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Texas Medical Center

Adult Allergy and Immunology, Allergy and Immunology
Phone: 832-824-1319
Fax: 832-825-1260


6701 Fannin Street
9th Floor
Houston, TX 77030

Joud Hajjar, MD, MS

Clinic Chief, Adult Allergy and Immunology

Assistant Professor of Medicine, Baylor College of Medicine


School Education Degree Year
Baylor College of Medicine Masters Masters of Science in Clinical Investigations 2017
Virginia Commonwealth University Fellowship Allergy and Immunology 2013
University of Texas MD Anderson Cancer Center Fellowship Hospice/Palliative Care 2011
Indiana University School of Medicine Residency Internal Medicine 2010
American University of Beirut Residency Internal Medicine 2007
University of Aleppo Medical School Doctor of Medicine 2004


Dr. Hajjar’s research is focused on the interplay of the microbiome and immune dysregulation in the antibody deficient host.



The Jeffrey Modell Foundation

The Chao physician-scientist Award

The Immune deficiency foundation

The US immunodeficiency network

Selected Publications

Jiang Y, Firan M, Nandiwada SL, Reyes A, Marsh RA, Vogel TP, Hajjar J. The Natural History of X-Linked Lymphoproliferative Disease (XLP1): Lessons from a Long-Term Survivor. Case Reports Immunol 2020 Aug 26;2020:8841571. doi: 10.1155/2020/8841571. PMID: 32908732; PMCID: PMC7474360.

Noroski L, Das S, Hajjar J. Case 40-2018: A Woman with Recurrent Sinusitis, Cough, and Bronchiectasis. N Engl J Med 2019 Apr 4;380(14):1383. doi: 10.1056/NEJMc1901268. PMID: 30943358.

Joud Hajjar, Nguyen AL, Constantine G, Kutac C, Syed MN, Orange JS, Sullivan KE. Prophylactic Antibiotics Versus Immunoglobulin Replacement in Specific Antibody Deficiency. J Clin Immunol 2020 Jan;40(1):158-164. doi: 10.1007/s10875-019-00716-2. Epub 2019 Nov 22. PMID: 31758281.

Hajjar J, Al-Kaabi A, Kutac C, Dunn J, Shearer WT, Orange JS. Questioning the accuracy of currently available pneumococcal antibody testing. J Allergy Clin Immunol 2018 Oct;142(4):1358-1360. doi: 10.1016/j.jaci.2018.06.013. Epub 2018 Jun 21. PMID: 29936105.

Chinn IK, Chan AY, Chen K, Chou J, Dorsey MJ, Hajjar J, Jongco AM 3rd, Keller MD, Kobrynski LJ, Kumanovics A, Lawrence MG, Leiding JW, Lugar PL, Orange JS, Patel K, Platt CD, Puck JM, Raje N, Romberg N, Slack MA, Sullivan KE, Tarrant TK, Torgerson TR, Walter JE. Diagnostic interpretation of genetic studies in patients with primary immunodeficiency diseases: A working group report of the Primary Immunodeficiency Diseases Committee of the American Academy of Allergy, Asthma & Immunology. J Allergy Clin Immunol 2020 Jan;145(1):46-69. doi: 10.1016/j.jaci.2019.09.009. Epub 2019 Sep 27. PMID: 31568798.

Heimall JR, Hagin D, Hajjar J, Henrickson SE, Hernandez-Trujillo HS, Tan Y, Kobrynski L, Paris K, Torgerson TR, Verbsky JW, Wasserman RL, Hsieh EWY, Blessing JJ, Chou JS, Lawrence MG, Marsh RA, Rosenzweig SD, Orange JS, Abraham RS. Use of Genetic Testing for Primary Immunodeficiency Patients. J Clin Immunol 2018 Apr;38(3):320-329. doi: 10.1007/s10875-018-0489-8. Epub 2018 Apr 19. Erratum in: J Clin Immunol. 2018 May 21;: PMID: 29675737.


Norton Rose Fulbright Faculty Excellence Award, 2020

Texas Top Docs, 2020

Castle Connolly Top Doctor, 2020

Castle Connolly Exceptional Women in Medicine, 2019

Castle Connolly Top Doctor, 2019

Texas Top Docs, 2019

Patient and Family Comments

* Texas Children's Hospital physicians' licenses and credentials are reviewed prior to practicing at any of our facilities. Sections titled From the Doctor, Professional Organizations and Publications were provided by the physician's office and were not verified by Texas Children's Hospital.