Iron deficiency anemia (IDA) is a major public health issue, with widespread prevalence and negative impact on health care system.
IDA occurs when iron stores diminish to the level that disturbs erythropoiesis and causes anemia. Neutropenia is an abnormal reduction in the number of neutrophils. A little is known about the association between iron deficiency anemia and neutropenia.
The aim of this study is to investigate the prevalence of neutropenia in a large cohort of adult patients with IDA and to find possible correlation between neutrophil levels with haemoglobin concentration and iron stores. We studied associated infections in this neutropenic group.
Materials and Methods
We retrospectively reviewed the electronic medical records of 1567 patients attended haematology clinic with the diagnosis of IDA ((haemoglobin level less than 12 gm/dl for women, less than 13 gm/dl for men) over the past 2 years in Hamad Medical Corporation, Qatar. Other causes of anemia and anemia associated with any systemic or endocrine disease were excluded. The values of complete blood count (CBC) and iron parameters were collected. Neutropenia was defined as neutrophils count to be less than 1.5x 109/L
Sixty four patients of the 1567 cohort with IDA had neutropenia (4.084%)
Their mean neutrophils count = 1.18 +/- 0.28x 109/L before iron replacement. Neutrophil count increased significantly to 2.33 +/- 1x 109/L after iron therapy (p< 0.05) . No significant correlation was detected between neutrophil count on the one hand and iron level, iron saturation, TIBC, Transferrin and ferritin level on the other hand. Eight out of the 64 patients with neutropenia had infection at the time of presentation; 5 upper respiratory tract infections, 1 gastroenteritis, 1 lymphadenitis, 1 urinary tract infections. Five of these patients received antibiotics, with no complications reported.
In our cohort with IDA the prevalence of neutropenia was 4.08%. In all patients, the neutrophil count returned to normal after proper iron therapy. The effect of iron deficiency on neutrophils count is through its effect on haematopoiesis progenitors and bone marrow microenvironment which regulates the production of cell lineages. In addition, the high level of erythropoietin (observed in IDA) has been shown to down-regulate neutrophil production in animal models.
In another relatively smaller study on 516 patients with IDA, neutropenia was found in 17.6% However, unlike in our study the neutrophil count was correlated with Hb level. On the other hand in 97 patients with unexplained neutropenia, IDA was found in 2.1% with correction of neutrophil count after correction of the anemia. In addition, the associated infection rate was low and was treated without complications.
Our findings support a possible link between IDA and neutropenia evident by the improvement of neutrophils count after iron replacement, (1.18 vs 2.33x 109/).
The finding of neutropenia is not uncommon in patients with IDA. This neutropenia markedly improved after iron replacement. Iron is essential for proper development and maintenance of the immune system in general and further studies are required to elaborate further in this unique association.
No relevant conflicts of interest to declare.
Asterisk with author names denotes non-ASH members.