Christian Avery Merlo, M.D., M.P.H.

Headshot of Christian Avery Merlo
  • Director of Outpatient Clinical Operations
  • Associate Professor of Medicine


Cystic Fibrosis, Lung Transplant, Pulmonary and Critical Care Medicine more

Research Interests

HIV-related pulmonary disease; Outcomes after lung transplantation; Clinical outcomes in cystic fibrosis more

Request an Appointment

Insurance Information

Main Phone

Outside of Maryland & Washington D.C.

Request Appointment

International Patients

Request Appointment


The Johns Hopkins Hospital (Main Entrance)

Appointment Phone: 410-550-5864
1800 Orleans St.
Sheikh Zayed Tower
Baltimore, MD 21287
Phone: 410-955-3467
The Johns Hopkins Hospital (Main Entrance) - Google Maps

Johns Hopkins Outpatient Center (now called Levi Watkins, Jr., M.D., Outpatient Center)

Appointment Phone: 410-955-2000
601 N. Caroline St.
Baltimore, MD 21287
Phone: 410-955-9434
Johns Hopkins Outpatient Center (now called Levi Watkins, Jr., M.D., Outpatient Center) - Google Maps

Johns Hopkins Bayview Medical Center

Appointment Phone: 410-550-5864
4940 Eastern Avenue
Baltimore, MD 21224
Johns Hopkins Bayview Medical Center - Google Maps


Dr. Merlo is an internist who specializes in pulmonary and critical care medicine.  Dr. Merlo also has clinical expertise in the care of patients with cystic fibrosis as well as clinical expertise in the care of patients with advanced lung disease who may require or have undergone lung transplantation. Dr. Merlo holds a joint appointment in epidemiology at the Johns Hopkins Bloomberg School of Public Health.

Dr. Merlo attended the College of the Holy Cross and completed medical school and residency training in internal medicine at Georgetown University. He completed both clinical and research fellowships in pulmonary and critical care medicine at Johns Hopkins, and earned his M.P.H. at the Bloomberg School of Public Health. 

His research interests include outcomes in lung transplantation and cystic fibrosis, HIV-related pulmonary disease, and outcomes in Osler Weber Rendu. 

Dr. Merlo serves as the Associate Program Director of Scholarship for the Osler Medical Housestaff Training Program. He has contributed numerous scientific papers and book chapters related to cystic fibrosis and lung transplantation, and his awards include the Harry Shwachman Clinical Investigator Award from the Cystic Fibrosis Foundation. more


  • Director of Outpatient Clinical Operations
  • Associate Professor of Medicine

Departments / Divisions

Centers & Institutes



  • MD; Georgetown University School of Medicine (1996)


  • Internal Medicine; MedStar Health (2000)


  • Pulmonary and Critical Care Medicine; Johns Hopkins University School of Medicine (2004)

Research & Publications

Research Summary

Dr. Merlo’s research is focused on outcomes in patients with cystic fibrosis and specifically studies the effect of infection, genetics, and the environment in cystic fibrosis.  His research also focuses on the transition process for those patients with advanced lung disease who may require lung transplantation as well as outcomes and predictors of survival after lung transplantation.

Selected Publications

View all on PubMed

Grimm JC, Valero V 3rd, Magruder JT, Kilic A, Dungan SP, Silhan LL, Shah PD, Kim BS, Merlo CA, Sciortino CM, Shah AS. “A novel risk score that incorporates recipient and donor variables to predict 1-year mortality in the current era of lung transplantation.” J Heart Lung Transplant. 2015 Jul 22. pii: S1053-2498(15)01358-3. doi: 10.1016/j.healun.2015.07.001. [Epub ahead of print]

Braun AT, Dasenbrook EC, Shah AS, Orens JB, Merlo CA. “Impact of lung allocation score on survival in cystic fibrosis lung transplant recipients.” J Heart Lung Transplant. 2015 Jun 11. pii: S1053-2498(15)01294-2. doi: 10.1016/j.healun.2015.05.020. [Epub ahead of print]

Grimm JC, Valero V 3rd, Kilic A, Magruder JT, Merlo CA, Shah PD, Shah AS. “Association between prolonged graft ischemia and primary graft failure or survival following lung transplantation.” JAMA Surg. 2015 Jun;150(6):547-53. doi: 10.1001/jamasurg.2015.12.

Merlo CA, Clark SC, Arnaoutakis GJ, Yonan N, Thomas D, Simon A, Thompson R, Thomas H, Orens J, Shah AS. “National healthcare delivery systems influence lung transplant outcomes for cystic fibrosis.” Am J Transplant. 2015 Jul;15(7):1948-57. doi: 10.1111/ajt.13226. Epub 2015 Mar 24.

Grimm JC, Valero V 3rd, Kilic A, Crawford TC, Conte JV, Merlo CA, Shah PD, Shah AS. “Preoperative performance status impacts perioperative morbidity and mortality after lung transplantation.” Ann Thorac Surg. 2015 Feb;99(2):482-9. doi: 10.1016/j.athoracsur.2014.09.038. Epub 2014 Dec 18.

Merlo CA, Yin LX, Hoag JB, Mitchell SE, Reh DD. “The effects of epistaxis on health-related quality of life in patients with hereditary hemorrhagic telangiectasia.” Int Forum Allergy Rhinol. 2014 Nov;4(11):921-5. doi: 10.1002/alr.21374. Epub 2014 Aug 21.

Fischer WA 2nd, Drummond MB, Merlo CA, Thomas DL, Brown R, Mehta SH, Wise RA, Kirk GD. “Hepatitis C virus infection is not an independent risk factor for obstructive lung disease.” COPD. 2014 Feb;11(1):10-6. doi: 10.3109/15412555.2013.800854. Epub 2013 Jul 17.

Eberlein M, Reed RM, Maidaa M, Bolukbas S, Arnaoutakis GJ, Orens JB, Brower RG, Merlo CA, Hunsicker LG. Donor-recipient size matching and survival after lung transplantation. A cohort study. Ann Am Thorac Soc. 2013 Oct;10(5):418-25. doi: 10.1513/AnnalsATS.201301-008OC. PMID: 23988005 

Kilic A, Beaty CA, Merlo CA, Conte JV, Shah AS. Functional status is highly predictive of outcomes after redo lung transplantation: an analysis of 390 cases in the modern era. Ann Thorac Surg. 2013 Nov;96(5):1804-11; discussion 1811. doi: 10.1016/j.athoracsur.2013.05.080. Epub 2013 Aug 20. PMID: 23968759

Eberlein M, Diehl E, Bolukbas S, Merlo CA, Reed RM. An oversized allograft is associated with improved survival after lung transplantation for idiopathic pulmonary arterial hypertension. J Heart Lung Transplant. 2013 Dec;32(12):1172-8. doi: 10.1016/j.healun.2013.06.011. Epub 2013 Jul 19. PMID: 23876630

Fischer Ii WA, Drummond MB, Merlo CA, Thomas DL, Brown R, Mehta SH, Wise RA, Kirk GD. Hepatitis C Virus Infection Is Not An Independent Risk Factor For Obstructive Lung Disease. COPD. 2013 Jul 17. [Epub ahead of print] PMID: 23862666

Eberlein M, Reed RM, Bolukbas S, Parekh KR, Arnaoutakis GJ, Orens JB, Brower RG, Shah AS, Hunsicker L, Merlo CA. Lung size mismatch and survival after single and bilateral lung transplantation. Ann Thorac Surg. 2013 Aug;96(2):457-63. doi: 10.1016/j.athoracsur.2013.04.064. Epub 2013 Jun 26. PMID: 23809729

Lambert AA, Merlo CA, Kirk GD. Human immunodeficiency virus-associated lung malignancies. Clin Chest Med. 2013 Jun;34(2):255-72. doi: 10.1016/j.ccm.2013.01.008. Epub 2013 Apr 8. Review. PMID: 23702175

Reh DD, Hur K, Merlo CA. Efficacy of a topical sesame/rose geranium oil compound in patients with hereditary hemorrhagic telangiectasia associated epistaxis. Laryngoscope. 2013 Apr;123(4):820-2. doi: 10.1002/lary.23736. Epub 2013 Feb 9. PMID: 23401038

Yarmus L, Akulian J, Gilbert C, Illei P, Shah P, Merlo C, Orens J, Feller-Kopman D. Cryoprobe transbronchial lung biopsy in patients after lung transplantation: a pilot safety study. Chest. 2013 Mar;143(3):621-6. PMID: 23328889

Drummond MB, Merlo CA, Astemborski J, Kalmin MM, Kisalu A, Mcdyer JF, Mehta SH, Brown RH, Wise RA, Kirk GD. The effect of HIV infection on longitudinal lung function decline among IDUs: a prospective cohort. AIDS. 2013 May 15;27(8):1303-11. doi: 10.1097/QAD.0b013e32835e395d. PMID: 23299176

Kilic A, Shah AS, Merlo CA, Gourin CG, Lidor AO. Early outcomes of antireflux surgery for United States lung transplant recipients. Surg Endosc. 2013 May;27(5):1754-60. doi: 10.1007/s00464-012-2674-9. Epub 2012 Dec 28. PMID: 23271270

Academic Affiliations & Courses

Graduate Program Affiliation

Bloomberg School of Public Health, Department of Epidemiology

Activities & Honors


  • Harry Shwachman Clinical Investigator Award, Cystic Fibrosis Foundation
Is this you? Edit Profile
back to top button