{
  "abstract": "Objective Clinical guidelines recommend monitoring of serum creatinine concentrations in users of tenofovir disoproxil/emtricitabine for HIV pre-exposure prophylaxis (PrEP) due to its potential nephrotoxicity. Cystatin C might aid clinicians in determining whether creatinine elevations reflect true kidney injury. We reviewed the use of Cystatin C in our practice.Methods Clinic records from Gay Men’s Health Service were reviewed until March 2024, and those from St. James’s Hospital were reviewed until October 2024, specifically for patients who had a cystatin C test requested due to concerns regarding their renal function. Descriptive statistics were used to analyse the data.Results Seventy PrEP users, with a median age of 39 years (IQR 34–45), were included. Data on body mass index (BMI) and blood pressure were available in 57/70 (81.4%) and 41/70 (58.6%), respectively; 37/57 (64.9%) had a BMI≥ 25 kg/m 2 and 14/41 (34.1%) had hypertension. Protein supplements, creatine and anabolic agents were used by 43/70 (61.4%), 29/70 (41.4%) and 11/70 (15.7%), respectively. Recreational drugs were used by 17/70 (24.3%).The median cystatin C was 0.87 mg/L (IQR 0.81–0.99); 21/70 (30%) had a result above the upper limit of normality. At this time, the median creatinine was 106.5 µmol/L (97–114). An estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 according to Modification of Diet in Renal Disease, Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) (2021), CKD-EPI creatinine-cystatin (2021) and CKD-EPI cystatin C (2012) was found in 11/70 (15.7%), 1/70 (1.4%), 0/70 (0%) and 1/70 (1.4%), respectively. Median eGFR was 67 (61–74), 78 (70–86), 90.5 (82–96), 102.5 (84–111) mL/min/1.73m2, respectively. Urinary protein-to-creatinine ratio was <15 mg/mmol in 65/70 (92.9%), and nobody had significant proteinuria of >50 mg/mmol.Conclusion In this review, the addition of cystatin C to calculate eGFR lessened concerns regarding renal dysfunction, facilitating safe ongoing PrEP prescribing and potentially avoiding unnecessary referral to nephrology services.",
  "authors": [
    {
      "affiliations": [
        "The Department of Genitourinary Medicine and Infectious Diseases, St James’s Hospital, Dublin, Ireland"
      ],
      "name": "Annmarie White"
    },
    {
      "affiliations": [
        "The Department of Genitourinary Medicine and Infectious Diseases, St James’s Hospital, Dublin, Ireland"
      ],
      "name": "Giovanni Villa"
    },
    {
      "affiliations": [
        "The Department of Biochemistry, St James’s Hospital, Dublin, Ireland"
      ],
      "name": "Vivion Crowley"
    },
    {
      "affiliations": [
        "The Department of Genitourinary Medicine and Infectious Diseases, St James’s Hospital, Dublin, Ireland"
      ],
      "name": "Dearbhla Murphy"
    },
    {
      "affiliations": [
        "The Department of Genitourinary Medicine and Infectious Diseases, St James’s Hospital, Dublin, Ireland"
      ],
      "name": "Laura Quinn"
    },
    {
      "affiliations": [
        "The Gay Men’s Health Service, The Meath Primary Care Centre, Dublin, Ireland"
      ],
      "name": "Colm O’Sullivan"
    },
    {
      "affiliations": [
        "The Department of Genitourinary Medicine and Infectious Diseases, St James’s Hospital, Dublin, Ireland",
        "The Gay Men’s Health Service, The Meath Primary Care Centre, Dublin, Ireland"
      ],
      "name": "Grainne Courtney"
    },
    {
      "affiliations": [
        "The Department of Nephrology, St James’s Hospital, Dublin, Ireland"
      ],
      "name": "Brenda Griffin"
    },
    {
      "affiliations": [
        "The Department of Genitourinary Medicine and Infectious Diseases, St James’s Hospital, Dublin, Ireland"
      ],
      "name": "Emma Devitt"
    }
  ],
  "title": "Clinical use of clinician-initiated cystatin C testing in assessing renal function in a subset of patients taking tenofovir disoproxil/emtricitabine as HIV pre-exposure prophylaxis: a retrospective chart review",
  "uid": "be932471-ddfa-5a48-87a5-659d01d098e4"
}