What lab finding is associated with leukopenia?

Leukopenia is defined as a lower than normal white blood cell (WBC) count. This condition can occur due to a variety of factors, including bone marrow disorders, autoimmune diseases, severe infections, or certain medications. The lab finding specifically associated with leukopenia is indeed low white blood cell counts, which directly reflects the condition.

In the context of the other choices, increased red blood cell (RBC) levels, high hemoglobin, and high hematocrit levels are indicators of red cell mass or blood viscosity but do not relate to the status of white blood cells. These factors are more indicative of conditions such as polycythemia or dehydration rather than a decrease in WBCs. Therefore, the direct association of leukopenia with low white blood cell counts is what makes this choice the correct response.