Vitamin B12 The causes of<unk>  can be divided between problems that are transient and those that are chronic. Causes can be divided into these groups: Severe bacterial infections, especially in people with underlying hematological diseases or alcoholism, can deplete neutrophil reserves and lead to<unk> . Gram-positive bacteria are present in 60–70% of bacterial infections. There are serious concerns regarding antibiotic-resistant organisms. These would include as methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE). Nutritional deficiencies, such as deficiency in vitamin B12, folate, copper or protein-calorie malnutrition are associated with chronic<unk> . However, nutritional deficiencies are usually associated with decreases in other cell lines (multiple cytopenia or pancytopenia) rather than isolated<unk> . Other causes of congenital<unk>  are Shwachman–Diamond syndrome, Cyclic<unk> , bone marrow failure syndromes, cartilage–hair hypoplasia, reticular dysgenesis, and Barth syndrome. Viruses that infect neutrophil progenitors can also be the cause of<unk> . Viruses identified that have an effect on neutrophils are rubella and cytomegalovirus. Though the body can manufacture a normal level of neutrophils, in some cases the destruction of excessive numbers of neutrophils can lead to<unk> . These are:
Neutropenia
Monocytosis
Macrocytosis
Poikilocytosis
Mastocytosis
Monocytopenia
Hypersegmented neutrophil
Dyscrasia