Aaron P. Milstone

Obstructive Sleep Apnea Is Common in Idiopathic Pulmonary Fibrosis

BACKGROUND From 1984 to 2006, studies of sleep in patients with interstitial lung disease revealed disturbed sleep, frequent nocturnal desaturations, nocturnal cough, and obstructive sleep apnea (OSA). Our goal was to analyze OSA in an outpatient population of stable patients with idiopathic pulmonary fibrosis (IPF). METHODS Patients with IPF who had been followed up in the Vanderbilt Pulmonary Clinic were asked to participate. All patients were given a diagnosis of IPF by the 2000 American Thoracic Society consensus statement criteria. Subjects completed an Epworth sleepiness scale (ESS) questionnaire and a sleep apnea scale of sleep disorders questionnaire (SA-SDQ) before undergoing nocturnal polysomnography (NPSG). OSA was defined as an apnea-hypopnea index (AHI) of > 5 events per hour. RESULTS Fifty subjects enrolled and completed a NPSG. The mean age was 64.9 years, and the mean BMI was 32.3. OSA was diagnosed in 88% of subjects. Ten subjects (20%) had mild OSA (AHI, 5 to 15 events per hour), and 34 subjects (68%) had moderate-to-severe OSA (AHI, > 15 events per hour). Only 6 subjects (12%) had a normal AHI. One patient was asymptomatic as determined by ESS and SA-SDQ, but had an AHI of 24 events per hour. The sensitivity of the ESS was 75% with a specificity of 15%, whereas the SA-SDQ had a sensitivity of 88% with a specificity of 50%. BMI did not correlate strongly with AHI (r = 0.30; p = 0.05). CONCLUSIONS OSA is prevalent in patients with IPF and may be underrecognized by primary care providers and specialists. Neither ESS nor SA-SDQ alone or in combination was a strong screening tool. Given the high prevalence found in our sample, formal sleep evaluation and polysomnography should be considered in patients with IPF.

Clinical features and outcomes of paramyxoviral infection in lung transplant recipients treated with ribavirin

BACKGROUND Paramyxoviral infections are reported in 6% to 21% of lung transplant recipients. Aerosolized ribavirin is used to treat paramyoxviral infections, but data on outcomes of this treatment in lung transplant patients are limited. METHODS Lung recipients treated with aerosolized ribavirin from 1992 through 2000 for pulmonary respiratory syncytial virus (RSV) or parainfluenza virus (PIV) infection were assessed for the following variables: age; gender; underlying diagnosis; time from transplantation; duration of illness; clinical symptoms; and change from baseline FEV(1) (forced expiratory volume in 1 second). Outcomes included FEV(1) values at 30 and 90 days, need for intubation, development of acute rejection or obliterative bronchiolitis (OB) in the year after treatment; and 90-day and overall mortality. RESULTS Fifteen patients received ribavirin for a median of 5 days (range 3 to 7) for 17 episodes of RSV (n = 12) or PIV (n = 5) infection. The clinical presentations of RSV and PIV infection were similar. Infection occurred a median of 520 days (range 7 to 1700) after transplantation. Three episodes required intubation; 2 episodes were fatal accounting for a 90-day mortality per episode of 12%. The FEV(1) at presentation declined by 25% (range 4% to 44%) from baseline. In 3 patients the FEV(1) did not return to baseline by 90 days or thereafter. All 3 patients had underlying pulmonary fibrosis (IPF) vs no IPF in 0 of 9 evaluable patients who recovered (p = 0.009). There was no correlation between response to ribavirin and subsequent development of OB. CONCLUSIONS About 33% of lung transplant patients with lower respiratory tract paramyxoviral infections who were treated with inhaled ribavirin died or did not return to baseline FEV(1). This effect was acute and not associated with later complications, including OB. Underlying IPF may be a risk factor for failure to return to baseline. Larger, prospective, multicenter studies are required to confirm these findings.

Plasma Cytokines and Chemokines in Primary Graft Dysfunction Post-Lung Transplantation

Primary graft dysfunction (PGD) after lung transplantation causes significant morbidity and mortality. We aimed to determine the role of cytokines and chemokines in PGD. This is a multicenter case–control study of PGD in humans. A Luminex analysis was performed to determine plasma levels of 25 chemokines and cytokines before and at 6, 24, 48 and 72 h following allograft reperfusion in 25 cases (grade 3 PGD) and 25 controls (grade 0 PGD). Biomarker profiles were evaluated using a multivariable logistic regression and generalized estimating equations. PGD cases had higher levels of monocyte chemotactic protein‐1 (MCP‐1)/chemokine CC motif ligand 2 (CCL2) and interferon (IFN)‐inducible protein (IP‐10)/chemokine CXC motif ligand 10 (CXCL10) (both p < 0.05), suggesting recruitment of monocytes and effector T cells in PGD. In addition, PGD cases had lower levels of interleukin (IL‐13) (p = 0.05) and higher levels of IL‐2R (p = 0.05). Proinflammatory cytokines, including tumor necrosis factor (TNF)‐α, and IFN‐γ decreased to very low levels after transplant in both PGD cases and controls, exhibiting no differences between the two groups. These findings were independent of clinical variables including diagnosis in multivariable analyses, but may be affected by cardiopulmonary bypass. Profound injury in clinical PGD is distinguished by the upregulation of selected chemokine pathways, which may useful for the prediction or early detection of PGD if confirmed in future studies.

Plasma Intercellular Adhesion Molecule-1 and von Willebrand Factor in Primary Graft Dysfunction After Lung Transplantation

Primary graft dysfunction (PGD), a form of acute lung injury occurring within 72 h following lung transplantation, is characterized by pulmonary edema and diffuse alveolar damage. We hypothesized that higher concentrations of intercellular adhesion molecule‐1 (ICAM‐1) and von Willebrand factor (vWF) would be associated with the occurrence of PGD. A total of 128 lung transplant recipients among 7 lung transplant centers were enrolled in a multicenter, prospective, cohort study. Blood specimens were collected preoperatively and at 6, 24, 48 and 72 h following lung transplantation. The primary outcome was Grade 3 PGD at 72 h after transplant. Logistic regression and generalized estimating equations (GEE) were used to analyze plasma ICAM‐1 and vWF. At each postoperative timepoint, mean plasma ICAM‐1 concentrations were higher for patients with PGD versus no PGD. The GEE contrast estimate for the association of plasma ICAM‐1 with PGD was 107.5 ng/mL (95% CI 38.7, 176.3), p = 0.002. In the multivariate analyses, this finding was independent of all clinical variables except pulmonary artery pressures prior to transplant. There was no association between plasma vWF levels and PGD. We conclude that higher levels of plasma ICAM‐1 are associated with PGD following lung transplantation.

Polyomavirus simian virus 40 infection associated with nephropathy in a lung-transplant recipient.

Background. Between 1955 and 1963, millions of individuals worldwide received vaccines contaminated with polyomavirus simian virus (SV)40. Recent data suggest that some individuals may develop renal dysfunction related to SV40 infection, including individuals too young to have received contaminated vaccines. Case Report and Results. Three years after bilateral lung transplantation, a 32-year-old man with cystic fibrosis developed nephrotic syndrome and progressed to end-stage renal failure over 1.5 years. He was shown to have nephropathy caused by SV40. The diagnosis was documented by detecting and confirming sequences of SV40 (but not BK or JC virus) in his kidney biopsy and urine by polymerase chain reaction, Southern blot, and DNA sequencing. Positive immunohistochemistry for SV40 was found in his kidney, and neutralizing antibodies for SV40 were detected in his serum, before and after the onset of renal dysfunction. A source for the virus was not determined. His household contacts did not have serologic or molecular evidence of SV40 infection. No serum or tissue samples were available from his 27-year-old donor. Discussion. This report shows that SV40 is circulating in the community and can cause nephropathy in transplant patients.

Bronchial Secretory Immunoglobulin A Deficiency Correlates With Airway Inflammation and Progression of Chronic Obstructive Pulmonary Disease

RATIONALE Although airway inflammation can persist for years after smoking cessation in patients with chronic obstructive pulmonary disease (COPD), the mechanisms of persistent inflammation are largely unknown. OBJECTIVES We investigated relationships between bronchial epithelial remodeling, polymeric immunoglobulin receptor (pIgR) expression, secretory IgA (SIgA), airway inflammation, and mural remodeling in COPD. METHODS Lung tissue specimens and bronchoalveolar lavage were obtained from lifetime nonsmokers and former smokers with or without COPD. Epithelial structural changes were quantified by morphometric analysis. Expression of pIgR was determined by immunostaining and real-time polymerase chain reaction. Immunohistochemistry was performed for IgA, CD4 and CD8 lymphocytes, and cytomegalovirus and Epstein-Barr virus antigens. Total IgA and SIgA were measured by ELISA and IgA transcytosis was studied using cultured human bronchial epithelial cells. MEASUREMENTS AND MAIN RESULTS Areas of bronchial mucosa covered by normal pseudostratified ciliated epithelium were characterized by pIgR expression with SIgA present on the mucosal surface. In contrast, areas of bronchial epithelial remodeling had reduced pIgR expression, localized SIgA deficiency, and increased CD4(+) and CD8(+) lymphocyte infiltration. In small airways (<2 mm), these changes were associated with presence of herpesvirus antigens, airway wall remodeling, and airflow limitation in patients with COPD. Patients with COPD had reduced SIgA in bronchoalveolar lavage. Air-liquid interface epithelial cell cultures revealed that complete epithelial differentiation was required for normal pIgR expression and IgA transcytosis. CONCLUSIONS Our findings indicate that epithelial structural abnormalities lead to localized SIgA deficiency in COPD airways. Impaired mucosal immunity may contribute to persistent airway inflammation and progressive airway remodeling in COPD.

Acute Humoral Rejection of Human Lung Allografts and Elevation of C4d in Bronchoalveolar Lavage Fluid

Antibody‐mediated rejection is well established for renal allografts but remains controversial for lung allografts. Cardinal features of antibody‐mediated rejection in renal allografts include antibodies to donor human leukocyte antigen (HLA) and evidence for antibody action, such as complement activation demonstrated by C4d deposition. We report a lung allograft recipient with circulating antibodies to donor HLA who failed treatment for acute cellular rejection but responded to therapy for humoral rejection. To address the second criteria for antibody‐mediated rejection, we determined whether complement activation could be detected by measuring C4d in bronchoalveolar lavage fluid (BALF) by ELISA. Airway allergen challenge of asthmatics activates the complement pathway; therefore, we used BALF from asthmatics pre‐ and post‐allergen challenge to measure C4d. These controls demonstrated that ELISA could detect increases in C4d after allergen challenge. BALF from the index patient had elevated C4d concomitant with graft dysfunction and anti‐donor HLA in the absence of infection. Analysis of BALF from 25 additional lung allograft recipients showed that C4d concentrations >100 ng/mL were correlated with anti‐HLA antibodies (p = 0.006), but were also observed with infection and in asyptomatic patients. The findings support the occurrence of anti‐HLA‐mediated lung allograft rejection and suggest that C4d measurement in BALF may be useful in diagnosis.

A prospective longitudinal study of polyomavirus shedding in lung-transplant recipients.

BACKGROUND Polyomavirus infection causes renal dysfunction after kidney transplantation, but it has not been thoroughly investigated in nonrenal solid-organ transplantation. METHODS Fifty lung-transplant recipients provided prospective urine and blood samples over the course of 17 months. Samples were analyzed for BK virus (BKV), JC virus (JCV), and simian virus 40 (SV40) using conventional polymerase chain reaction (PCR), sequence analysis, and quantitative real-time PCR. RESULTS Thirty-one (62%) of 50 patients had polyomavirus detected in at least 1 urine specimen, including 16 (32%) for BKV, 12 (24%) for JCV, and 6 (12%) for SV40. Mean BKV loads (5.0 log(10) copies/mL) did not differ from those of JCV (5.7 log(10) copies/mL; P=.38), but SV40 loads (2.5 log(10) copies/mL) were lower than those of BKV (P=.006) and JCV (P=.002). Blood samples were negative. Infection with individual polyomaviruses or polyomavirus infection in aggregate was not associated with reduced creatinine clearance. Patients not shedding polyomavirus had better survival than patients shedding polyomavirus (P=.049). CONCLUSIONS Polyomaviruses BKV and JCV were commonly detected in urine from lung-transplant recipients. SV40 was found in 12% of patients but was shed at a lower frequency and with lower viral loads than the other viruses. Polyomavirus infection was not associated with renal dysfunction.

Association of progressive structural changes in the bronchial epithelium with subepithelial fibrous remodeling: a potential role for hypoxia.

In airway remodeling that occurs in association with chronic obstructive pulmonary disease (COPD), the relationship between the subepithelium and structural changes of the bronchial epithelium is not well defined. To investigate whether the subepithelium and epithelium undergo remodeling as an integrated unit, we performed morphological examination of 55 bronchial biopsy specimens obtained from explanted or resected lungs from tobacco smokers with COPD. Our results indicate that reticular basement membrane (RBM) thickness is increased and the subepithelial microvascular bed is reduced in association with progression from the normal epithelium to squamous metaplasia. Subsequent bronchial epithelial transformation to dysplasia is characterized by differential subepithelial remodeling with normalization of RBM thickness and subepithelial blood vessel density. Because fibrous remodeling of the subepithelium could limit delivery of nutrients and oxygen to the epithelium, we assessed expression of hypoxia-inducible factor-1α (HIF-1α) and carbonic anhydrase IX (CA IX) as markers of cellular hypoxia. The number of HIF-1α-positive epithelial cells increased with progression of epithelial structural changes, RBM thickness, and reduction in blood vessels in the subepithelium. These findings suggest that the HIF-1α pathway is activated in response to subepithelial remodeling and contributes to progressive premalignant epithelial lesions in the airways of tobacco smokers with chronic airway inflammation.

Polyomavirus Infection and Its Impact on Renal Function and Long-Term Outcomes after Lung Transplantation

Background. Polyomavirus infection causes nephropathy after kidney transplantation but has not been thoroughly investigated in nonrenal organ transplantation. Methods. Ninety lung transplant recipients were enrolled, and they provided urine samples for over 4.5 years. Samples were analyzed for BK virus (BKV), JC virus (JCV), and simian virus 40 (SV40) by conventional and quantitative real-time polymerase chain reaction. Results. Fifty-nine (66%) patients had polyomavirus detected at least once, including 38 patients (42%) for BKV, 25 patients (28%) for JCV, and six patients (7%) for SV40. Frequency of virus shedding in serial urine samples by patients positive at least once varied significantly among viruses: JCV, 64%; BKV, 48%; and SV40, 14%. Urinary viral loads for BKV (105.4 copies/mL) and JCV (106.0 copies/mL) were higher than for SV40 (102.5 copies/mL; P=0.001 and 0.0003, respectively). Polyomavirus infection was associated with a pretransplant diagnosis of chronic obstructive pulmonary disease (odds ratio 6.0; P=0.016) but was less common in patients with a history of acute rejection (odds ratio 0.28; P=0.016). SV40 infection was associated with sirolimus-based immunosuppression (P=0.037). Reduced survival was noted for patients with BKV infection (P=0.03). Patients with polyomavirus infection did not have worse renal function than those without infection, but in patients with BKV infection, creatinine clearances were lower at times when viral shedding was detected (P=0.038). Conclusions. BKV and JCV were commonly detected in the urine of lung transplant recipients; SV40 was found at low frequency. No definite impact of polyomavirus infection on renal function was documented. BKV infection was associated with poorer survival.