Evaluation of the efficacy and safety of conversion to sirolimus in 85 renal transplant recipients

OBJECTIVE

Treatment with sirolimus (SRL) is a potential therapeutic option for renal transplant recipients, especially those who have developed chronic graft nephropathy (CGN) or a neoplasm. Our aim was to analyze the efficacy and safety of conversion to SRL in renal transplant recipients.

MATERIALS AND METHODS

We undertook a retrospective study of 85 patients converted to SRL, 47% for tumors, 39% for CGN, and 14% for other causes. The follow-up period was 34 months (range, 1-93 months).

RESULTS

Baseline creatinine was 1.8 +/- 0.69 mg/dL (1.6 +/- 0.59 for tumors and 2.3 +/- 0.6 for CGN). At 1 year, the creatinine was the same in both groups: 1.8 mg/dL (P = NS). Graft survival at 12 months was 89% (81% for tumors, 81% for CGN, and 100% for other causes). SRL was withdrawn in 34% of patients: 18% for severe side effects, 7% for patient death, and 9% for graft loss. The serum creatinine and proteinuria were significantly increased among those subjects who returned to dialysis because of CGN compared with those with conserved renal function. Patients who developed pneumonitis showed a lower baseline aMDRD, but no difference in SRL levels. Side effects occurred in 40% of patients, with no difference in renal function, proteinuria, or SRL levels. Renal function showed a significant improvement in the patients who continued SRL (aMDRD 45.7 vs 50.7 mL/min/1.73 m(2) at 12 months; P = .08), more marked among those who converted due to CGN. Increases were seen in levels of serum lipids, as well as in the percentage of patients treated with statins. Proteinuria increased significantly, as did the percentage of patients treated with ACE inhibitors/ARA2.

CONCLUSIONS

Conversion to SRL in patients with CGN was safe when renal function had not undergone marked worsening and there was no proteinuria. Patients who were converted experienced an improvement in renal function.

No evidence for genetic association of interferon regulatory factor 3 in systemic lupus erythematosus

The aim of this study was to determine the potential role of three IRF3 gene polymorphisms (rs2304204, rs7251 and rs2304207) with systemic lupus erythematosus (SLE). Our study population consisted of 610 patients with SLE and 730 healthy controls. All individual were of Spanish Caucasian origin. The IRF3 polymorphisms were genotyped using a PCR system with pre-developed TaqMan allelic discrimination assay. No statistically significant differences were found when allele and genotype distribution of rs2304204, rs7251 and rs2304207 polymorphisms were compared between patients with SLE and controls [overall P values: rs7251, P = 0.06; rs2304204, P = 0.26 and rs2304207, P = 0.36, by chi-squared test on a 3 x 2 contingency table. Overall allelic P values: rs7251, P = 0.8, OR (95%CI) = 1.03 (0.87-1.22); rs2304204, P = 0.2, OR (95%CI) = 1.12 (0.93-1.34) and rs2304207, P = 0.8, OR (95%CI) = 1.02 (0.82-1.26)]. In addition, no evidence of association with haplotypes and clinical features of SLE was found. Our data suggest that the IRF3 polymorphisms do not appear to play a major role in the susceptibility or severity of SLE in a Spanish population.

Investigation of TLR5 and TLR7 as candidate genes for susceptibility to systemic lupus erythematosus

OBJECTIVES

The aim of this study was to evaluate the relevance of genetic variants of TLR5 (rs5744168) and TLR7 (rs179008) gene in systemic lupus erythematosus (SLE) in a Spanish population.

MATERIAL AND METHODS

Our study population consisted of 752 SLE patients and 1107 healthy controls. All individual were of Spanish Caucasian origin. The TLR5 and TLR7 polymorphisms were genotyped using a PCR system with pre-developed TaqMan allelic discrimination assay.

RESULTS

No statistically significant differences were observed when the allele and genotype distribution of TLR5 rs5744168 and TLR7 rs179008 polymorphisms was compared between SLE patients and healthy controls. A significant increase frequency in the CC genotype of the TLR5 rs5744168 polymorphism among SLE patients without nephritis was found (93% vs. 87% in SLE patients with nephritis, p=0.03, OR=2.11 95%CI 0.93-3.51). However, this difference did not reach statistical significance in the allele frequencies (p=0.08).

CONCLUSION

These results suggest that the tested variations of TLR5 and TLR7 genes do not confer a relevant role in the susceptibility or severity to SLE in the Spanish population.

Use of cymelarsan in goats chronically infected with Trypanosoma evansi

Toxicity and therapeutic trials using Cymelarsan (an arsenical compound) against Trypanosoma evansi infection were carried out using chronically infected goats. For the toxicity trial, 40 goats were divided into four groups of 10 animals each; the first three groups received s.c. injections of 5, 10, and 15 mg/kg bw of Cymelarsan, respectively, and the last one served as control. No systemic reaction was observed in any goat throughout the experiment. For the therapeutic trial, 15 adult female goats were inoculated intravenously with at least 1 x 10(5)T. evansi isolated in the Canary Islands. Six months after inoculation, the animals were treated with Cymelarsan at single dose of 0.3 mg/kg (5 animals), 0.5 mg/kg (5 animals), and 0.625 mg/kg (5 animals). At 4 and 6 weeks after treatment, two goats belonging to 0.3 mg/kg group showed recurrence of trypanosomes. Parasitemia, however, was negative in all animals belonging to 0.5 and 0.625 mg/kg groups until the end of the experiment (6 months after treatment). Thus, it can be concluded that Cymelarsan is a safe trypanocidal drug for goats and that the curative dose is 0.5 mg/kg or above.

Comparison of an interferon-gamma assay with tuberculin skin testing for detection of tuberculosis (TB) infection in patients with rheumatoid arthritis in a TB-endemic population

OBJECTIVE

Tuberculosis (TB) in patients with rheumatoid arthritis (RA) undergoing treatment with anti-tumor necrosis factor (TNF) agents is commonly the result of reactivation of latent TB infection (LTBI); detection and treatment of LTBI is essential before treatment with anti-TNF agents. We reported previously that the tuberculin skin test (TST) is inaccurate for diagnosis of LTBI in patients with RA. Here, we compare the prevalence of LTBI in RA patients and matched controls according to positive TST and QuantiFeron-TB Gold In-Tube version (QFT) results and determine their agreement.

METHODS

A cross-sectional study of 101 RA patients and 93 controls was conducted in Lima, Perú, where the prevalence of LTBI in the general population has been estimated to be 68%. Blood was drawn for QFT assay followed by TST using 2-TU of RT 23 purified protein derivative. TST was deemed positive at >or= 5 mm for RA patients and >or= 10 mm for controls.

RESULTS

There were no significant differences between RA patients and controls for age, sex, bacillus Calmette-Guérin vaccination, or history of or contact with TB. 88% of patients had active RA disease and 2 (1.9%) patients had indeterminate QFT results. The number of subjects testing positive with the QuantiFeron assay was comparable between patients and controls (44.6% vs 59.1%, respectively), whereas the TST detected significantly less LTBI among RA patients (26.7%) than controls (65.6%). Thus, the rate of LTBI in RA patients represented 75% and 41% of the rate in their controls using QFT or TST, respectively (p = 0.008). Poor agreement between TST and QFT was seen in RA patients, but in controls, good agreement was observed between these tests.

CONCLUSION

In a TB-endemic population, the QuantiFeron-TB Gold In-Tube assay seemed to be a more accurate test for detection of LTBI in RA patients compared with the TST, and may potentially improve the targeting of prophylactic therapy before treatment with anti-TNF agents.

Conversion to Sirolimus in Posttransplant Renal Neoplasms

BACKGROUND

Calcineurin inhibitors (CNIs) have been associated with the development of posttransplant malignancies, especially lymphoma and solid organ tumors. Sirolimus (SRL) has been shown to inhibit the growth of tumor cell lines in vitro and in vivo and has proven effective in clinical practice for the treatment of Kaposi's sarcoma. Organ transplant patients treated with CNIs who develop a tumor may thus benefit from conversion to SRL.

PATIENTS AND METHODS

From December 2001 to May 2006, 25 patients who developed a tumor were converted from a CNI-based immunosuppressive regimen to SRL. We analyzed the evolution of the tumor, renal function, and the adverse effects resulting from the change of immunosuppression.

RESULTS

The mean follow-up was 19 months. Creatinine clearance (Cockcroft-Gault) increased from 59.5 +/- 21.7 to 66.0 +/- 24.2 mL/min at 12 months (P = .4) and serum cholesterol from 176.7 +/- 46.8 to 216.4 +/- 40.3 mg/dL (P = .01). Proteinuria rose from 0.3 +/- 0.1 to 1.3 +/- 0.9 g/24 hours (P = .004). Adverse events included anemia, thrombocytopenia, and oral ulcers in 20% of cases, cutaneous eruption and gastrointestinal alterations in 12%, and edema in 24%. Four (16%) patients had improved blood pressure readings. Six (24%) patients died and one experienced an acute rejection episode after conversion to SRL. Nineteen (76%) patients displayed a favorable evolution with no evidence of tumor progression.

CONCLUSIONS

Conversion to SRL stabilized tumor progression in 76% of long-term renal transplant patients who developed a neoplasm over a mean follow-up of 19 months. Moreover, renal function improved. The most important adverse effects were increased cholesterol and proteinuria.

Organic arsenic in patients (pts) with advanced solid tumors: Phase-1 results of zio-101 (s-dimethylarsino-glutathione)

3554

Background: ZIO-101(S-dimethylarsino-glutathione), a novel organic arsenic, is active against multiple cancers in vitro and in animal models. Anti-cancer activity is multifaceted and is mediated by disrupted mitochondrial function, increased reactive oxygen species (ROS) production, modified signal transduction and anti-angiogenesis. Methods: Phase-1 dose finding study to determine maximum tolerated dose (MTD), dose-limiting toxicity (DLT), pharmacokinetics (PK), and toxicities of ZIO-101 in patients with advanced solid tumors. Results: 34 pts (18 M/16 F) received 78–588 mg/m2/d IV for 5 consecutive days every 4 weeks. Median age was 61 (range, 42–79 y). Median N prior regimens was 3 (1–5). Pts had colorectal (N=17; 12 evaluable), renal (N=4), lung (N=3), melanoma (N=2), pancreas (N=2) and others (N=6). Median N of cycles was 2 (range, 1–12). MTD is 420 mg/m2/d and DLT was transient confusion, and ataxia. Fatigue, nausea and emesis were = grade-2. ZIO-101 was otherwise well-tolerated: There are no hematological toxicities and no QTc- prolongation. Five patients had stable-disease 4–12 mo (colorectal [N=3], renal [N=2],). PK studies at 420 mg/m2/d: tmax = 1 h (SD + 0.9), Cmax = 1.06 μg/L (SD ± 0.07 μg/mL), t1/2 = 17.8 h (SD ± 1.4 h) and AUC0- 8 = 25.9 mg·h/L (SD ± 0.8mg.h/L). 1 pt had complete resolution of a brain metastasis (renal) and 1 patient had a substantial decrease of a liver metastasis (pancreas). Conclusions: ZIO-101 was well tolerated. MTD is 420 mg/m2/d and DLT is transient confusion and ataxia. There was observed clinical benefit in five patients. Expansion cohort is ongoing to further test toxicities and antitumor activity. Phase II studies are ongoing.

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A gene expression signature of eventual brain metastases in patients with breast cancer

1019

Background: The incidence of brain metastases (BM) from breast cancer may be increasing, in part due to more effective systemic therapy. A metastatic signature of bone or lung metastases has been identified in mice but not for BM in human. We hypothesized that gene expression patterns of primary breast cancers may provide a specific metastatic signature for eventual BM. Methods: Core biopsies from primary breast cancers of 11 patients with BM and 12 patients who have other non-brain metastases were identified. Double- stranded cDNA was synthesized using an oligo-dT primer containing a T7 RNA polymerase promoter, followed by in vitro transcription with biotinylated ribonucleotides. The labeled cRNA was hybridized to Affymetrix U133-A chips. Results: Of the patients with BM, 55% were ER negative/HER-2 positive while 36% were ER positive/HER-2 negative. Of the patients with non brain metastases, 42% were ER negative/HER-2 positive and 50% were ER positive/HER-2 negative, with. A differential pattern of gene expression was seen in primary tumors of patients with BM when compared with those who had non-brain metastases. Many more genes were found elevated in patients with BM over what would be expected by chance (after correcting for multiple testing). Tumors that developed BM had expression of genes related to the neurological development pathways such as fetal Alzheimer antigen, MAD, neuropilin 1, and others. Several kinase pathways were involved such as protein kinase C and casein kinase substrate in neurons 2, and A kinase (PRKA) anchor protein 13. These genes will be validated in an independent set of patients with BM and non-brain metastases using real time PCR. Conclusions: The identification of genes that may predict for future development of brain metastases has many implications in terms of screening or prophylactic treatment. This would also help identify potential targets for the treatment of brain metastases.

No significant financial relationships to disclose.

The effect of recipient's age on lung transplant outcome

Selection criteria for organ transplantation have evolved over time. Age has been revisited periodically. We studied the outcome of lung transplant adjusted by age in a single center transplant population. We matched the 42 lung graft recipients older than 60 years transplanted by July 1999 to younger controls by lung disease, transplant era within 2 years, type of transplant and gender. The female to male ratios were 17/25 among the older cohort (median age 61.6 years), and 15/27 (median age 51.9 years) among the matched younger. Survival analysis demonstrated a significant difference: at 1 year, 60% versus 86%, and at 5 years, 37% versus 57%, for older and younger, respectively, p=0.005. Excess annual mortality, calculated with the declining exponential approximation to life expectancy (DEALE), showed an older/younger ratio of 1.9. Eleven deaths occurred within 6 months among the older patients, 10 due to infection. After 6 months, there were 20 more deaths, 6 due to malignancy, 5 to Bronchiolitis Obliterans Syndrome (BOS), 3 to infection and 6 to other causes. Among the younger there were 6 deaths within 6 months and 12 more thereafter; among the latter, 8 were due to BOS. Despite stringent selection, lung transplant recipients older than 60 years show increased mortality even after adjusting for their expected higher age-related mortality.

Pulmonary toxicity associated with sirolimus treatment in kidney transplantation

INTRODUCTION

An important side effect of sirolimus, a drug often used in organ transplantation, is pulmonary toxicity.

MATERIALS AND METHODS

We present five kidney transplant patients who developed this toxicity associated with sirolimus. All underwent chest radiography computed tomography, fiberoptic bronchoscopy with bronchoalveolar lavage (BAL), microbiological studies of the bronchial aspirate, blood, and sputum, and cytomegalovirus (CMV) polymerase chain reaction (PCR) in blood as well as two had transbronchial biopsies.

RESULTS

All five were men of mean age 54.8 +/- 10.3 years. In two sirolimus formed part of de novo therapy, and three were converted from calcineurin inhibitors. The mean treatment time was 16.6 +/- 13.7 months, with trough levels of 11.3 +/- 3 ng/mL. The patients presented with fever, cough, dyspnea, anemia, and dyslipidemia. The radiological pattern was diffuse alveolointerstitial (n = 2), or bilateral basal interstitial (n = 2), or bilateral basal alveolar (n = 1). The cell count in the BAL was 95% to 99% macrophages. In two patients cultures for bacteria were positive: Hemophilus and Pseudomonas. Tests for fungi, mycobacteria, pneumocystis, and legionella, as well as PCR for CMV were all negative. Transbronchial biopsy yielded insufficient material in one patient and a deposit of fibrinoid material and nonnecrotizing granuloma in the other. Antibacterial therapy was started, three with cotrimoxazole and two with ganciclovir, with no response. The respiratory symptoms improved after withdrawal of sirolimus (mean, 2.4 +/- 1.5 days). The mean hospital stay was 19.8 +/- 14.1 days.

CONCLUSION

Pulmonary toxicity due to sirolimus should be included in the differential diagnosis of kidney transplant patients who display signs of interstitial pneumonia. Its diagnosis is difficult requiring exclusion of other pulmonary diseases. Resolution of the symptoms was quick after suspension of the drug.

Vertebral osteoma in a dromedary camel

A case of vertebral osteoma observed in a female 4-year-old dromedary camel is presented. The patient showed a progressive ataxia, incoordination and finally a permanent recumbence position. Treatment was unfruitful and the animal was humanely euthanized. Postmortem examination revealed an expansive growth at vertebral body of the 10th thoracic vertebra, which was histologically classified as an osteoma. To the author's knowledge, this would be the first description of an osteoma in a camelid species.

Posttransplant Lymphoproliferative Disease: A Series of 23 Cases

Posttransplant lymphoproliferative disease (PTLD) is a rare but clinically important disorder due to its increasing incidence and its impact on renal function and the life of the patient. Between 1979 and 2005, this center performed 1614 kidney transplants, and 23 patients had PTLD. We undertook a retrospective study, analyzing risk factors, presentation, and evolution of the disorder. The most common clinical presentation was fever and adenopathy. All cases except one received calcineurin inhibitors, and nine were treated with monoclonal or polyclonal antibodies. Serology for Epstein Barr virus (EBV) was negative in nine patients at the time of transplant, and in five it became positive on diagnosis of PTLD. The predominant disorder was non-Hodgkin's lymphoma (NHL), either polymorphous (n = 11) or monomorphous (n = 7). The base therapy consisted of reducing or suspending calcineurin inhibitors and the addition of sirolimus and antivirals. Three patients received rituximab, and five chemotherapy. The disease progressed in 36% of the polymorphous NHL, in 67% of the monomorphous, and in 100% of the Hodgkin's lymphoma, whereas 10 patients had remission. Renal function worsened on diagnosis in eight patients, and the graft was infiltrated in five (confirmed histologically). Five patients lost the graft and 12 died; six due to infection and five due to PTLD. Survival was worse in the patients aged over 55 years. We conclude that in most cases EBV is positive on diagnosis of the PTLD, an age older than 55 years affords a poor prognosis, and lymphocyte infiltration of the graft is common, as is worsening renal function.

Anterior Uveitis Associated With Treatment With Intravenous Cidofovir in Kidney Transplant Patients With BK Virus Nephropathy

BACKGROUND

Polyomavirus-associated nephropathy (PVAN) is an important cause of kidney dysfunction and graft loss. Different treatment regimens have been used, including low-dose intravenous cidofovir. Anterior uveitis, a complication of this treatment, has been reported after its use in patients with cytomegalovirus-associated retinitis. We analyzed the incidence and associated risk factors for this disorder in patients with PVAN.

PATIENTS AND METHODS

The study included 14 kidney-transplant patients who had received low doses of cidofovir after being diagnosed with PVAN.

RESULTS

Five (35%) patients developed an episode of anterior uveitis. The mean number of cidofovir doses given was 6.8 +/- 1.6 as compared with 9.1 +/- 2.1 in patients who did not develop the disease. Creatinine clearance at diagnosis of the nephropathy and after terminating treatment was lower in the uveitis patients, who had a graft survival of 40% versus 100% in the patients who did not develop eye involvement. Treatment was suspended in the affected patients, with complete resolution in 80% after the administration of topical corticoids and cycloplegics.

CONCLUSIONS

Anterior uveitis secondary to low-dose treatment with cidofovir is a common complication in patients with PVAN and is associated with the degree of renal involvement. In the absence of larger studies, cidofovir should be used with caution in patients with creatinine clearance below 30 mL/min.

The effect of reflux and bile acid aspiration on the lung allograft and its surfactant and innate immunity molecules SP-A and SP-D

Gastro-esophageal reflux and related pulmonary bile acid aspiration were prospectively investigated as possible contributors to postlung transplant bronchiolitis obliterans syndrome (BOS). We also studied the impact of aspiration on pulmonary surfactant collectin proteins SP-A and SP-D and on surfactant phospholipids--all important components of innate immunity in the lung. Proximal and distal esophageal 24-h pH testing and broncho-alveolar lavage fluid (BALF) bile acid assays were performed prospectively at 3-month posttransplant in 50 patients. BALF was also assayed for SP-A, SP-D and phospholipids expressed as ratio to total lipids: phosphatidylcholine; dipalmitoylphosphatidylcholine; phosphatidylglycerol (PG); phosphatidylinositol; sphingomyelin (SM) and lysophosphatidylcholine. Actuarial freedom from BOS was assessed. Freedom from BOS was reduced in patients with abnormal (proximal and/or distal) esophageal pH findings or BALF bile acids (Log-rank Mantel-Cox p < 0.05). Abnormal pH findings were observed in 72% (8 of 11) of patients with bile acids detected within the BALF. BALF with high levels of bile acids also had significantly lower SP-A, SP-D, dipalmitoylphosphatidylcholine; PG and higher SM levels (Mann-Whitney, p < 0.05). Duodeno-gastro-esophageal reflux and consequent aspiration is a risk factor for the development of BOS postlung transplant. Bile acid aspiration is associated with impaired lung allograft innate immunity manifest by reduced surfactant collectins and altered phospholipids.

Phase-1 trial of ZIO-101, a novel organic arsenic in patients with advanced cancers

13041

Background: Arsenics are potent anti-cancer drugs. Organic arsenics are much less toxic than inorganic arsenics (like arsenic trioxide [As2O3]). We synthesized ZIO-101 (S-dimethylarsino-glutathione) by conjugating dimethylarsenic to glutathione. ZIO-101 is active against multiple cancers in in vitro tests and animals. In mice, the LD50 of ZIO-101 is about 50-fold higher than As2O3. At equimolar extracellular arsenic concentrations of ZIO-101 and As2O3, intracellular arsenic concentrations are about 15-fold higher with ZIO-101 than As2O3. In cancer cells this results in dramatically more mitochondrial damage and more apoptosis induction. Preclinical data suggest ZIO-101 may induce apoptosis by different mechanisms than As2O3 and can kill As2O3-resistant cancer cells. Methods: A phase-1 study evaluating the safety and pharmacokinetic profile of ZIO-101 in pts with advanced cancers. 18 patients enrolled in 5 cohorts. Mean Age 63 (42–79). Starting dose was 78 mg/m2/d IV for 5 days every month with 40% dose increases. Results: Thirty-three courses of ZIO-101 have been delivered. Therapy with ZIO-101 was safe. Toxicities ≥ grade-2 include Fatigue (N = 4), Vomiting (N = 4), and Anorexia (N = 2). One patient with rapidly progressing metastatic renal cell cancer had complete resolution of a brain metastasis and stable disease elsewhere (beyond 6 months). Pharmacokinetic (PK) studies at 214 mg/m2/d showed a tmax = 1 h (no SD), Cmax = 685 μg/mL (SD ± 130 μg/mL), t1/2 = 13.9 h (SD ± 0.3 h) and AUC0-∞ = 14.9 μg.h/mL (SD ± 2.6μg.h/mL). Conclusions: Clinical and PK data show ZIO-101 is safe at doses that result in blood levels that have substantial anti-cancer activity at in vivo concentrations. There is early evidence of clinical activity. Dose-escalation continues. Results on subsequent dose-levels will be presented.

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Pre-implantation multiple cytokine mRNA expression analysis of donor lung grafts predicts survival after lung transplantation in humans

While current donor selection with clinical findings is generally effective, the imprecise nature of the assessment forces clinicians to remain on the conservative side. A reliable biological marker would assist donor selection and would improve donor organ utilization. We collected biopsies from 169 donor lungs before implantation. Expression levels of IL-6, IL-8, IL-10, TNF-alpha, IFN-gamma and IL-1beta were measured by quantitative real-time RT-PCR (qRT-PCR). Seventeen cases died within 30 days after transplantation. No donor factor was significantly associated with 30-day mortality. Univariate analysis of the 84 cases for development of the prediction model showed that IL-6, IL-8, TNF-alpha and IL-1beta were risk factors for mortality and IL-10 and IFN-gamma were protective factors. We analyzed the cytokine expression ratios of risk to protective cytokines. A stepwise logistic regression for 30-day mortality demonstrated that a model containing the ratio of IL-6/IL-10 was the most predictive (p = 0.0013). When applied to the remaining 85 cases for validation, the test of model fit was significant (p = 0.039). Using the cytokine ratio, we were able to define three risk groups with striking differences in survival (p = 0.0003). Multi-cytokine analysis of the donor lung graft with qRT-PCR shows significant promise as a strategy to biologically evaluate the donor lung prior to implantation.

Potential involvement of galectin-3 and SNAP23 in Aeromonas hydrophila cytotoxic enterotoxin-induced host cell apoptosis

We investigated the potential of the cytotoxic enterotoxin (Act) of Aeromonas hydrophila to bind to 1869 human and 4319 yeast proteins, using protein microarray technology. Act was capable of binding nine different human proteins, including the SNARE complex scaffolding protein synaptosomal-associated protein 23 (SNAP23), galectin-3, and guanylate kinase 1 (GUK-1). Act was also able to bind to four of the yeast proteins examined, which included the vesicle tethering protein Vsp52. We verified interaction of Act with murine and human SNAP23, galectin-3, and GUK-1 by sandwich Western blot analysis. In order to determine the physiological relevance of Act binding to these three proteins, we performed small interfering RNA (siRNA) gene knockdown experiments in RAW 264.7 cells, a murine macrophage cell line in which Act-induced signaling and cell death is well characterized. Based on real-time reverse transcriptase-polymerase chain reaction, siRNA transfection of RAW 264.7 cells with specific oligonucleotides reduced the expression of genes encoding SNAP23, galectin-3, and GUK-1 by 62, 63, and 99%, respectively. Knockdown of galectin-3 and SNAP23, but not GUK-1, significantly reduced Act-induced apoptosis of host cells, as determined by TUNEL (TdT-mediated dUTP nick end labeling) assay, lactate dehydrogenase release, Giemsa staining, and reduction in activation of caspase 3, compared to toxin-treated macrophages that were transfected with a random sequence control siRNA. We also performed these assays using a human intestinal epithelial cell line (HT-29) and observed a similar trend of galectin-3 and SNAP23 association with Act-induced apoptosis. This is the first report of putative protein binding partners for this toxin and potential mediators/regulators of Act-induced apoptosis.

Impact of lung transplant operation on bronchiolitis obliterans syndrome in patients with chronic obstructive pulmonary disease

Previous studies suggest that bilateral (BLT) compared with single lung transplantation (SLT) for patients with chronic obstructive pulmonary disease (COPD) results in improved long-term survival. The effect of transplant operation on bronchiolitis obliterans syndrome (BOS) is unknown. A retrospective study of all lung transplant recipients with pre-transplant diagnoses of COPD at the University of Toronto and at Duke University was performed. Data collected were age, gender, date and type of transplant, acute rejection, survival, presence and time of BOS. 221 (bilateral n = 101, single n = 120) patients met our criteria. Patients with BLT were younger (53.0 vs. 55.3 years; p = 0.034), more likely to be male (56.3% vs. 42.4%; p = 0.039) and more likely to be transplanted at the University of Toronto (79.6% vs. 16.1%; p < 0.001). Freedom from BOS was similar at 1 year post-transplant. However, BLT recipients were more commonly free from BOS 3 years (57.4% vs. 50.7%) and 5 years (44.5% vs. 17.9%) post-transplant (p = 0.024). Survival of BLT was better than SLT recipients at 3 and 5 years post-transplant (BLT vs. SLT: 67.5% vs. 61.1% and 60.7% vs. 34.1%, respectively; p = 0.018). Similar trends on survival were observed after development of BOS. BLT results in lower rates of BOS in patients with COPD that are eligible for both SLT and BLT.