Editor-in-Chief, 23rd March 2017

Author s response to reviews Title: Single Use and Conventional Bronchoscopes for Broncho alveolar Lavage (BAL) in research: A comparative study (NCT 02515591) Authors: Seher Raza Zaidi (seher.zaidi@lstmed.ac.uk) Andrea Collins (andreamcollins@yahoo.com) Elena Mitsi (elena.mitsi@lstmed.ac.uk) Jesús Reiné (jesus.reine@lstmed.ac.uk) Kayleigh Davies (kayleigh.davies@rlbuht.nhs.uk) Angela Wright (a.d.wright@liverpool.ac.uk) Jessica Owugha (jessica.owugha@lstmed.ac.uk) Richard Fitzgerald (richard.fitzgerald@rlbuht.nhs.uk) Amitava Ganguli (a.ganguli@liverpool.ac.uk) Stephen Gordon (stephen.gordon@lstmed.ac.uk) Daniela Ferreira (daniela.ferreira@lstmed.ac.uk) Jamie Rylance (jamie.rylance@lstmed.ac.uk) Version: 1 Date: 03 Apr 2017 Author s response to reviews: Editor-in-Chief, 23rd March 2017 BMC Pulmonary Medicine Dear Editor, Thank you for your letter dated February 21st 2017, regarding our manuscript entitled Single Use and Conventional Bronchoscopes for Broncho alveolar Lavage (BAL) in research: A comparative study (NCT 02515591)" (PULM-D-17-00014). We have now addressed all your

referees comments and revised the manuscript accordingly (see point-by-point answers and changes below). The authors Editor s comments 1. Please amend the statement in the "Consent for publication" section. This consent refers to consent for publication of potentially-identifying information of participants or patients. If your manuscript contains any individual person s data in any form (including individual details, images or videos), consent to publish must be obtained from that person, or in the case of children, their parent or legal guardian. Please provide details of this consent in this section. If your manuscript does not contain any individual person s identifiable data or information, please state Not applicable under this section. ANSWER: Thank you, we have changed this to read as not-applicable. 2. Please provide the trial registration information at the end of the abstract, as per our submissionguidelines.https://bmcpulmmed.biomedcentral.com/submissionguidelines/preparingyour-manuscript/research-article. Trial registration: If your article reports the results of a health care intervention on human participants, it must be registered in an appropriate registry and the registration number and date of registration should be in stated in this section. If it was not registered prospectively (before enrolment of the first participant), you should include the words 'retrospectively registered'. See our editorial policies for more information on trial registration ANSWER: Thank you, we have added this at the end of the abstract. 3. Figures should be provided as separate files, and each figure of a manuscript should be submitted as a single file. Each figure is now attached as a separate file, with no legends in these as per the instructions. ANSWER: Thank you, we have added this, as per to the submission guidelines. 4. Please provide figure titles/legends under a separate heading of 'Figure Legends' after the References. If Figure titles/legends are within the main text of the manuscript, please move them. Figure files should contain only the image/graphic, as well as any associated keys/annotations. If titles/legends are present within the figure files, please remove them. ANSWER: Completed. We have moved the figure legends from the main manuscript to the end after the references as requested.

Reviewer 1: This article describes the use of disposable bronchoscopes in the research setting. One of the major concerns I have is that the comparison group is not described in the methods or results section other than statics related to BAL yield. Detailed comments are below. ABSTRACT In the background section I would change sentence "... and may also carry a small risk of cross infection" to "... and carries a small risk of cross infection." since bronchoscopy is known to have a risk of infection. In the results section and whole of paper, please change p value to two decimal places. ANSWER: We have changed this to read as carries a small risk of infection The p values were up to two decimal places for total cell yield and cell viability, and the volume yield has now been changed to read as <0.01. Thank you PAPER BACKGROUND 1)The first sentence "flexible fibre optic bronchoscopy" is incorrect. For the last decade, most countries have been using video bronchoscopes and fibre optic scopes are relics of third world medicine. Change to just flexible bronchoscopy. Answer: Thank you, this now reads as flexible bronchoscopy. 2) Line 20 reword to "...of various diffuse lung diseases (3-7). It is used in early phase drug development studies and has a proven safety record in both research and clinical application. BAL is easily performed and well-tolerated with rare complications (8-10)." ANSWER: Thank you, we have changed as described above. 3) Page 2 Line 43 reword to "... bronchoscopes with regard to BAL volumes, cell yield and viability using each method." ANSWER: Thank you, we have re worded this as suggested. RECRUITMENT AND BRONCHOSCOPY We are given no details of the comparison group in this study. Who are they --- age? number? Health status? Were these healthy volunteers also or did they have underlying lung disease that may affect BAL yields and cell #s. The authors need to either include this information for the reader to make an educated comparison or admit comparison all together and report only on the health volunteers and the disposable scopes.

ANSWER: Completed. We have added the gender demographics of the healthy controls with comparison between the two groups. DISCUSSION Line 112... is reference 8 correct? The sentence reads like data presentation but the reference is a video of BAL technique. ANSWER: Thank you, this is from our unpublished data and we have removed this sentence from the manuscript. Some of the values used for comparison from conventional bronchoscope, are from this unpublished data. The reference was to the video link which demonstrates our technique. Reviewer 2: Overall a well-done and necessary trial. It is clear that the AmbuScope can generate a slightly higher ml yield of BALF and has the same %viability of cells. The disposable single/use scope could prove overall less expensive since there is less infrastructure involved in its use. There was a higher proportion of males in the AmbuScope group than the conventional bronchoscopy group. This should be explained. In particular, there is some suggestion that the slightly larger airways of equivalently sized males may have a slightly larger airway diameter which would in turn suggest the possibility of improved yield. I suggest that an extra table that breaks out relative yield of disposable vs conventional BAL by gender be shown to demonstrate that there is no gender bias influencing the results. ANSWER: We have looked at these values for all the participants separating by gender, and did not find a difference. Overall the volume yield is similar. This has been observed in other studies as well. I have attached a reference for a study describing this(1). This has also been added to manuscript. Female Median (IQR) Male Median (IQR) BAL Volume Yield Combined 128ml (113-146) 127.5ml (104-140) In the interest of Open Access, many journals suggest the publication of the de identified individual data set on line. That would be helpful to the scientific community. Answer: Thank you, the data in the format of an excel sheet, along with the accepted article will be available via the online repository of Liverpool School of Tropical Medicine. This can be accessed using the link below:

http://archive.lstmed.ac.uk/ Cell counts were demonstrated, which is important in the evaluation of inflammatory response from a cellular level. However, there is interest in demonstrating BALF supernatant cytokine data (e.g. LTC4, IL4, etc). This paper would be much strengthened if assays of both conventional and AmbuScope BALF was analysed for at least one cytokine. It would have to be a nonpathologic one since these are all healthy volunteers. Alternatively, the authors may be considering a separate submission to address the issues of a variety of cytokine that use a variety of different techniques for measurement (HPLC, DFA, Antibody-electrophoresis, etc). ANSWER: Thank you we will consider submitting such a publication, and have therefore not elaborated on this within the current manuscript. Thank you Your Sincerely Authors If improvements to the English language within your manuscript have been requested, you should have your manuscript reviewed by someone who is fluent in English. If you would like professional help in revising this manuscript, you can use any reputable English language editing service. We can recommend our affiliates Nature Research Editing Service (http://bit.ly/nres_bs) and American Journal Experts (http://bit.ly/aje_bs) for help with English usage. Please note that use of an editing service is neither a requirement nor a guarantee of publication. Free assistance is available from our English language tutorial (https://www.springer.com/gb/authors-editors/authorandreviewertutorials/writinginenglish) and our Writing resources (http://www.biomedcentral.com/getpublished/writing-resources). These cover common mistakes that occur when writing in English. --------------------Editorial Policies-------------------- Please read the following information and revise your manuscript as necessary. If your manuscript does not adhere to our editorial requirements, this may cause a delay while this is addressed. Failure to adhere to our policies may result in rejection of your manuscript. In accordance with BioMed Central editorial policies and formatting guidelines, all manuscript submissions to BMC Pulmonary Medicine must contain a Declarations section which includes the mandatory sub-sections listed below. Please refer to the journal's Submission Guidelines web page for information regarding the criteria for each sub-section (https://bmcpulmmed.biomedcentral.com/).

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