This article is from the Interpretation Of Lab Test Profiles, by Ed Uthman firstname.lastname@example.org with numerous contributions by others.
Neutrophilia is seen in any acute insult to the body,
whether infectious or not. Marked neutrophilia
(>25,000/uL) brings up the problem of hematologic
malignancy (leukemia, myelofibrosis) versus reactive
leukocytosis, including "leukemoid reactions." Laboratory
work-up of this problem may include expert review of the
peripheral smear, leukocyte alkaline phosphatase, and
cytogenetic analysis of peripheral blood or marrow
granulocytes. Without cytogenetic analysis, bone marrrow
aspiration and biopsy is of limited value and will not by
itself establish the diagnosis of chronic myelocytic
leukemia versus leukemoid reaction.
Smokers tend to have higher granulocyte counts than
nonsmokers. The usual increment in total wbc count is
1000/uL for each pack per day smoked.
Repeated excess of "bands" in a differential count of a
healthy patient should alert the physician to the
possibility of Pelger-Huet anomaly, the diagnosis of
which can be established by expert review of the
peripheral smear. The manual band count is so poorly
reproducible among observers that it is widely considered
a worthless test. A more reproducible hematologic
criterion for acute phase reaction is the presence in the
smear of any younger forms of the neutrophilic line
(metamyelocyte or younger).
Neutropenia may be paradoxically seen in certain
infections, including typhoid fever, brucellosis, viral
illnesses, rickettsioses, and malaria. Other causes
include aplastic anemia (see list of drugs above),
aleukemic acute leukemias, thyroid disorders,
hypopitituitarism, cirrhosis, and Chediak-Higashi