Traditionally, physiological differences between the sexes have led to sex-specific reference ranges for reporting and interpretation of many laboratory tests such as the complete blood count (CBC). While of practical and clinical relevance, sex-specific reference ranges may be ineffective or even misleading for clinical assessment of the transgender population. Transgender individuals experience discordance between their biological sex (referring to anatomy and chromosomes) and their gender identity (defined as a person’s psychological identification with a given gender). This discordance often results in psychological distress known as gender dysphoria. Transgender individuals can experience relief from gender dysphoria by transitioning, using social and medical procedures to affirm their gender identity (1). Medical procedures to affirm gender identity may include hormone replacement therapy and/or surgeries.
Multiple groups have reported significant changes in basic chemistry, endocrine, and hematologic parameters in transgender patients receiving hormone therapy (1). Our retrospective review of laboratory testing in transgender patients who receive care at University of Iowa Health Care’s LGBTQ Clinic demonstrated some similarities to previous studies when comparing lab results prior to initiation of hormone therapy versus six or twelve months after initiation (2). We replicated previous findings concerning CBC parameters in transgender individuals on both masculinizing and feminizing therapy. Like other studies, we observed significant increases in creatinine in transgender individuals receiving testosterone, likely due to testosterone’s anabolic effects such as increased muscle mass. Compared to earlier studies, our patient cohort demonstrated different responses to hormone therapy when considering some components of the basic metabolic panel, liver function tests, and lipid panel. Carefully designed prospective reference range studies in the transgender population are necessary to accurately determine normative laboratory data.
There are multiple obstacles to studying the impact of hormone therapy on laboratory testing and functionally establishing reference ranges for the transgender population. One of the most significant barriers in our experience is the limited functionality of the electronic medical record (3). At our institution, a single variable is used to designate sex. We discovered there was no reliability to whether this variable reflected sex assigned at birth, gender identity, or legal sex. As a result, for our retrospective study, extensive chart review was required for each patient to determine if they belonged in the cohort on masculinizing therapy, feminizing therapy, or neither. A host of challenges are posed by current functionality of electronic medical records. These include issues with patient identification for individuals whose preferred name does not match their legal name, identification of preferred pronouns by scheduling and phlebotomy staff, billing and coding rules based on binary male/female classification (e.g., pregnancy, prostate testing), blood donation eligibility criteria with sex-specific criteria, communication with reference laboratory and outreach interfaces lacking functionality for transmitting gender identity, and the impact of hormone therapy on interpretation of pap smears and some biopsies. Fortunately, vendors of electronic medical records are starting to incorporate functionality to better serve transgender patient care. The clinical laboratory will play an essential role moving forward as we strive to provide inclusive, evidence-based guidance for clinicians caring for the transgender population.
- Goldstein Z, Corneil TA, Greene DN. When Gender Identity Doesn’t Equal Sex Recorded at Birth: The Role of the Laboratory in Providing Effective Healthcare to the Transgender Community. Clinical Chemistry. 2017;63(8):1342-1352. doi:10.1373/clinchem.2016.258780
- Humble RM, Imborek KL, Nisly N, Greene DN, Krasowski MD. Common Hormone Therapies Used to Care for Transgender Patients Influence Laboratory Results. The Journal of Applied Laboratory Medicine. 2018;3(5):799-814. doi:10.1373/jalm.2018.027078
- Krasowski M, Imborek K, Nisly N, et al. Preferred names, preferred pronouns, and gender identity in the electronic medical record and laboratory information system: Is pathology ready? Journal of Pathology Informatics. 2017;8(1):42. doi:10.4103/jpi.jpi_52_17