Right ventricle dimensions and function in response to acute hypoxia in healthy human subjects.

AIM: Acute hypoxia produces acute vasoconstriction in the pulmonary circulation with consequences on right ventricular (RV) structure and function. Previous investigations in healthy humans have been restricted to measurements after altitude acclimatization or were interrupted by normoxia. We hypothesized that immediate changes in RV dimensions in healthy subjects in response to normobaric hypoxia differ without the aforementioned constraints. METHODS: Transthoracic echocardiography was performed in 35 young, healthy subjects exposed to 11% oxygen, as well as six controls under sham hypoxia (20.6% oxygen, single blind) first at normoxia and after 30, 60, 100, 150 min of hypoxia or normoxia respectively. A subgroup of 15 subjects continued with 3-min cycling exercise in hypoxia with subsequent evaluation followed by an assessment 1 min at rest while breathing 4 L min-1 oxygen. RESULTS: During hypoxia, there was a significant linear increase of all RV dimensions (RVD1 + 29 mm, RVD2 + 42 mm, RVD3 + 41 mm, RVOT + 13 mm, RVEDA + 18 mm, P < 0.01) in the exposure group vs. the control group. In response to hypoxia, right ventricular systolic pressure (RVSP) showed a modest increase in hypoxia at rest (+7.3 mmHg, P < 0.01) and increased further with physical effort (+11.8 mmHg, P < 0.01). After 1 min of oxygen at rest, it fell by 50% of the maximum increase. CONCLUSION: Acute changes in RV morphology occur quickly after exposure to normobaric hypoxia. The changes were out of proportion to a relatively low-estimated increase in pulmonary pressure, indicating direct effects on RV structure. The results in healthy subjects are basis for future clinically oriented interventional studies in normobaric hypoxia.

Laparoscopic retroperitoneal repair of a right-sided Bochdalek hernia.

Bochdalek hernias are rare congenital diaphragmatic defects. We report a case of a 50-year-old male with chronic shortness of breath who was diagnosed with a right-sided Bochdalek hernia. This hernia was repaired using a laparoscopic retroperitoneal approach.

Diaphragm pacing with natural orifice transluminal endoscopic surgery: potential for difficult-to-wean intensive care unit patients.

BACKGROUND: Up to 50% of the patients in the intensive care unit (ICU) require mechanical ventilation, with 20% requiring the use of a ventilator for more than 7 days. More than 40% of this time is spent weaning the patient from mechanical ventilation. Failure to wean from mechanical ventilation can in part be attributable to rapid onset of diaphragm atrophy, barotrauma, posterior lobe atelectasis, and impaired hemodynamics, which are normally improved by maintaining a more natural negative chest pressure. The authors have previously shown that laparoscopic implantation of a diaphragm pacing system benefits selected patients. They now propose that an acute ventilator assist with interventional neurostimulation of the diaphragm in the ICU is feasible and could facilitate the weaning of ICU patients from mechanical ventilation. Natural orifice transluminal endoscopic surgery (NOTES) has the potential to expand the benefits of the diaphragm pacing system to this acute patient population by allowing it to be performed at the bedside similarly to insertion of the common gastrostomy tube. This study evaluates the feasibility of this approach in a porcine model. METHODS: Pigs were anesthetized, and peritoneal access with the flexible endoscope was obtained using a guidewire, needle knife cautery, and balloon dilation. The diaphragm was mapped using a novel endoscopic electrostimulation catheter to locate the motor point (where stimulation provides complete contraction of the diaphragm). An intramuscular electrode then was placed at the motor point with a percutaneous needle. The gastrotomy was managed with a gastrostomy tube. RESULTS: Four pigs were studied, and the endoscopic mapping instrument was able to map the diaphragm to identify the motor point. In one animal, a percutaneous electrode was placed into the motor point under transgastric endoscopic visualization, and the diaphragm could be paced in conjunction with mechanical ventilation. CONCLUSIONS: These animal studies demonstrate the feasibility of transgastric mapping of the diaphragm and implantation of a percutaneous electrode for therapeutic diaphragmatic stimulation.

Cost-minimization analysis of treprostinil vs. epoprostenol as an alternate to oral therapy non-responders for the treatment of pulmonary arterial hypertension.

INTRODUCTION: Idiopathic pulmonary arterial hypertension (IPAH) is associated with substantial morbidity and mortality. Treprostinil was compared to epoprostenol for the economic impact of treating IPAH patients who failed or were not candidates for bosentan. METHODS: The model was a cost-minimization analysis, assuming clinical equivalence was achieved by proper dosing of both drugs, in terms of survival and surrogate measures. Two theoretical cohorts of 270 patients were treated with subcutaneous treprostinil and intravenous epoprostenol, and were evaluated over 3 years using a spreadsheet model. Annual survival rates were estimated for the cohorts so that at endpoint 114 (42%) patients survived in both groups. The model utilized resource valuation data for medication and supply costs from Medicare; hospital, consultation, surgical, and diagnostic procedural fees from North Carolina hospitals; and costs to treat adverse events from published sources. Costs were obtained from standard lists and were presented as 2003 US dollars, discounted at 3%. Sensitivity analyses were performed testing all model uncertainties. RESULTS: In the base case analysis, treprostinil demonstrated savings of 22,701 US dollars and 37,433 US dollars per patient over 1- and 3-year time horizons, respectively. The greatest savings came from reduced or minimal hospitalizations attributed to the dose titration and treatment of adverse events, such as sepsis, associated with epoprostenol and its delivery system. Probabilistic sensitivity analyses resulted in average 3-year cost-savings of 41,051 US dollars (Standard Deviation = 13,902 US dollars) per patient. CONCLUSIONS: By initiating and continuing treatment with treprostinil over a 3-year period, the economic burden associated with IPAH may be reduced compared to treatment with epoprostenol. The greatest saving with treprostinil was attributed to decreased sepsis.

The 6-min walk test (6MW) as an efficacy endpoint in pulmonary arterial hypertension clinical trials: demonstration of a ceiling effect.

BACKGROUND: PAH trials traditionally use 6MW as the primary endpoint. Concerns regarding a "ceiling effect" masking efficacy have led to exclusion of patients with milder disease from most trials (BL 6MW>450 m). STRIDE I evaluated the selective endothelin A receptor antagonist, sitaxsentan (SITAX), in a 12-week randomized, double-blind, trial (178 patients) employing placebo (PBO), 100 mg or 300 mg SITAX orally once daily in PAH and included patients with NYHA class II, congenital heart disease and a BL 6MW>450 m, groups often excluded from previous trials. METHODS: We analyzed 6MW effects For All Pts (intention-to treat) and those meeting Traditional enrollment criteria, defined as patients with NYHA class III or IV and 6MW< or =450 m at BL with idiopathic PAH or PAH related to connective tissue disease. The 100 mg and 300 mg SITAX arms are pooled based on similar treatment effects on 6MW. CONCLUSION: Existence of a "ceiling effect" is supported by these data. The magnitude of the treatment effect and statistical power when using 6MW as the endpoint. Comparisons between PAH trials that do not adjust for the effects of differing enrollment criteria require caution.

Clinical characteristics of 13 solid organ transplant recipients with ganciclovir-resistant cytomegalovirus infection.

BACKGROUND: Ganciclovir-resistant (GCV-R) cytomegalovirus (CMV) is now being reported with increasing frequency in solid organ transplant recipients. OBJECTIVE: To describe the clinical characteristics and outcomes of all solid organ transplant patients with GCV-R CMV seen between 1990 and 2000 at a single center. METHODS: Patients with clinically suspected GCV resistance had viral isolates subjected to phenotypic analysis by plaque reduction assay, and also genotypic analysis. Medical records of the 13 patients with GCV-R CMV were reviewed for demographic, microbiologic, clinical, and pathologic data. RESULTS: Thirteen patients were identified, including 5 kidney, 1 heart, and 7 lung transplant recipients. All but one patient (92%) were CMV donor seropositive, recipient negative (D+/R-), and 11/13 (85%) had tissue-invasive CMV. CMV viremia was recurrent in 9/13 (69%); in 2 others, the first CMV episode was fatal. Overall, 9/13 (69%) of patients have died, all of CMV or its complications. Of the 10 who received foscarnet, only one survived. All patients had received GCV-based prophylactic regimens; 8/13 patients (62%) had received CMV hyperimmune globulin (CMVIG) as part of prophylaxis, 6/13 (46%) had received oral ganciclovir, and 5/13 (38%) had received intermittent (3 x/week) IV ganciclovir for prophylaxis. CONCLUSIONS: GCV-R CMV is associated with CMV D+/R- status, tissue-invasive disease, and high mortality even with foscarnet therapy. Exposure to less than fully therapeutic levels of GCV, in the form of oral or intermittent IV GCV, is common. The use of CMVIG in prophylaxis does not appear to prevent resistance. Further work remains to be done to elucidate the risk factors and optimal mode of prophylaxis and treatment for GCV-R CMV.

The incidence of invasive aspergillosis among solid organ transplant recipients and implications for prophylaxis in lung transplants.

BACKGROUND: Invasive aspergillosis (IA) is associated with significant morbidity and mortality in solid organ transplant recipients but data on the incidence rates stratified by type of solid organ are limited. OBJECTIVE: To describe the attack rates and incidence of IA in solid organ transplant recipients, and the impact of universal Aspergillus prophylaxis (aerosolized amphotericin B or oral itraconazole) in lung transplant recipients. PATIENTS: The 2,046 patients who received solid organ transplants at the Cleveland Clinic Foundation from January 1990 through 1999 were studied. METHODS: Cases were ascertained through computerized records of microbiology, cytology, and pathology reports. Definite IA was defined as a positive culture and pathology showing septate hyphae. Probable IA was clinical disease and either a positive culture or histopathology. Disseminated IA was defined as involvement of two or more noncontiguous anatomic sites. RESULTS: We identified 33 cases of IA (28% disseminated) in 2,046 patients (attack rate = 1.6%) for an incidence of 4.8 cases per 1,000 patient-years (33 cases/6,813 pt-years). Both the attack and the incidence rates were significantly higher for lung transplant recipients vs. other transplant recipients: lung 12.8% (24 cases/188 patients) or 40.5 cases/1,000-pt year vs. heart 0.4% (3/686) or 1.4 per 1,000-pt year vs. liver 0.7% (3/439) or 2.1 per 1,000-pt year vs. renal 0.4% (3/733) or 1.2 per 1,000-pt year (P < 0.01). The incidence of IA was highest during the first year after transplantation for all categories, but cases occurred after the first year of transplantation only in lung transplant recipients. The attack rate of IA in lung transplant recipients was significantly lower after institution of routine Aspergillus prophylaxis (4.9% vs. 18.2%, P < 0.05). CONCLUSIONS: The highest incidence and attack rate of invasive aspergillosis among solid organ transplant recipients occurs in lung transplant recipients and supports the routine use of Aspergillus prophylaxis for at least one year after transplantation in this group.

Enhanced cyclosporine-itraconazole interaction with cola in lung transplant recipients.

BACKGROUND: Invasive aspergillosis is a major cause of morbidity and mortality in lung transplant recipients (LTR), occurring in up to 15% of patients post-transplant. The 14% aspergillus incidence at the Cleveland Clinic Foundation prompted institution of universal prophylaxis with oral itraconazole (ICZ) in 1997. We report our experience with two protocols of ICZ administration in non-cystic fibrosis LTR and the interaction with cyclosporine (CSA). METHODS: Group 1 patients (n=12) were administered ICZ capsules in a fasting or fed state, with or without a histamine-2 (H-2) receptor antagonist or proton pump inhibitor. Group 2 patients (n=12) received the same protocol as group I, but in a fed state with a carbonated beverage (cola) to increase acidity in the stomach to enhance absorption of ICZ. The ICZ dose was 200 mg/d, given as one daily dose. A historical control group (n=10) did not receive chemoprophylaxis with ICZ. CSA daily doses, dose intervals, concentration, cost, and random ICZ levels were documented over a 4-month period of time and compared using generalized estimating equations. RESULTS: The daily CSA mg/kg/d dose decreased over time in all three groups, but no differences were found between the three groups. The CSA dosing interval over time was significantly prolonged in group 2 compared to group 1 or the control group (p< or =0.003). Over time, there was no difference in CSA concentration between all groups. There was no difference in cost over time between the three groups; however, the mean cost of CSA therapy was significantly lower in group 2 compared to the control group (p=0.025). Group 2 administered ICZ with cola had greater random blood concentrations of ICZ (p=0.019). CONCLUSIONS: ICZ capsules administered in a fed state with a cola resulted in greater random levels of ICZ, a decrease in cost/d of CSA, and a prolongation of CSA dosing interval. Although daily CSA dosage trended lower in group 2, it did not reach statistical significance. We believe these changes in CSA dosing over time reflect increased absorption of ICZ and recommend verifying ICZ absorption with an itraconazole level, especially when CSA intervals are not prolonged.

Hypogammaglobulinemia in lung transplant recipients.

BACKGROUND: Infectious complications continue to represent a significant source of morbidity and mortality in lung transplant recipients. Identifying specific, remediable immune defects is of potential value. After one lung transplant patient with recurrent infections was noted to be severely hypogammaglobulinemic, a screening program for humoral immune defects was instituted. The objectives were to define the prevalence of hypogammaglobulinemia in lung transplant recipients, assess levels of antibody to specific pathogens, and correlate infectious disease outcomes and survival with immunoglobulin levels. METHODS: All lung transplant recipients followed at a single center between October 1996 and June 1999 underwent a posttransplant humoral immune status survey as part of routine posttransplant follow-up. This survey consists of total immunoglobulin levels (IgG, IgM, IgA), IgG subclasses (IgG1-4), and antibody titers to Pneumococcus, diphtheria, and tetanus. Since February 1997, this survey has been incorporated into the pretransplant evaluation as well. Humoral survey results for October 1996 through July 1999 were recorded, and clinical information on major infectious disease outcomes was obtained from chart reviews, discharge summaries, the Cleveland Clinic Unified Transplant Database, and review of all microbiological studies and pathology results for each patient. RESULTS: Of 67 patients with humoral immune surveys drawn posttransplant, 47 (70%) had IgG levels less than 600 mg/dl (normal 717-1410 mg/dl), of which 25 (37%) had IgG levels less than 400 mg/dl ("lowest IgG group") and 22 (33%) had IgG levels between 400 and 600 mg/dl ("moderately low IgG group"). A total of 20 patients (30%) had IgG levels of more than 600 mg/dl ("normal IgG group"). Infections that were significantly more common in the lowest IgG group, and more common in the moderately low IgG group than the normal IgG group, included: number of pneumonias (P=0.0006), bacteremias (P=0.02), total bacterial infections (P=0.002), tissue-invasive cytomegalovirus (P=0.01), invasive aspergillosis (P=0.001), total fungal infections (P=0.001), and total infections (P=0.006). Median hospital days per posttransplant year was significantly different in the three groups (11.0 vs. 7.4 vs. 2.8 days, P=0.0003.) Invasive aspergillosis occurred in 44% of the lowest IgG group, 9% of the moderately low IgG group, and 0% of the normal IgG group (P<0.001). Survival was poorest in the lowest IgG group and intermediate in the moderately low IgG group. IgG subclass deficiencies occurred in a variety of patterns. Hypogammaglobulinemic patients lacked protective responses to Pneumococcus in 14/47 (30%), diphtheria in 15%, and tetanus in 19%. In a group of 48 patients screened pretransplant, 90% had normal immunoglobulin levels. CONCLUSIONS: Hypogammaglobulinemia in lung transplant recipients is more common than has been previously recognized. An IgG level of less than 400 mg/dl identifies a group at extremely high risk of bacterial and fungal infections, tissue-invasive cytomegalovirus, and poorer survival. Immunoglobulin monitoring may offer an opportunity for intensive surveillance, tapering of immunosuppression, and preemptive therapy for infection.

The humoral immune response to influenza vaccination in lung transplant patients.

The purpose of this study was to evaluate the humoral immune response to influenza vaccination in lung transplant recipients. Antibody levels to the three viral antigens included in the 1999-2000 trivalent influenza vaccine (A/Sydney/5/97-like (H3N2), A/Beijing262/95-like (H1N1), and B/Yamanashi/16/ 98) were measured before and 4 weeks postvaccination in 43 lung transplant recipients and 21 healthy adult controls. The ability to develop protective antibody levels, a serological response, and the magnitude of change in levels were assessed. The humoral immune response to influenza vaccination was significantly lower in the transplant group for all three viral antigens. To A/Sydney, 95% of the control group and 40% of the transplant group developed protective levels (p=0.0009); to A/Beijing, 71% of the control group and 30% of the transplant group developed protective levels (p=0.004); and to B/Yamanashi, 48% of the control group and 19% of the transplant group developed protective levels (p=0.02). Those receiving cyclosporine had lower antibody responses when compared to those receiving tacrolimus (r=-0.3056, p=0.0463). The humoral immune response to influenza vaccination in lung transplant recipients is poor. Lung transplant recipients receiving cyclosporine may have a lower antibody response than those receiving tacrolimus. Alternative prevention strategies may be needed.

Progressive portopulmonary hypertension after liver transplantation treated with epoprostenol.

Portopulmonary hypertension (PPHTN) is an uncommon complication of advanced liver disease. Epoprostenol has been effective in the treatment of PPHTN and has been used as a bridge to orthotopic liver transplantation (OLT). The role of OLT in the reversal of PPHTN is unclear. We report a case of severe PPHTN (mean pulmonary artery pressure of 45 mm Hg) that progressed after OLT. Acute dosing with epoprostenol improved the pulmonary vascular resistance by 55% and the cardiac index by 134%. Hemodynamic and symptomatic improvements were maintained after 18 months of long-term treatment with epoprostenol. This is the first reported case of a successful favorable outcome after treatment for progressive PPHTN after OLT. Our case report complements previous reports by highlighting the potential effective use of epoprostenol as a definitive treatment for PPHTN.

Exercise hemodynamic findings in patients with exertional dyspnea.

To determine whether upright bicycle exercise could provide useful information about disabling exertional dyspnea in the absence of severe abnormalities (as shown by traditional testing methods), we evaluated 13 such patients. There were 3 men and 10 women with a mean age of 49+/-15 (SD) years. We used pulmonary artery catheterization at rest and during upright bicycle exercise to evaluate these patients. All patients had normal left ventricular function except for 1, who had an ejection fraction of 45%. The mean duration to peak exercise was 9+/-6 minutes. Normal systolic pulmonary artery pressure was defined as 25+/-5 mmHg. Four patients had normal systolic pulmonary pressure, and 9 exhibited pulmonary hypertension with exercise. In those 9, the mean mixed pulmonary venous oxygen saturation at rest was 61%+/-9% and fell to 32%+/-9% at peak exercise. Six of the 9 patients also had some degree of resting pulmonary hypertension that worsened with exercise: their mean pulmonary artery systolic pressure at rest was 47+/-14 mmHg and rose to 75+/-25 mmHg at peak exertion (P = 0.01). The other 3 patients showed no pulmonary hypertension at rest; their mean pulmonary artery systolic pressure was 27+/-6 mmHg. However, this level rose to 53+/-4 mmHg at peak exertion (P = 0.04). In this pilot study of patients with dyspnea, 9 of 13 (69%) displayed marked pulmonary hypertension with exercise. The resting hemodynamic levels were normal in 3 (33%) of those with exercise pulmonary hypertension. We conclude that hemodynamic data from bicycle exercise tests can provide additional information regarding the mechanisms of exertional dyspnea.

Continuous intravenous epoprostenol for pulmonary hypertension due to the scleroderma spectrum of disease. A randomized, controlled trial.

BACKGROUND: Pulmonary hypertension is a progressive and often fatal complication of the scleroderma spectrum of disease for which no treatment has been proven effective in a randomized trial. OBJECTIVE: To determine the effect of epoprostenol on pulmonary hypertension secondary to the scleroderma spectrum of disease. DESIGN: Randomized, open-label, controlled trial. SETTING: 17 pulmonary hypertension referral centers. PATIENTS: 111 patients with moderate to severe pulmonary hypertension. INTERVENTION: Epoprostenol plus conventional therapy or conventional therapy alone. MEASUREMENTS: The primary outcome measure was exercise capacity. Other measures were cardiopulmonary hemodynamics, signs and symptoms of pulmonary hypertension and scleroderma, and survival. RESULTS: Exercise capacity improved with epoprostenol (median distance walked in 6 minutes, 316 m at 12 weeks compared with 270 m at baseline) but decreased with conventional therapy (192 m at 12 weeks compared with 240 m at baseline). The difference between treatment groups in the median distance walked at week 12 was 108 m (95% CI, 55.2 m to 180.0 m) (P < 0.001). Hemodynamics improved at 12 weeks with epoprostenol. The changes in mean pulmonary artery pressure for the epoprostenol and conventional therapy groups were -5.0 and 0.9 mm Hg, respectively (difference, -6.0 mm Hg [CI, -9.0 to -3.0 mm Hg), and the mean changes in pulmonary vascular resistance were -4.6 and 0.9 mm Hg/L per minute, respectively (difference, -5.5 mm Hg/L per minute [CI, -7.3 to -3.7 mm Hg/L per minute). Twenty-one patients treated with epoprostenol and no patients receiving conventional therapy showed improved New York Heart Association functional class. Borg Dyspnea Scores and Dyspnea-Fatigue Ratings improved in the epoprostenol group. Trends toward greater improvement in severity of the Raynaud phenomenon and fewer new digital ulcers were seen in the epoprostenol group. Four patients in the epoprostenol group and five in the conventional therapy group died (P value not significant). Side effects of epoprostenol therapy included jaw pain, nausea, and anorexia. Adverse events related to the epoprostenol delivery system included sepsis, cellulitis, hemorrhage, and pneumothorax (4% incidence for each condition). CONCLUSIONS: Continuous epoprostenol therapy improves exercise capacity and cardiopulmonary hemodynamics in patients with pulmonary hypertension due to the scleroderma spectrum of disease.

Epoprostenol for treatment of pulmonary hypertension in patients with systemic lupus erythematosus.

OBJECTIVE: Pulmonary hypertension with pathological changes similar to those observed in primary pulmonary hypertension occurs in patients with systemic lupus erythematosus (SLE). The efficacy of chronic epoprostenol therapy in SLE has not been well described. The objective of this paper is to describe our experience with long-term epoprostenol therapy in patients with pulmonary hypertension associated with SLE. DESIGN: Case series of six patients with SLE and associated pulmonary hypertension receiving chronic treatment with epoprostenol. RESULTS: All 6 patients had severe pulmonary hypertension. Mean pulmonary artery pressure (mPAP) was 57 +/- 9 mm Hg (mean +/- SD), and pulmonary vascular resistance was 14 +/- 7 units before beginning therapy with epoprostenol. In 4 patients who underwent repeat hemodynamic evaluation (9 to 16 months after starting epoprostenol), mean pulmonary artery pressure decreased by 38 +/- 21% and pulmonary vascular resistance by 58 +/- 12%. Clinically, all patients improved from New York Heart Association class III or IV to class I or II. Doses of epoprostenol ranged from 4 to 46 ng/kg/min, and the longest duration of therapy has been 2.5 years. Side effects from epoprostenol have not differed from those seen in patients with primary pulmonary hypertension, and except for one patient, there has been no exacerbation of SLE. CONCLUSION: Epoprostenol was effective for the treatment of pulmonary hypertension in this small group of patients with SLE. Further evaluation of epoprostenol therapy for patients with SLE and other diseases associated with pulmonary hypertension is warranted.

Increased alveolar macrophage nuclear factor-kappa B activation and macrophage inhibitory protein-1alpha levels in lung transplant patients.

BACKGROUND: Lung transplantation is increasingly used as the treatment for many end-stage pulmonary diseases. A major cause of morbidity and mortality in patients who undergo lung transplantation is rejection of the allograft. Proinflammatory macrophage-derived cytokines may sustain and/or enhance the immunological response to lung allograft antigens. Nuclear factor-kappa B (NF-kappaB) is a transcription factor that regulates the production of many of these cytokines and growth factors in alveolar macrophages (AMs). The aim of our study was to evaluate the activation of NF-kappaB in AMs and the levels of one of the proinflammatory cytokines whose production it controls, macrophage inhibitory protein-1alpha (MIP-1alpha), in AMs from transplanted lungs compared to those from healthy controls. METHODS: Twenty-eight (28) transplant recipients were included in the study. NFkappaB activation was evaluated by electrophoretic mobility shift assay of whole cell extracts and by immunohistochemical analysis on cytospin preparations. Concentrated bronchoalveolar lavage fluid was analyzed by enzyme-linked immunosorbent assay for MIP-1alpha levels. RESULTS: NF-kappaB was activated in alveolar macrophages from transplant patients as compared to healthy controls. MIP-1alpha levels in epithelial-lining fluid were elevated in transplant patients as compared to healthy controls. Increased MIP-1alpha levels correlated with viral infections in the transplant patients. Neither finding was found to correlate with acute rejection by transbronchial biopsy. CONCLUSIONS: These results demonstrate that NF-kappaB activation and MIP-1alpha levels are increased in transplanted lungs and may play a role in the inflammatory cytokine cascade that leads to the long-term tissue damage and allograft rejection in these patients.

A prospective evaluation of esophageal testing and a double-blind, randomized study of omeprazole in a diagnostic and therapeutic algorithm for chronic cough.

OBJECTIVE: Recent studies suggest an association between chronic cough and gastroesophageal reflux. Our study aims were 1) to define the prevalence of acid reflux induced cough in the general community, 2) to examine the ability of esophageal testing to identify gastroesophageal reflux related cough, and 3) to assess the utility of omeprazole in a chronic cough algorithm. METHODS: Patients with chronic cough of unknown etiology, who were mostly from the community, were evaluated. Subjects underwent a chest x-ray, methacholine challenge test, and empiric trial of postnasal drip therapy, and completed daily cough symptom diaries subjectively evaluating cough frequency and severity on a graded scale of 0-4 (combined maximum 8). After excluding other causes of cough, the remaining patients underwent esophageal and pH testing. Those testing positive were randomized to omeprazole 40 mg b.i.d. or placebo for 12 weeks. Follow-up was 1 yr. RESULTS: A total of 71 patients were screened; 48 were excluded. Twenty-three patients were evaluated for gastroesophageal reflux disease; six (26%) were eventually determined to have an acid-related cough. Of these patients, 17 had a positive pH test, six (35%) of whom showed a striking improvement or resolution of their cough during omeprazole treatment which was sustained for up to 1 yr. Six had a negative pH test, none of whom responded to omeprazole therapy. No significant differences were seen between responders (n = 6) and nonresponders (n = 11) for demographic factors, baseline symptom frequency and duration, or physiological parameters (motility/pH). CONCLUSIONS: Acid-related chronic cough was present in 26% (six of 23) of patients evaluated for gastroesophageal reflux disease. Esophageal testing does not reliably identify patients with acid induced chronic cough responsive to proton pump inhibitor therapy. We suggest that the best diagnostic and therapeutic approach, after excluding asthma and postnasal drip syndrome, is empiric treatment for 2 wk with a high dose proton pump inhibitor.

Intravenous azithromycin-induced ototoxicity.

Intravenous azithromycin is increasingly administered for treatment of hospitalized patients with community-acquired pneumonia. Macrolide antibiotics cause ototoxicity, which occurs most frequently when high serum concentrations are achieved. Current dosing guidelines for intravenous azithromycin can result in much higher serum concentrations than is seen with oral administration. We describe a 47-year-old woman who developed complete deafness after receiving 8 days of intravenous azithromycin.

Spontaneous resolution of rhodococcal pulmonary infection in a liver transplant recipient.

Pulmonary infection by Rhodococcus equi is characterized by indolent infection in an immunocompromised host with a propensity to form cavitary lesions. Mortality can be greater than 50%; treatment involves prolonged therapy with multiple antibiotics and, occasionally, surgical resection. Recurrence is common. We report a case of a liver transplant patient with a pulmonary nodule caused by R equi; the nodule followed a benign clinical course and resolved spontaneously. This case illustrates that the spectrum of disease caused by R equi is not fully appreciated and that significant pitfalls complicate the diagnosis and management of infection by this unusual and probably underrecognized pathogen.

Transient subversion of CD40 ligand function diminishes immune responses to adenovirus vectors in mouse liver and lung tissues.

First-generation adenovirus vectors will have limited application in gene therapy for chronic diseases because of destructive host immune responses. Important immune effectors include CD8+ T cells, which mediate target cell destruction and ablate transgene expression, and B cells, which produce neutralizing antibodies that block effective readministration of vector. Previous studies indicated that activation of CD4+ T cells by virus capsid proteins is necessary for full realization of effector function of CD8+ T cells and B cells. In this paper, we present a strategy for preventing CD4+ T-cell activation by an adenovirus vector delivered to mouse liver and lung tissues which is based on interfering with T-cell priming via CD40 ligand-CD40 interactions. Adenovirus transgene expression was stabilized in mice genetically deficient in CD40 ligand (CD40L), and neutralizing antibody to adenovirus did not develop, allowing efficient readministration of vector. A transient blockade of T-cell activation with an antibody to CD40L infused into the animal at the time of adenovirus vector-mediated gene transfer led to stabilization of transgene expression and diminished production of neutralizing antibody, allowing readministration of vector. In vitro T-cell assays suggested that a block in the primary activation of CD4+ T cells was responsible for the lack of B-cell- and cytotoxic-T-cell-dependent responses. This suggests a strategy for improving the potential of adenovirus vectors based on administration of an antibody to CD40L at the time of vector administration.