Which laboratory finding is typically seen in a patient with hemolytic uremic syndrome (HUS)?

In patients with hemolytic uremic syndrome (HUS), all the laboratory findings listed are typically observed.

Increased serum bilirubin occurs as a result of the breakdown of red blood cells (hemolysis), which leads to the release of hemoglobin. The hemoglobin is subsequently metabolized to bilirubin, causing elevated levels in the serum. This reflects the compensatory response of the liver to increased hemolysis.

Decreased hemoglobin is also a hallmark finding in HUS due to the destruction of red blood cells in the circulation, which leads to an overall decrease in the red blood cell count and, consequently, hemoglobin levels. The anemia that results can contribute to the clinical symptoms of fatigue and weakness seen in patients.

An elevated reticulocyte count indicates that the bone marrow is responding to the anemia by producing more immature red blood cells, or reticulocytes. This increase is a compensatory mechanism in response to the hemolysis and the decreased red blood cell mass in circulation.

Given that all these laboratory findings are commonly associated with HUS, it is clear that the correct answer encompasses all of the mentioned points, supporting the overall diagnosis and understanding of the syndrome.