G NAGARAJU1, C CLARK1
1Capital and Coast DHB, Wellington, New Zealand
Background- Immune checkpoint inhibitor, (Anti PD 1 antibody) Pembrolizumab became widely accessible in New Zealand in 2016 for its use in metastatic melanoma. The immune mediated adverse reactions include dermatitis, pneumonitis, colitis, hypophysitis, uveitis, hypothyroidism hepatitis and nephritis. However, immune interstitial nephritis is an increasing side effect being noticed in patients treated Pembrolizumab. We report 2 cases of acute kidney injury related to Pembrolizumab used for treatment of metastatic melanoma.
Case 1 – 54 year old Caucasian lady with known metastatic melanoma developed acute kidney injury following 20 cycles of Pembrolizumab. Usual suspects for acute kidney injury were ruled out. A renal biopsy was performed which revealed interstitial nephritis. Pembrolizumab was discontinued and oral prednisone at a dose of 60 mg was initiated. This was tapered over 3 months. The renal function improved with prednisone but serum creatinine remains slightly above baseline levels. A CT scan performed 5months after discontinuing Pembrolizumab showed melanoma in remission. An expectant approach has been undertaken in the management currently.
Case 2- Within a short time interval since case 1 a 77 year old Caucasian gentleman with metastatic melanoma and HTN received Pembrolizumab. After 8 cycles he was noted to have acute kidney injury. Although he was on anti-hypertensive, the only new medication was Pembrolizumab. Biopsy was not warranted as stopping Pembrolizumab caused prompt improvement of renal function.
Conclusions-With increasing use of Immune checkpoint inhibitors the incidence of kidney injury is likely to increase. Treating physicians and in particular nephrologists need to be aware of the effects of these newer agents. The need for further studies to formalize an approach in managing these issues is warranted.
Dr Gunashree Nagaraju – I am a first year Renal advance trainee (AT) at Wellington Hospital.
I graduated from Rajiv Gandhi University of Health Sciences , Bangalore , India.