What finding is likely in patients with renal papillary necrosis and sickle cell disease?

In patients with renal papillary necrosis, particularly those with sickle cell disease, it is common to observe flank pain along with gross hematuria. This occurs due to the reduced blood flow to the renal papillae as a result of sickling of red blood cells within the vasa recta, the small blood vessels that supply the renal medulla. When these blood vessels become obstructed, it leads to ischemia and subsequent necrosis of the renal papillae. This ischemic damage can trigger inflammation and bleeding, resulting in hematuria (blood in the urine). The flank pain is often the result of stretching of the renal capsule or irritation of the renal nerves due to inflammation.

This clinical presentation is distinctive in sickle cell disease patients due to the unique pathophysiological mechanisms involved. While other findings such as infection or chronic kidney disease can occur in these patients, the specific combination of flank pain and gross hematuria directly correlates to the ischemic changes stemming from renal papillary necrosis associated with sickle cell-related vaso-occlusive crises.