versus 9%; neutrophilic glomerulitis, 55% versus 4%; neutrophilic tubulitis, 55% versus 9%; severe ATI, 75% versus 9%; and fibrinoid necrosis in glomeruli, 20% versus 0%, or arteries, 25% versus 0%; all P < 0.01. Mononuclear cell tubulitis was more common in the C4d(-) group (70% versus 100%; P < 0.01). No significant difference between C4d(+) and C4d(-) acute rejection was noted for endarteritis, 25% versus 32%; interstitial inflammation (mean % cortex), 27.2 +/- 27% versus 38 +/- 21%; interstitial hemorrhage, 25% versus 15%; or infarcts, 5% versus 2%. DSA were present in 90% (18 of 20) of the C4d(+) cases compared with 2% (1 of 47) in the C4d(-) acute rejection cases (P < 0.001). The pathology of the C4d(+) but DSA(-) cases was not distinguishable from the C4d(+), DSA(+) cases. The C4d(+) DSA(-) cases may be due to non-HLA antibodies or subthreshold levels of DSA. The sensitivity of C4d staining is 95% in the diagnosis of AHR compared with the donor-specific antibody test (90%). Overall, eight grafts were lost to acute rejection in the first year, of which 75% (6 of 8) had AHR. The 1-yr graft failure rate was 27% (4 of 15) for those AHR cases with only capillary neutrophils versus 40% (2 of 5) for those who also had fibrinoid necrosis of arteries. In comparison, the 1-yr graft failure rates were 3% and 7%, respectively, in ACR 1 (Banff/CCTT type 1) and ACR 2 (Banff/CCTT type 2) C4d(-) groups. A substantial fraction (30%) of biopsy-confirmed acute rejection episodes have a component of AHR as judged by C4d staining; most (90%), but not all, have detectable DSA. AHR may be overlooked in the presence of ACR or ATI by histology or negative serology, arguing for routine C4d staining of renal allograft biopsies. Because AHR has a distinct therapy and prognosis, we propose that it should be classified separately from ACR, with further sub-classification into AHR 1 (neutrophilic capillary involvement) and AHR 2 (arterial fibrinoid necrosis).     

BK virus-associated nephropathy in sirolimus-treated renal transplant patients: incidence, course, and clinical outcomes

BACKGROUND: Because the course of polyoma virus-associated nephropathy (PVAN) has not been evaluated in a large cohort of patients receiving sirolimus (SRL)-based regimens, we have herein presented the incidence, clinical characteristics, and outcomes of 378 renal transplant recipients treated with SRL-based immunosuppression. METHODS: This retrospective single center study evaluated 344 kidney alone (KTX) and 34 simultaneous pancreas-kidney (SPK) transplantations performed between June 2000 and December 2004. RESULTS: At a mean follow-up of 43.3 months, six kidney (1.7%) and three kidney-pancreas (9.0%) transplanted patients displayed biopsy-proven PVAN. The mean time to diagnosis after transplantation was 18.2 months (range: 3.5-31.1 months), with a higher incidence among patients exposed (4.23%) versus not exposed to rabbit antithymocyte globulin (rATG; 0.53%; P=0.019) or SPK (9.0%) versus KTX (1.7%) recipients (odds ratio: 5.43; confidence interval: 1.29-22.8; P=0.038). Despite treatment with cidofovir, reduced immunosuppression and maintenance therapy with no agents other than SRL (C0=10.2+/-2.7 ng/dL) plus modest doses of prednisone (< or =5 mg), five patients (55.5%) experienced renal allograft failure. No rejection episodes were documented during the PVAN treatment and pancreatic function continued to be excellent among the SPK patients. CONCLUSIONS: Patients treated with SRL-based immunosuppression showed an incidence at the lower end of the range described with various other contemporaneous immunosuppressive regimens and with other cohorts not undergoing BK virus polymerase chain reaction surveillance. Exposure to rATG and SPK transplantation represented risk factors for the occurrence of PVAN, which showed a pernicious course despite withdrawal of calcineurin antagonists and/or mycophenolate mofetil.     

Longitudinal assessment of health related quality of life of HIV infected patients treated for tuberculosis and HIV in a high burden setting

Introduction

Assessment of patients receiving treatment for human immunodeficiency virus (HIV) and tuberculosis (TB) using a Health Related Quality of Life (HRQoL) instrument is important to get the subjective view of the patients’ wellbeing.

Methods

We used the Functional Assessment of HIV Infection (FAHI) HRQoL instrument to collect perceived wellness information at baseline, month 3, 6 and 12 from patients enrolled in a pharmacokinetic study between March 2007 and April 2008. Composite domain scores at each time point and their relationship with the rate of adverse events (AEs) and serious adverse events were compared between treatment arms.

Results

Out of the 82 patients enrolled, 76 were analysed. There was a significant increase in total score in all groups between baseline, month 3, 6 and 12 (all p values < 0.0001), and over time (p < 0.001). Adjusting for baseline total score, baseline CD4 count had a significant effect on the total score over time (p = 0.002) and the rate of change in total score over time, that is; interaction effect (p < 0.001). There was no difference in each domain scores between participants that received ART with TB treatment and those that received TB treatment only. Respiratory AEs had a significant effect on HRQoL.

Conclusion

We found that assessment of HRQoL of participants in TB–HIV treatment using the FAHI instrument was useful in evaluating treatment responses. It showed improvement consistent with decrease in adverse events and signs and symptoms of TB. Number and type of AEs was related to lower HRQoL in spite of TB cure.

     

Synthesis of new pyridines with sulfonamide moiety via a cooperative vinylogous anomeric-based oxidation mechanism in the presence of a novel quinoline-based dendrimer-like ionic liquid

In the present study, we reported the synthesis of a novel quinoline-based dendrimer-like ionic liquid. After characterization of the mentioned ionic liquid with suitable techniques such as Fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray spectroscopy (EDX), elemental mapping, thermogravimetric analysis (TGA) and derivative thermogravimetry (DTG), its catalytic performance was investigated in the synthesis of new pyridines with sulfonamide moiety via a cooperative vinylogous anomeric-based oxidation mechanism under mild reaction conditions. All target molecules were achieved in short reaction times and high yields.

In the present study, we reported the synthesis of a novel quinoline-based dendrimer-like ionic liquid and investigated its catalytic performance for the synthesis of new pyridines with sulfonamide moieties via a cooperative vinylogous anomeric-based oxidation mechanism.     

Posttransplant lymphoproliferative disorder associated with an Epstein-Barr-related virus in cynomolgus monkeys

BACKGROUND: Human posttransplant lymphoproliferative disorder (PTLD) has been shown to be associated with Epstein-Barr virus (EBV) infection. Primate animal models of PTLD and the use of molecular markers in its diagnosis have not been reported. This study was designed to evaluate the frequency, pathology, and molecular characteristics of PTLD in cynomolgus kidney allograft recipients. METHODS: Over a 5-year period (January 1995 to November 2000), 160 primate renal transplants were performed at the Massachusetts General Hospital (MGH). Of these, all cases (n=9) that developed PTLD were included. H&E stained paraffin sections of all available tissue samples from the cases were evaluated for the presence of PTLD. Immunoperoxidase staining for T cells (CD3), B cells (CD20), kappa and lambda light chains as well as EBV nuclear antigens (EBNA2) and latent membrane proteins (EBV LMP-1) was done on paraffin sections using standard immunohistochemical (IHC) methods. In situ hybridization for EBV encoded RNA (EBER) was performed in all tissue samples with atypical lymphoid proliferations, using a novel EBER nucleotide probe based on consensus gene sequences from EBV and the related herpes lymphocryptoviruses (LCV) infecting baboons and rhesus macaques. RESULTS: Of 160 consecutive primate renal transplants performed at MGH, 5.6% developed PTLD 28-103 days after transplantation. In all cases, the lymph nodes were involved and effaced by an atypical polymorphous lymphoid proliferation of EBER+ B cells, diagnostic for PTLD. Focal staining for EBNA-2 was noted in tumor cells. In 67% (six of nine) the PTLD infiltrates were present in extra nodal sites, notably liver (56%), lung (44%), heart (44%), renal allograft (44%), and native kidney (22%). The spleen was involved by PTLD in all four animals that had not undergone a pretransplant splenectomy. The PTLD morphology was similar in all cases and predominantly of the polymorphous type, however, some of these showed areas that appeared minimally polymorphous. No cases of monomorphic PTLD were seen. CONCLUSIONS: By in situ hybridization, expression of the RNA product, homologous for EBV-encoded RNA (EBER) was identified in the PTLD tumor cells of all cases, indicating latent primate EBV- related infection. This report identifies a novel animal model of EBV associated PTLD in the setting of kidney transplantation, with valuable implications for managing and understanding human PTLD and oncogenesis.     

Pulmonary exposure to metallic nanomaterials during pregnancy irreversibly impairs lung development of the offspring

Due to the growing commercial applications of manufactured nanoparticles (NPs), toxicological studies on NPs, especially during the critical window of development, are of major importance. The aim of the study was to assess the impact of respiratory exposure to metallic and metal oxide NPs during pregnancy on lung development of the offspring and to determine the key parameters involved in lung alterations. Pregnant mice were exposed to weekly doses of 100?μg (total dose 300?μg) of titanium dioxide (TiO₂), cerium oxide (CeO₂), silver (Ag) NPs or saline solution by nonsurgical intratracheal instillation. The offspring lungs were analyzed at different stages of lung development: fetal stage (gestational day 17.5), pulmonary alveolarization (post-delivery day 14.5) and lung maturity (post-delivery day 49.5). Regardless of the type of NP, maternal exposure during gestation induced long-lasting impairment of lung development of the offspring. This effect was accompanied by: i) decreased placental efficiency together with the presence of NPs in placenta, ii) no increase of inflammatory mediators present in amniotic fluid, placenta or offspring lungs and iii) decreased pulmonary expression of vascular endothelial growth factor-α (VEGF-α) and matrix metalloproteinase 9 (MMP-9) at the fetal stage, and fibroblast growth factor-18 (FGF-18) at the alveolarization stage. Respiratory exposure to metallic NPs during pregnancy induces stereotyped impairment of lung development with a lasting effect in adult mice, independently of the chemical nature of the NP.     

A protective role for IL-6 in staphylococcal microbial keratitis

PURPOSE: To determine whether interleukin-6 (IL-6) plays a protective role in Staphylococcus aureus keratitis in a gene knockout (gko) mouse model and to determine whether IL-6 may be used as a therapy to modulate host responses and control bacterial infection, thereby reducing scarring. METHODS: The eyes of IL-6 gko mice and wild-type mice were challenged topically with S. aureus and examined at 24 hours after infection. Keratitis was examined clinically and histologically. Bacterial and polymorphonuclear leukocytes (PMNs) were enumerated, and cytokine and chemokine levels were determined by ELISA. Exogenous IL-6 was administered to both IL-6 gko and wild-type mice, and clinical parameters were determined. RESULTS: IL-6 gko mice showed more severe disease, with increased bacterial counts and PMNs, than did wild-type mice. Changes in levels of chemokines and cytokines were also observed. Administration of exogenous IL-6 resulted in an improved outcome in IL-6 gko mice, with a threefold reduction in bacterial load. CONCLUSIONS: The data suggest an important regulatory role for IL-6 in modulating excessive inflammatory responses and in controlling bacterial proliferation. IL-6 may play a role in the priming and activation of neutrophils. It could represent a broad-spectrum therapy to improve outcomes in patients who have these potentially blinding infections.