Basophilic stippling is the presence of small coloured grains that are sometimes observed in young red blood cells when the blood is examined under a microscope (smear). The presence of basophilic stippling is reported as “slight,” 1+ to 4+ (“one plus” to “four plus”) depending on the proportion of red blood cells that have it. There are no reference values for this test. Basophilic stippling test results are interpreted in light of other elements of the complete blood count.
Basophilic stippling is found in a variety of clinical conditions such as heavy metal (particularly lead) poisoning and in certain genetic abnormalities of hemoglobin formation such as thalassemia major and minor. Basophilic stippling is also found in liver damage, several forms of anemia, infections, nutritional deficiency and bone marrow disease.