D.A. van Kessel

Impaired pneumococcal antibody response in bronchiectasis of unknown aetiology

As a defective anti-polysaccharide response can exist in the absence of an immunoglobulin deficiency, a series of 26 patients with bronchiectasis of unknown aetiology was vaccinated with a 23-valent pneumococcal polysaccharide vaccine. All patients suffered from recurrent respiratory tract infections. When measuring total antibody levels to pneumococcal serotypes 3, 4 and 9, a normal polysaccharide antibody response was found in 22 patients. However, only 11 of these subjects showed a normal pneumococcal antibody response within the IgA and/or IgG2 subclass, and thus could be classified as true responders, while 15 patients did not respond in either the IgA class or in the IgG2 subclass. When analysing differences between the responder (n = 11) and nonresponder (n = 15) groups, the latter demonstrated higher frequencies of respiratory tract infections and more severe lung pathology, as revealed by the presence of more bronchi visualised in the peripheral third of the lung by high-resolution computed tomography scanning. Moreover, nonresponders needed extensive lung surgery more often in order to control their disease (number of resected segments eight versus five). In conclusion, an important fraction of patients presenting with idiopathic bronchiectasis is associated with a selective anti-polysaccharide response deficiency and this subgroup appears to represent a more severe clinical phenotype. Therefore, it can be regarded as a separate clinical entity with possible therapeutic targets. In order to identify IgA and IgG2 anti-polysaccharide nonresponders, all patients presenting with bronchiectasis of unkown aetiology should be immunised with a pneumococcal polysaccharide vaccine, and IgA and IgG2 isotype responses should be evaluated as well as the total antibody response.

Diabetes before and after lung transplantation in patients with cystic fibrosis and other lung diseases.

Diabet. Med. 29, e159–e162 (2012)

A Promoter Polymorphism in the CD59 Complement Regulatory Protein Gene in Donor Lungs Correlates With a Higher Risk for Chronic Rejection After Lung Transplantation

Complement activation leads primarily to membrane attack complex formation and subsequent target cell lysis. Protection against self‐damage is regulated by complement regulatory proteins, including CD46, CD55, and CD59. Within their promoter regions, single‐nucleotide polymorphisms (SNPs) are present that could influence transcription. We analyzed these SNPs and investigated their influence on protein expression levels. A single SNP configuration in the promoter region of CD59 was found correlating with lower CD59 expression on lung endothelial cells (p = 0.016) and monocytes (p = 0.013). Lung endothelial cells with this SNP configuration secreted more profibrotic cytokine IL‐6 (p = 0.047) and fibroblast growth factor β (p = 0.036) on exposure to sublytic complement activation than cells with the opposing configuration, whereas monocytes were more susceptible to antibody‐mediated complement lysis (p < 0.0001). Analysis of 137 lung transplant donors indicated that this CD59 SNP configuration correlates with impaired long‐term survival (p = 0.094) and a significantly higher incidence of bronchiolitis obliterans syndrome (p = 0.046) in the recipient. These findings support a role for complement in the pathogenesis of this posttransplant complication and are the first to show a deleterious association of a donor CD59 promoter polymorphism in lung transplantation.

Serum thymus and activation regulated chemokine levels post‐lung transplantation as a predictor for the bronchiolitis obliterans syndrome

The main reason for mortality after lung transplantation is the bronchiolitis obliterans syndrome (BOS), which represents chronic rejection. As soluble CD30, which is produced mainly by activated T helper 2 (Th2) cells, was shown to be related to development of BOS, we aimed to investigate the relation between development of BOS and Th2 chemoattractant thymus and activation regulated chemokine (TARC/CCL17). In 54 patients we measured serum TARC levels prior to transplantation by enzyme‐linked immunosorbent assay, and in 44 of these patients sera were analysed at months 1, 2 and 3 after lung transplantation. In addition, longitudinal measurements were performed in sera from eight healthy controls and 14 patients, the latter taken over a period of 2 years post‐transplantation from seven patients developing BOS plus seven clinically matched BOS‐free patients. Median serum TARC levels post‐transplantation of patients who developed BOS were significantly lower than those of the matched BOS‐free patients (P = 0·05). A receiver operating characteristics analysis (area under the curve 0·77), together with a Kaplan–Meyer analysis, showed that serum TARC levels below 325 pg/ml in the first month post‐transplantation can predict development of BOS post‐transplantation (P = 0·001). In contrast, pretransplant serum TARC levels were not significantly different between patients developing BOS, BOS‐free patients or healthy controls. In conclusion, pretransplantation serum TARC levels do not predict the development of BOS post‐transplantation, but measurement of the serum TARC levels in the first month directly after transplantation can provide us with a tool to identify the group at risk of developing BOS.

Clinical and immunological evaluation of patients with mild IgG1 deficiency

Serum IgG subclass concentrations were determined in patients visiting, the pulmonology out‐patient clinic with chronic respiratory tract problems. A total of 24 patients with a serum IgG1 concentration < 4.9 g/l (i.e. below the reference range) and normal values for IgG2, IgM and IgA were included. Patients with a selective IgG1 deficiency were vaccinated with a 23‐valent pneumococcal polysaccharide vaccine. There were nine patients with a poor antibody response to pneumococcal capsular polysaccharide antigens. Responsiveness to protein antigens was intact in all patients. Patients with pneumonia showed a significantly lower anti‐polysaccharide response in the IgG2 subclass than patients without pneumonia. Patients with recurrent sinusitis showed a significantly lower response in the IgA isotype after vaccination with pneumococcal polysaccharide vaccine compared with non‐sinusitis patients. It can be concluded that patients with recurrent sinopulmonary infections and a mild IgG1 subclass deficiency have an impaired IgG1 anti‐polysaccharide response, which can extend to decreased IgG2 and IgA anti‐polysaccharide responses.

Anti-ETAR and anti-AT1R autoantibodies are elevated in patients with endstage cystic fibrosis

Autoantibodies against endothelin-1 type A receptor (ETAR) are present in systemic sclerosis complicated by lung fibrosis and pulmonary hypertension. As increased serum levels and local overproduction of endothelin-1 in the airways are reported in cystic fibrosis (CF) patients, we reasoned that anti-ETAR antibodies could be prevalent in endstage CF patients prior to lung transplantation (LTx). Also, ETAR autoantibodies are frequently associated with autoantibodies against the angiotensin II type 1 receptor (AT1R). We analyzed the presence of anti-ETAR and anti-AT1R autoantibodies in 43 LTx patients (chronic obstructive pulmonary disease (COPD), n=20; CF, n=13; interstitial lung disease (ILD), n=1). We observed overall higher anti-ETAR and anti-AT1R autoantibody titers in sera taken prior to LTx in the CF patient group as compared to COPD. No difference was found in autoantibody levels between patients with CF versus ILD. In sera taken post-LTx we found the same difference in anti-ETAR and anti-AT1R autoantibody titers between patients with CF versus COPD. No difference was found in antibody titers between sera taken prior to or 6 months after LTx. There was no association between autoantibody levels and other relevant demographic parameters, and we found no association between autoantibody titers and the development of the bronchiolitis obliterans syndrome. Both autoantibody titers were strongly correlated. We hypothesize that due to prolonged exposure to bacterial infection, increased levels of AT1R and ETAR result in a deregulated immune response causing autoantibody formation. Further research is expedient to elucidate the occurrence of autoantibodies against ETAR and AT1R and their role in disease progression.

Mannose-binding lectin deficiency linked to cytomegalovirus (CMV) reactivation and survival in lung transplantation.

Despite the use of immunosuppressives mainly influencing T and B cell responses, the prevalence of the bronchiolitis obliterans syndrome (BOS) after lung transplantation is high. Mannose‐binding lectin (MBL) is a pattern recognition molecule of complement and an important component of the innate immunity. MBL is associated with rejection, infection and survival in other solid organ transplantations. In this study the relation between functional MBL levels and cytomegalovirus (CMV) reactivations and the development of BOS and survival after lung transplantation was investigated. MBL levels were measured in 85 patients before and in 57 of these patients after lung transplantation. The relation of MBL on survival, CMV reactivation and the development of BOS were investigated with Kaplan–Meier (log‐rank) survival analysis. MBL levels decreased on average by 20% (P < 0·001) after transplantation and eventually returned to pretransplant levels. Fourteen of the 85 patients had deficient pretransplant MBL levels and these patients had a tendency towards a better survival compared to those with normal MBL levels (P = 0·08). Although no correlation was found between MBL deficiency and the development of BOS, more CMV reactivations occurred in recipients with deficient versus normal levels of MBL (P = 0·03). Our results suggest that MBL deficiency is associated with CMV reactivations and a longer overall survival, but not with the development of BOS.

Effective Prolonged Therapy with Voriconazole in a Lung Transplant Recipient with Spondylodiscitis Induced by Scedosporium apiospermum

Scedosporium/Pseudallescheria species are frequently seen in cystic fibrosis patients. However, disseminated forms after lung transplantation in these patients are rarely seen, but often with poor outcome. In this case report we describe a lung transplant recipient with cystic fibrosis who developed a spondylodiscitis that was caused by Scedosporium apiospermum. The patient was treated with anti-fungal treatment by voriconazole for over three years with a clinical good response and without the need for surgical intervention. To our opinion this is the first anti-fungal treated case of invasive disease caused by Scedosporium/Pseudallescheria in a cystic fibrosis (CF) patient who underwent lung transplantation that survived.

Response to pneumococcal vaccination in mannose-binding lectin-deficient adults with recurrent respiratory tract infections.

Mannose‐binding lectin (MBL)‐deficiency is associated with an increased susceptibility to pneumococcal infections and other forms of disease. Pneumococcal vaccination is recommended in MBL‐deficient patients with recurrent respiratory tract infections (RRTI). The response to pneumococcal vaccination in MBL‐deficient individuals has not yet been studied in detail. An impaired response to pneumococcal polysaccharides in MBL‐deficient patients might explain the association between MBL deficiency and pneumococcal infections. This study investigates the antibody response to pneumococcal vaccination in MBL‐deficient adult patients with RRTI. Furthermore, we investigated whether there was a difference in clinical presentation between MBL‐deficient and ‐sufficient patients with RRTI. Eighteen MBL‐deficient and 63 MBL‐sufficient adult patients with RRTI were all vaccinated with the 23‐valent pneumococcal polysaccharide vaccine and antibodies to 14 pneumococcal serotypes were measured on a Luminex platform. There were no differences observed in the response to pneumococcal vaccination between MBL‐sufficient and ‐deficient patients. Forty‐three MBL‐sufficient patients could be classified as responders to pneumococcal vaccination and 20 as low responders, compared to 15 responders and three low responders in the MBL‐deficient patients. We found no clear difference in clinical, radiological, lung function and medication parameters between MBL‐sufficient and ‐deficient patients. In conclusion, our study suggests that MBL‐deficient adults with RRTI have a response to a pneumococcal capsular polysaccharide vaccine comparable with MBL‐sufficient patients. Moreover, we did not find a clear clinical role of MBL deficiency in adults with RRTI. As MBL deficiency is associated with an increased susceptibility to pneumococcal infections, pneumococcal vaccination might be protective in MBL‐deficient patients with RRTI.

Lung transplantation affects expression of the chemokine receptor type 4 on specific T cell subsets

Alloreactive T cells that infiltrate the graft after lung transplantation (LTx) play a role in chronic rejection. Chemokines such as thymus and activation‐regulated chemokine (TARC), macrophage‐derived chemokine (MDC) and monocyte chemotactic protein‐1 (MCP‐1) are produced locally in the lung and attract T cells via chemokine receptor 4 (CCR4). In a TARC gradient, cells expressing CCR4++ migrate more efficiently than CCR4+‐expressing cells. In this study, we compared the CCR4 expression of T cells in blood from 20 lung transplant recipients to healthy controls. We then examined whether CCR4 expression is associated with the occurrence of chronic rejection. The CCR4++ expression was decreased on CD4 T cells from LTx patients (P < 0·0001) when compared to healthy controls. The analysis of CD4 T cell subsets showed that this decrease was present on central memory, effector memory and terminally differentiated T cells (P = 0·0007, P < 0·0001 and P = 0·05, respectively), while a trend was found for naive CD4 T cells (P = 0·06). Also, the expression of CCR4+ on regulatory T cells (Tregs) was decreased in LTx patients when compared to healthy controls (P = 0·02). Interestingly, the CCR4++ expression on CD4 effector memory T cells was decreased in patients developing chronic rejection sometimes more than a year before the clinical diagnosis when compared to patients who did not (P = 0·04). The analysis of CD8 T cell subsets only showed the CCR4+ expression to be increased significantly on effector memory and terminally differentiated CD8 T cells (P = 0·02, P = 0·03, respectively) in LTx patients, but no relation was found in chronic rejection. In conclusion, the expression of CCR4 on T cell subsets was altered after LTx and appears to be related to chronic rejection.