Transgender Man Being Evaluated for a Kidney Transplant

A 33-year-old female-to-male transgender individual (height, 5′1″; weight, 135 lb) presented to emergency care with acute otitis media and hypertension (170/110). Currently prescribed medications include daily atorvastatin and intramuscular testosterone cypionate injections (100 mg/week). The patient refused admission because of discrimination concerns as a transgender man, but presented to his primary care physician the following morning. Laboratory results revealed a urine total protein concentration of 199.5 mg/dL (random collection, 0.0–10.0 mg/dL) and an estimated glomerular filtration rate (eGFR)3 of 31 mL/min/1.73m2 if assessed using the male equation or 23 mL/min/1.73m2 if assessed using the female equation. On the basis of male categorization, the patient was diagnosed with stage 3 chronic kidney disease (CKD3), prescribed carvedilol, and strongly encouraged to discontinue testosterone, to which he agreed. The patient transferred to an alternate institution; here testosterone administration was restarted, lisinopril was prescribed, and reduction in protein and sodium intake was encouraged. Incidentally, the patient had maintained a vegan diet for u003e10 years.Renal transplant evaluation was initiated several months later. Corresponding male eGFR was 24 mL/min/1.73m2, but the corresponding female eGFR was 18 mL/min/1.73m2. Urine protein excretion was 3 g/day. Because transplant candidates require a GFR u003c20 mL/min/1.73m2 (1) and because the patientu0027s male-calculated eGFR was above the cutoff, he was not listed. An evaluation 4 months later documented an eGFR of 21 and 15 mL/min/1.73m2 for corresponding male and female levels, respectively. In the patientu0027s medical chart, only the corresponding male eGFR was documented, and the medical care team did not consider that the sex-based equations will lead to a different interpretation. All eGFR values were calculated using the Modification of Diet in Renal Disease study equation. QUESTIONS TO CONSIDER1. What genetic, biological, and environmental factors can influence creatinine concentration and lead to subsequent uncertainty …