INTRODUCTION

In 1956 Kostmann¹ described a condition of repeated bacterial infections in infancy that he termed "infantile genetic agranulocytosis." Patients with this condition have chronic neutropenia, and generally have moderate monocytosis and eosinophilia. Their bone marrow examination is characterized by normal concentrations of granulocyte progenitors and precursors, but an arrested neutrophil development at the promyelocyte or myelocyte stage. These patients typically died in early infancy as a result of overwhelming bacterial infections. Nineteen years after his original description, Kostmann reviewed the published cases of this syndrome, adding ten new cases.² Over the subsequent years, 120 patients with Kostmann syndrome have been reported.³ No cases, however, have been reported in a neonate delivered before 33 weeks' gestation, and no cases have been reported in patients cared for in a neonatal intensive care unit (NICU). Because the incidence of preterm delivery is about 7%, and 9% to 10% of all deliveries are admitted to a NICU,⁴ it would have been anticipated that 8 to 12 of the 120 reported patients would have been delivered prematurely or received NICU care.

We recently cared for a neutropenic preterm neonate who died with bacterial sepsis. The neutropenia was ascribed to bacterial infection and no other etiologic explanations were sought. The patient, however, had a twin who also had neutropenia, and in whom the bone marrow aspirate and clinical course were consistent with Kostmann syndrome. On the basis of these twins, we speculate that in preterm infants who die with bacterial sepsis, the diagnosis of Kostmann syndrome can be missed, because their neutropenia can be ascribed solely to bacterial sepsis.⁵ We speculate further that the reason no preterm infants with Kostmann syndrome have been reported is that they have a high likelihood of dying in the NICU from bacterial sepsis, and that when this occurs the underlying cause of their neutropenia is never . . . [Full Text of this Article]