Photo Credit: iStock.com/Mohammed Haneefa Nizamudeen

Michael Bromberg, MD, PhD, talks with Physician’s Weekly about renal disease in patients with paroxysmal nocturnal hemoglobinuria.

“Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal hematopoietic stem cell disease,” researchers wrote in the Journal of Investigative Medicine. “Clinical manifestations include intravascular hemolysis, renal dysfunction, fatigue, jaundice, pulmonary hypertension, and so on. Renal injury, as a clinical feature of PNH, is difficult to diagnose and is one of the causes of death in patients with PNH.”

In their review, the authors examined PNH plus renal injury research to improve clinicians’ understanding of this patient population. They also wanted to improve the accurate and timely staging of disease, thereby improving the initiation of appropriate treatment and decreasing mortality.

Physician’s Weekly (PW) spoke with Michael Bromberg, MD, PhD, who was not involved in the review, to learn more about PNH’s impact on the kidneys.

PW: How common is renal injury in PNH?

Dr. Bromberg: In this review, researchers found that, before the introduction of newer agents that have been used to treat PNH, problems with renal disease were seen more commonly and often were a cause of death in many patients. The most common cause of death for people with PNH is thrombosis, but kidney injury can be seen in these patients.

This review describes both acute and chronic kidney injury. The purpose of this paper is to alert physicians that kidney injury can be a manifestation of PNH. It also reminds clinicians to consider the possibility of kidney injury in patients with anemia with an as-yet-unknown cause.

What are the impacts of renal injury in PNH?

With severe kidney injury, you can have an overall impairment of quality of life for patients who end up on dialysis. That’s the worst-case scenario.

Other syndromes have been associated with PNH, including Fanconi syndrome, which is associated with electrolyte abnormalities. However, the major concern is that if a patient with PNH develops a kidney injury, this could lead to chronic kidney disease (CKD). One of the points they asked about is the impact of CKD in the setting of PNH. Could it be a cause of mortality in these patients?

I see it from the perspective of the hematologist, but one of the points made in this paper is that patients can encounter many manifestations of PNH, including renal disease. In those cases, it would be worth having a consulting nephrologist see the patient and make recommendations to preserve kidney function.

Renal disease is not typically a concern for clinicians evaluating patients with PNH for anemia. We, as hematologists, think about the patient. Patients with unexplained anemia and kidney disease are a little complicated, as patients with kidney disease can be anemic for other reasons. 

How important is cross-specialty collaboration?

 Nephrologists should evaluate patients with PNH to preserve their renal function. Local mechanisms can lead to acute kidney injury or, eventually, CKD. Such an evaluation helps patients avoid end-stage renal disease and the need for dialysis.