Interaction of panic and episodic breathlessness among patients with life-limiting diseases: a cross-sectional study.

BACKGROUND: Episodic breathlessness is often accompanied by panic. A vicious cycle of breathlessness-panic-breathlessness leads to emergencies with severe breathlessness and/or fear of dying. However, the interaction between episodic breathlessness and panic is poorly understood. Thus, the aim is a better understanding of the interaction between panic and episodic breathlessness to develop appropriate support for patients suffering from this symptom. METHODS: Patients suffering from episodic breathlessness due to life-limiting diseases answered questions on the characteristics of episodic breathlessness and panic-spectrum psychopathology, including underlying mechanisms. Using the Patient Health Questionnaire and the Structured Clinical Interview for DSM-IV Diagnoses (SCID), patients were screened for panic disorder. An open-ended question captured the patients' descriptions of panic during breathlessness episodes. RESULTS: Forty-six patients [52% women, mean age =66 years; standard deviation (SD) 7.3 years] provided information: 61% suffered from panic during the entire breathlessness episode, 39% experienced panic in every episode, and 25% were diagnosed with panic disorder. Exploratory data analysis was conducted. Patients with high scores in breathlessness catastrophizing thoughts experienced more panic in a breathlessness episode (P<0.001) and considered themselves more panic than low-scorers (P=0.024). There was a significant indirect effect of episodic breathlessness intensity on the panic experienced in an episode, and this effect was mediated by catastrophizing thoughts regarding breathlessness (b=0.164; 95% CI: 0.105, 0.222). Patients described in the open-ended question experiencing only panic or breathlessness, or a combination of both. Some patients managed to differentiate panic from episodic breathlessness, and used strategies to avoid panic in an episode. CONCLUSIONS: Research on treatment options for episodic breathlessness should not only focus on panic in breathlessness episodes, but also on underlying mechanisms such as catastrophizing thoughts, as they aggravate the burden.

[Latest news on RA-ILD]. / Aktuelles zur RA-ILD.

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is of high clinical relevance. It not only affects the quality of life but also makes a significant contribution to the mortality rate of patients with rheumatoid arthritis. RA-ILD can present with all known radiological and histopathological patterns seen in other interstitial pneumonias. Among these pneumonias, diffuse alveolar damage (DAD), followed by usual interstitial pneumonia (UIP) has the worst prognosis. In addition, acute exacerbation of RA-ILD, which can occur at any time during the disease, is highly lethal. An algorithm for the diagnosis and treatment of RA-ILD is pending and will be addressed in the following article. In addition to immunosuppressants and disease-modifying antirheumatic drugs (DMARD), antifibrotics have recently gained importance in the therapy of RA-ILD.

The experience of episodic breathlessness from the perspective of informal caregivers: a qualitative interview study.

BACKGROUND: Episodic breathlessness is a common form of chronic breathlessness that is highly distressing for patients with diseases such as chronic obstructive pulmonary disease (COPD) and lung cancer in advanced stages. Little is known about the experiences of informal caregivers who care for patients with episodic breathlessness. The present study aims to explore and describe the experiences and coping strategies of informal caregivers who deal with this challenging condition. METHODS: This is a qualitative study based on semi-structured in-depth interviews with informal caregivers of patients suffering from episodic breathlessness. The interviews were recorded, transcribed verbatim, and analyzed using Mayring's qualitative content analysis. RESULTS: Thirteen informal caregivers were interviewed. The results suggest that the distress patients often experience during episodic breathlessness causes concern and anxiety among most informal caregivers. Particularly stressful for them is their own helplessness and uncertainty, especially when episodic breathlessness occurs for the first time. Over time, all informal caregivers interviewed had developed strategies to cope with the patients' episodic breathlessness. These strategies can be divided into two categories: (I) strategies directed at the patient to provide appropriate support during episodic breathlessness, and (II) strategies aimed at coping with the caregiver's own emotional burden. Despite these strategies, the need for professional support for informal caregivers often remains unmet, especially during the initial onset of episodic breathlessness. CONCLUSIONS: Informal caregivers of patients with chronic breathlessness need support and advice on how to better cope with episodic breathlessness. Both patient and caregiver support need to be part of a comprehensive approach, e.g., as part of a breathlessness service.

Only I Know Now, of Course, How to Deal With it, or Better to Deal With it: A Mixed Methods Phase II Study of a Cognitive and Behavioral Intervention for the Management of Episodic Breathlessness.

CONTEXT: Episodic breathlessness is characterized by increased breathlessness intensity, and it is burdensome for patients. A vicious cycle of breathlessness-anxiety/panic-breathlessness leads to emergencies that can rarely be alleviated by drugs. Non-pharmacological interventions seem to be beneficial: Can a brief cognitive and behavioral intervention help patients to better manage episodic breathlessness? OBJECTIVES: To evaluate the feasibility, safety, acceptability, and potential effects of a brief cognitive and behavioral intervention for the management of episodic breathlessness. METHODS: Between February 2019 and February 2020, 49 patients with life-limiting diseases suffering from episodic breathlessness were enrolled in the single-arm phase II study. The baseline assessment was followed by the one- to two-hour intervention. In weeks two, four, and six after the intervention, the outcomes (main outcome of potential effects: mastery of breathlessness) were assessed, and in week six, a qualitative interview, and the final assessment took place. A mixed-methods approach was used to evaluate mainly the feasibility, including interviewing informal carers. RESULTS: 46/49 patients (24 female; 36 with COPD; mean age: 66.0 years) participated in the baseline assessment, 38 attended the intervention, 32 completed the final assessment, and 22 were interviewed. Study procedures and the intervention were feasible and mainly well accepted and patients did not experience burdens caused by it (28/32). In the interviews, patients described a positive change in their competencies in managing episodic breathlessness and feelings of anxiety during the episode. Mastery of breathlessness improved after the intervention. CONCLUSION: The brief cognitive and behavioral intervention and the study procedures are feasible, safe, and well accepted. We can describe a change for better management of episodic breathlessness in patients after the intervention, still, this needs to be evaluated in a Phase III trial for inclusion in the management of episodic breathlessness.

Detection of circulating tumor DNA by digital droplet PCR in resectable lung cancer as a predictive tool for recurrence.

Lung cancer is the leading cause of cancer-related mortality worldwide due to difficulties in early detection and high postsurgical recurrence rate. Current European Guidelines recommend follow-up via computerized tomography (CT) scans on regular basis within the first 2 years after radical surgical resection. Despite these efforts, recurrence rates remain high with 30-70 %. Therefore, it is imperative to develop predictive markers for metastases and postsurgical recurrence using minimally invasive methods. This prospective study aims at defining the feasibility of detecting circulating tumor DNA (ctDNA) in presurgical plasma samples of patients with lung cancer by digital droplet PCR. Resected tumor tissue and simultaneous blood samples were collected from 24 patients with lung cancer in stage I-IIIA (12 stage I, 8 stage II, 4 stage III). Genomic DNA from the tumor tissue samples were analyzed for hotspot mutations using a 17 gene panel next-generation sequencing (NGS) assay. CtDNA from corresponding plasma samples were analyzed using digital droplet PCR (ddPCR). Additionally, DNA sequencing results were correlated with patients' outcome. At least one somatic mutation was detected by NGS (96 %) in 23 of the tested tissue samples. DdPCR detected mutations in circulating cell-free DNA (ccfDNA) of nine patients' samples (9/23, 39 %). Postsurgical outcome analysis was performed for those patients who had received complete tumor resection (n = 21). Four of them suffered from an early relapse within the first two years after surgery, including two with detectable somatic mutations in ccfDNA during primary staging. Taken together, we showed that the 17 gene panel assay revealed in 23 of 24 patients at least one somatic mutation in the primary tumor by NGS. Tumor-specific mutation was detectable in 39 % from the blood of early stage lung cancer patients by ddPCR.

Overcoming EGFRG724S-mediated osimertinib resistance through unique binding characteristics of second-generation EGFR inhibitors.

The emergence of acquired resistance against targeted drugs remains a major clinical challenge in lung adenocarcinoma patients. In a subgroup of these patients we identified an association between selection of EGFRT790M-negative but EGFRG724S-positive subclones and osimertinib resistance. We demonstrate that EGFRG724S limits the activity of third-generation EGFR inhibitors both in vitro and in vivo. Structural analyses and computational modeling indicate that EGFRG724S mutations may induce a conformation of the glycine-rich loop, which is incompatible with the binding of third-generation TKIs. Systematic inhibitor screening and in-depth kinetic profiling validate these findings and show that second-generation EGFR inhibitors retain kinase affinity and overcome EGFRG724S-mediated resistance. In the case of afatinib this profile translates into a robust reduction of colony formation and tumor growth of EGFRG724S-driven cells. Our data provide a mechanistic basis for the osimertinib-induced selection of EGFRG724S-mutant clones and a rationale to treat these patients with clinically approved second-generation EGFR inhibitors.

Sleep-disordered breathing in patients with cardiovascular diseases cannot be detected by ESS, STOP-BANG, and Berlin questionnaires.

Sleep-disordered breathing (SDB) is highly prevalent in patients with cardiovascular diseases (CVD) and associated with poor outcome. At least 50% of heart failure (HF) patients present with SDB, equally divided in obstructive sleep apnea (OSA) and central sleep apnea (CSA). CVD patients with SDB do not always present with typical SDB symptoms. Therefore, we asked whether established questionnaires allow for the reliable detection of SDB. In this prospective cohort study, 89 CVD patients (54 male, 59 ± 15 years, BMI 30 ± 6 kg/m2) in stable clinical state underwent an ambulatory polygraphy. SDB was defined as an apnea-hypopnea index (AHI) ≥ 15/h. We evaluated the Epworth Sleepiness Scale (ESS), STOP-BANG and Berlin questionnaires as well as anthropometric data and comorbidities regarding their ability to predict SDB. The ESS showed no correlation with SDB. The sensitivity of the Berlin Questionnaire to detect SDB was 73%, specificity was 42%. The STOP-BANG questionnaire showed a sensitivity of 97% while specificity was 13%. Coronary heart disease and/or history of myocardial infarction, hyperuricemia and age significantly contributed to a logistic regression model predicting presence of SDB. However, our regression model explains only 36% of the variance regarding the presence or absence of SDB. The approach to find variables, which would allow an early and reliable differentiation between patients with CVD and coexistence or absence of SDB, failed. Thus, as CVD patients show a high SDB prevalence and poor outcome, only a systematic screening based on measures of respiration-related parameters (i.e., respiratory flow, blood oxygen saturation, etc.) allows for a reliable SDB assessment.

Risk-adapted robotic stereotactic body radiation therapy for inoperable early-stage non-small-cell lung cancer.

PURPOSE: To evaluate efficacy and toxicity of stereotactic body radiation therapy (SBRT) with CyberKnife® (Accuray, Sunnyvale, CA, USA) in a selected cohort of primary, medically inoperable early-stage non-small cell lung cancer (NSCLC) patients. METHODS: From 2012 to 2016, 106 patients (median age 74 years, range 50-94 years) with primary NSCLC were treated with SBRT using CyberKnife®. Histologic confirmation was available in 87 patients (82%). For mediastinal staging, 92 patients (87%) underwent 18F-fluorodeoxyglucose positron-emission tomography (18-FDG-PET) and/or endobronchial ultrasound (EBUS)-guided lymph node biopsy or mediastinoscopy. Tumor stage (UICC8, 2017) was IA/B (T1a-c, 1-3 cm) in 86 patients (81%) and IIA (T2a/b, 3-5 cm) in 20 patients (19%). Depending on tumor localization, three different fractionation schedules were used: 3 fractions of 17Gy, 5 fractions of 11Gy, or 8 fractions of 7.5 Gy. Tracking was based on fiducial implants in 13 patients (12%) and on image guidance without markers in 88%. RESULTS: Median follow-up was 15 months (range 0.5-46 months). Acute side effects were mild (fatigue grade 1-2 in 20% and dyspnea grade 1-2 in 17%). Late effects were observed in 4 patients (4%): 3 patients developed pneumonitis requiring therapy (grade 2) and 1 patient suffered a rib fracture (grade 3). In total, 9/106 patients (8%) experienced a local recurrence, actuarial local control rates were 88% (95% confidence interval, CI, 80-96%) at 2 years and 77% (95%CI 56-98%) at 3 years. The median disease-free survival time was 27 months (95%CI 23-31 months). Overall survival was 77% (95%CI 65-85%) at 2 years and 56% (95%CI 39-73%) at 3 years. CONCLUSION: CyberKnife® lung SBRT which allows for real-time tumor tracking and risk-adapted fractionation achieves satisfactory local control and low toxicity rates in inoperable early-stage primary lung cancer patients.

Short-term and long-term follow-up of pulmonary function in patients with COPD after total laryngectomy: A prospective study.

OBJECTIVE: There exists no standardized method for examining lung function in laryngectomized patients. STUDY DESIGN AND METHODS: We established a base plate adapter (BPA) system for patients after laryngectomy. In 10 patients with chronic obstructive pulmonary disease (COPD), we evaluated pulmonary function before laryngectomy, as well as 2 weeks and 3 months after laryngectomy. RESULTS: The BPA system was well tolerated and delivered reliable results comparable to measurements with a mouthpiece. The parameters forced expiratory volume in one second (FEV1 ), forced vital capacity (FVC), and mean forced expiratory flow between 25% and 75% of forced vital capacity (MFEF25-75 ) changed in the early postoperative examinations (2 weeks postoperative), whereas MFEF25-75 , FEF75 , peak expiratory flow (PEF), and peak inspiratory flow (PIF)) showed differences from baseline in long-term follow-up (3 months postoperative). CONCLUSION: We provide a practicable method of lung function testing in laryngectomized patients with COPD that is essential to tailor inhalation therapy despite tracheotomy. Lung function measurements of laryngectomized patients with COPD should be performed under stable clinical conditions a few weeks after surgery. Guidelines of COPD might be complemented considering the subgroup of laryngectomized patients. LEVEL OF EVIDENCE: 4. Laryngoscope, 127:2045-2049, 2017.

Spectrum of Uveitis in A German Tertiary Center: Review of 474 Consecutive Patients.

PURPOSE: To analyze the spectrum of uveitis at a German tertiary center. PATIENTS AND METHODS: A total of 474 consecutive patients with uveitis were classified according to the primary anatomic site of inflammation, examined for laterality of disease, and screened for etiologies. RESULTS: Out of the total, 253 patients (53%) had anterior uveitis, 90 patients (19%) had intermediate uveitis, 100 patients (21%) had posterior uveitis, and 31 patients (7%) had panuveitis. Fifty-six percent of the patients had bilateral involvement, predominantly in intermediate uveitis (ratio 4:1) and panuveitis (ratio 3.4:1). Regarding the etiology of all uveitis cases we found 17% infectious, 23% specific clinical entities, 20% associated with systemic disease (most commonly sarcoidosis with 11%), and 41% idiopathic uveitis. CONCLUSIONS: Anterior uveitis was the most common anatomic site of intraocular inflammation. Using a tailored approach, screening for systemic etiologies is recommended, since 20% of all patients had associated systemic diseases.

MET amplification status in therapy-naïve adeno- and squamous cell carcinomas of the lung.

PURPOSE: MET is a potential therapeutic target in lung cancer and both MET tyrosine kinase inhibitors and monoclonal antibodies have entered clinical trials. MET signaling can be activated by various mechanisms, including gene amplification. In this study, we aimed to investigate MET amplification status in adeno- and squamous cell carcinomas of the lung. We propose clearly defined amplification scores and provide epidemiologic data on MET amplification in lung cancer. EXPERIMENTAL DESIGN: We evaluated the prevalence of increased MET gene copy numbers in 693 treatment-naïve cancers by FISH, defined clear cutoff criteria, and correlated FISH results to MET IHC. RESULTS: Two thirds (67%) of lung cancers do not have gains in MET gene copy numbers, whereas 3% show a clear-cut high-level amplification (MET/centromer7 ratio ≥2.0 or average gene copy number per nucleus ≥6.0 or ≥10% of tumor cells containing ≥15 MET copies). The remaining cases can be subdivided into intermediate- (6%) and low-level gains (24%). Importantly, MET amplifications occur at equal frequencies in squamous and adenocarcinomas without or with EGFR or KRAS mutations. CONCLUSION: MET amplification is not a mutually exclusive genetic event in therapy-naïve non-small cell lung cancer. Our data suggest that it might be useful to determine MET amplification (i) before EGFR inhibitor treatment to identify possible primary resistance to anti-EGFR treatment, and (ii) to select cases that harbor KRAS mutations additionally to MET amplification and, thus, may not benefit from MET inhibition. Furthermore, our study provides comprehensive epidemiologic data for upcoming trials with various MET inhibitors.

Effects of exogenous surfactant on the non-heart-beating donor lung graft in experimental lung transplantation - a stereological study.

The use of non-heart-beating donor (NHBD) lungs may help to overcome the shortage of lung grafts in clinical lung transplantation, but warm ischaemia and ischaemia/reperfusion injury (I/R injury) resulting in primary graft dysfunction represent a considerable threat. Thus, better strategies for optimized preservation of lung grafts are urgently needed. Surfactant dysfunction has been shown to contribute to I/R injury, and surfactant replacement therapy is effective in enhancing lung function and structural integrity in related rat models. In the present study we hypothesize that surfactant replacement therapy reduces oedema formation in a pig model of NHBD lung transplantation. Oedema formation was quantified with (SF) and without (non-SF) surfactant replacement therapy in interstitial and alveolar compartments by means of design-based stereology in NHBD lungs 7 h after cardiac arrest, reperfusion and transplantation. A sham-operated group served as control. In both NHBD groups, nearly all animals died within the first hours after transplantation due to right heart failure. Both SF and non-SF developed an interstitial oedema of similar degree, as shown by an increase in septal wall volume and arithmetic mean thickness as well as an increase in the volume of peribron-chovascular connective tissue. Regarding intra-alveolar oedema, no statistically significant difference could be found between SF and non-SF. In conclusion, surfactant replacement therapy cannot prevent poor outcome after prolonged warm ischaemia of 7 h in this model. While the beneficial effects of surfactant replacement therapy have been observed in several experimental and clinical studies related to heart-beating donor lungs and cold ischaemia, it is unlikely that surfactant replacement therapy will overcome the shortage of organs in the context of prolonged warm ischaemia, for example, 7 h. Moreover, our data demonstrate that right heart function and dysfunctions of the pulmonary vascular bed are limiting factors that need to be addressed in NHBD.

Surfactant application in experimental lung transplantation.

BACKGROUND: Non-heart-beating donor (NHBD) utilization can significantly increase the limited donor lung pool. However, optimal preservation of organ function is crucial as the development of ischemia/reperfusion injury (IRI) can result in severe surfactant inactivation. Exogenic surfactant application is effective in prevention and therapy of IRI. Studies on optimal timing of Curosurf, including application in NHBDs, have not been done, but could help to optimize NHBD lung transplantation. METHODS: The extracorporeal screening model (ESM) included rat lungs (Sprague-Dawley, n = 5/group) preserved with Perfadex. In 3 test groups, Curosurf was administered before flush preservation (T1), after 4-hour ischemia (T2) or during reperfusion (T3). Results after extracorporeal reperfusion were compared with controls. The transplantation model (TM) consisted of asystolic pigs (n = 5/group) ventilated for 7 hours with warm ischemia (WIT, Groups 1 and 2). In Group 2, 100 mg/kg BW Curosurf was bronchoscopically administered before preservation. After 3-hour cold storage, left lung transplantation was performed and data were compared with sham control data (Group 3). RESULTS: For the ESM, T1 lung oxygenation (SurfT1 167±47.4 mm Hg) was superior to others (SurfT2 47.3±15.3 mm Hg, SurfT3 77.2±48.8 mm Hg, controls 65.5±46.2 mm Hg; p<0.02). Stereology demonstrated poorer intra-alveolar edema formation in controls (1.86±2.53% of parenchyma) compared with surfactant-treated lungs (<0.02% of parenchyma) (p<0.02). Intra-alveolar erythrocyte sequestration as an indicator of vascular leakage was significantly lower in T1 lungs (0.15±0.12% of parenchyma) compared with all other groups (>0.74% of parenchyma). For TM, mortality was 80% in the untreated group and 100% in the Curosurf group, suggesting that a 7-hour WIT is above the limit for NHBD utilization. CONCLUSIONS: Donor lung pre-treatment with endobronchial pre-preservation Curosurf offers optimal preservation quality when compared with post-ischemic application or during reperfusion and results in improved functional outcome when compared with controls. Expensive NHBD pre-treatment with Curosurf cannot improve poor allograft outcome after extended WIT and should therefore not be considered. Seven-hour WIT seems generally to be above the limits for use in NHBD lung donors.

Pneumomediastinum and striking family history: uncommon case of Birt-Hogg-Dubé syndrome.

Birt-Hogg-Dubé syndrome is a rare autosomal dominant condition caused by a germline mutation in the folliculin gene, which is characterized by skin fibrofolliculomas, multiple lung cysts and renal cancer. The clinical expression of the syndrome is highly variable, with recurrent pneumothoraces due to ruptured lung cysts in many cases. We report a patient with pneumomediastinum and cervico-facial emphysema after severe coughing without pneumothorax, skin lesions or renal tumour, but a striking family history of lung abnormalities.

Definition of a fluorescence in-situ hybridization score identifies high- and low-level FGFR1 amplification types in squamous cell lung cancer.

We recently reported fibroblast growth factor receptor-type 1 (FGFR1) amplification to be associated with therapeutically tractable FGFR1 dependency in squamous cell lung cancer. This makes FGFR1 a novel target for directed therapy in these tumors. To reproducibly identify patients for clinical studies, we developed a standardized reading and evaluation strategy for FGFR1 fluorescence in-situ hybridization (FISH) and propose evaluation criteria, describe different patterns of low- and high-level amplifications and report on the prevalence of FGFR1 amplifications in pulmonary carcinomas. A total of 420 lung cancer patients including 307 squamous carcinomas, 100 adenocarcinomas of the lung and 13 carcinomas of other types were analyzed for FGFR1 amplification using a dual color FISH. We found heterogeneous and different patterns of gene copy numbers. FGFR1 amplifications were observed in 20% of pulmonary squamous carcinomas but not in adenocarcinomas. High-level amplification (as defined by an FGFR1/centromer 8 (CEN8) ratio ≥2.0, or average number of FGFR1 signals per tumor cell nucleus ≥6, or the percentage of tumor cells containing ≥15 FGFR1 signals or large clusters ≥10%) was detected at a frequency of 16% and low-level amplification (as defined by ≥5 FGFR1 signals in ≥50% of tumor cells) at a frequency of 4%. We conclude that FGFR1 amplification is one of the most frequent therapeutically tractable genetic lesions in pulmonary carcinomas. Standardized reporting of FGFR1 amplification in squamous carcinomas of the lung will become increasingly important to correlate therapeutic responses with FGFR1 inhibitors in clinical studies. Thus, our reading and evaluation strategy might serve as a basis for identifying patients for ongoing and upcoming clinical trials.

Diabetes-related defects in sarcoplasmic Ca2+ release are prevented by inactivation of G(alpha)11 and G(alpha)q in murine cardiomyocytes.

Neurohumoral stimulation of Gq-coupled receptors has been proposed as a central mechanism in the pathogenesis of diabetic heart disease. The resulting contractile dysfunction is closely related to abnormal intracellular Ca(2+) handling with functional defects of the sarcoplasmic reticulum (SR). The present study was therefore designed to determine the role of G(q)-protein signaling via G(alpha)(11) and G(alpha)(q) in diabetes for the induction of functional and structural changes in the Ca(2+) release complex of the SR. An experimental type 1-diabetes was induced in wild type, G(alpha)(11) knockout, and G(alpha)(11/q)-knockout mice by injection of streptozotocin. Cardiac morphology and function was assessed in vivo by echocardiography. SR Ca(2+) leak was tested in vitro based on a (45)Ca(2+) assay and protein densities as well as gene expression of ryanodine receptor (RyR2), FKBP12.6, sorcin, and annexin A7 were analyzed by immunoblot and RT-PCR. In wild type animals 8 weeks of diabetes resulted in cardiac hypertrophy and SR Ca(2+) leak was increased. In addition, diabetic wild type animals showed reduced protein levels of FKBP12.6 and annexin A7. In G(alpha)(11)- and G(alpha)(11/q)-knockout animals, however, SR Ca(2+) release and cardiac phenotype remained unchanged upon induction of diabetes. Densities of the proteins that we presently analyzed were also unaltered in G(alpha)(11)-knockout mice. G(alpha)(11/q)-knockout animals even showed increased expression of sorcin and annexin A7. Thus, based on the present study we suggest a signaling pathway via the G(q)-proteins, G(alpha)(11) and G(alpha)(q), that could link increased neurohumoral stimulation in diabetes with defective RyR2 channel function by regulating protein expression of FKBP12.6, annexin A7, and sorcin.

Influence of cell treatment with PDGF-BB and reperfusion on cardiac persistence of mononuclear and mesenchymal bone marrow cells after transplantation into acute myocardial infarction in rats.

Bone marrow cells are used for cell therapy after myocardial infarction (MI) with promising results. However, cardiac persistence of transplanted cells is rather low. Here, we investigated strategies to increase the survival and cardiac persistence of mononuclear (MNC) and mesenchymal (MSC) bone marrow cells transplanted into infarcted rat hearts. MNC and MSC (male Fischer 344 rats) were treated with different doses of PDGF-BB prior to intramyocardial injection into border zone of MI (syngeneic females, permanent LAD ligation) and hearts were harvested after 5 days and 3 weeks. In additional experiments, untreated MNC and MSC were injected immediately after permanent or temporary LAD ligation and hearts were harvested after 48 h, 5 days, 3 weeks, and 6 weeks. DNA of the hearts was isolated and the number of donor cells was determined by quantitative real-time PCR with Y chromosome-specific primers. There was a remarkable though not statistically significant (p = 0.08) cell loss of approximately 46% between 5 days and 3 weeks in the control group, which was completely inhibited by treatment with high dose of PDGF-BB. Forty-eight hours after reperfusion only 10% of injected MSC or 1% for MNC were found in the heart, decreasing to 1% for MSC and 0.5% for MNC after 6 weeks. These numbers were lower than after permanent LAD ligation for both MNC and MSC at all time points studied. Treatment with PDGF-BB seems to prevent loss of transplanted bone marrow cells at later times presumably by inhibition of apoptosis, while reperfusion of the occluded artery enhances cell loss at early times putatively due to enhanced early wash-out. Further investigations are needed to substantially improve the persistence and survival of grafted bone marrow cells in infarcted rat hearts, in order to fully explore the therapeutic potential of this novel treatment modality for myocardial repair.