The Leslie Brent Laboratory (UKAS accredited, 9280) is part of the kidney and transplant services within the division of medicine and integrated care at Imperial College Healthcare.

We provide a therapeutic drug monitoring service for the measurement of immunosuppressive and immunomodulatory drugs for patients who have had a transplant or who have immune-based disorders.

It is open 09.00 to 17.00, Monday to Friday, and one day each bank holiday weekend.

GPs and other care providers can request analysis of blood samples to monitor:

  • tacrolimus – ethylenediaminetetraacetic acid (EDTA) or ‘purple top’ sample required
  • ciclosporin – EDTA sample required
  • mycophenolic acid (MPA) – EDTA or serum sample required (no gel tubes)
  • sirolimus – EDTA sample required
  • hydroxychloroquine (HCQ) – EDTA sample required
  • 5-flucytosine (5-FC) – serum required (‘red top’, no gel tubes)
  • itraconazole – serum required (red top, no gel tubes)
  • hydroxy-itraconazole – serum required (red top, no gel tubes)
  • posaconazole – serum required (red top, no gel tubes)
  • voriconazole – serum required (red top, no gel tubes)

There are no appointments or drop ins for patients. GPs can request tests without referring patients by completing a laboratory request form and sending samples directly. Please see our user guide for more information. 

The laboratory provides a same-day service for ciclosporin and tacrolimus analysis from Monday to Friday, if a patient sample is received at the laboratory by 13.30 that day. The other tests are done on:

  • MPA levels – twice a week (Mondays and Thursdays)
  • sirolimus levels – twice a week (Mondays and Thursdays)
  • HCQ levels – Wednesday
  • anti-fungal drug levels (5-FC, itraconazole, hydroxy-itraconazole, posaconazole, voriconazole) – twice a week (Tuesday and Fridays only)

The laboratory is located on the ground floor of the F block building at Hammersmith Hospital.

For clinical support, advice and guidance, GPs and other care providers can call:

  • Dr Tom Cairns, laboratory director 
    020 3313 5175
  • Dr Janet Lee, laboratory manager 
    020 3313 6639 

Satellite Units


The Renal Directorate coordinates out-patient clinics, in-patient reviews and provision of dialysis at a number of other hospital sites across NWL including; Ashford, Charing Cross, Central Middlesex, Chelsea and Westminster, Ealing, Hillingdon, Northwick Park, St Mary’s, St Charles, Watford, West Middlesex and the Hayes Dialysis Unit.