**12. Hematopoietic growth factors (HGF)**

Since 1985, two-thirds of reported cases of idiosyncratic agranulocytosis have been treated with HGF, especially *granulocyte-colony stimulating factor* (G-CSF) [9]. The most recent, major studies on hematopoietic growth factors (HGF) use in drug-induced agranulocytosis are described in **Table 4** [2, 5, 10–15]. In our aforementioned cohort, a faster hematological nonsignificantly recovery (neutrophil count >1.5 × 10<sup>9</sup> /L) was observed in the HGF group: 2.1 days


G-CSF: Granulocyte-Colony Stimulating factor; GM-CSF: Granulocyte-Macrophage-Colony Stimulating factor

**Table 4.** Recent studies on the use of hematopoietic growth factors in idiosyncratic drug-induced agranulocytosis.

(*p* = 0.057) [5]. Thus, for certain hematologist, the usefulness of HGF remains controversy in such patients. To support this view, the only available prospective randomized study (based on 24 patients with antithyroid-related agranulocytosis) did not confirm the benefit of G-CSF [10]. Nevertheless, this negative result may be related to inappropriate G-CSF doses (100–200 μg/day).

To date, no data is available on the use of pegfilgrastim (a long-acting recombinant G-CSF) in idiosyncratic drug-induced neutropenia [2, 3].

In this setting, it is important to keep in mind that transfusion of granulocyte concentrates should only be used in exceptional circumstances, and only then for the control of lifethreatening infections with antibiotic resistance such as perineal gangrene [2].
