Neutropenias of childhood

Congenital dysgranulopoietic neutropenia in two siblings: clinical, ultrastructural, and in vitro bone marrow culture studies

Two siblings with congenital neutropenia are reported. The first patient, female, died after Pseudomonas sepsis. The second patient male, suffered from recurrent pyogenic infections, with a more benign course. Bone Marrow (BM) and Peripheral Blood (PB) analysis in the second patient revealed a reduced number of granules and myelin bodies in the PB neutrophils, suggesting a developmental defect of primary and secondary granules. BM promyelocytes were almost normal, but the myelocytes and metamyelocytes showed defective granulogenesis. The BM in vitro granulocyte-macrophage-colony-forming cell (GM-CFC) growth and the PB white blood cells (WBC) granulocyte-macrophage-colony-stimulating factor (GM-CSF) production, which were analyzed in the second patient, showed normal numbers of GM-CFC, with differentiation mostly toward monocytes and a defect in the GM-CSF production capacity. The second patient's PB mononuclear cells or serum did not inhibit normal GM-CFC when added to control BM cells. We suggest that in this specific form of congenital neutropenia, which is probably an autosomal recessive disorder, the abnormal neutrophil granule production and the defective provision of GM-CSF by PB WBC are unique pathognomonic characteristics, possibly associated with the overt neutropenia.

Morphologic and functional heterogeneity of chronic neutropenia of childhood with normal neutrophil colony formation in vitro

In order to obtain further knowledge of chronic neutropenia of childhood, we studied nine neutropenic infants six to ten months of age by in vitro techniques, including bone marrow culture, electron microscopy, and chemotaxis assay. Eight of the nine patients had a benign clinical course and the bone marrow aspirates showed a reduced number of segmented neutrophils. The ninth patient had a moderately severe course and the bone marrow showed maturation arrest at the promyelocyte stage. Bone marrow cultures demonstrated that the in vitro neutrophil colony formation and production of colony-stimulating activity were normal in all of the eight patients studied. Neutrophils from one of the nine patients had ultrastructural abnormalities such as decrease in number of primary and secondary granules and the presence of myelin figures in primary granules. Neutrophil chemotaxis was defective in three of the nine patients. All of the six patients in whom the neutrophil colony formation in agar, the ultrastructure of neutrophils, and neutrophil chemotaxis were normal recovered from the neutropenia between 11 and 30 months of age. These in vitro parameters appear to be useful for evaluating chronic neutropenia of childhood.

Phagocytosis of neutrophils by marrow macrophages in childhood chronic benign neutropenia

Chronic benign neutropenia of childhood is a heterogeneous disorder. This study describes two severely neutropenic children with a benign clinical course and the unique bone marrow finding of macrophage engulfment of band and segmented neutrophils. Phagocytic vacuoles in the majority of macrophages contained neutrophils in various stages of digestion at both the light and electron microscope level (with as many as four neutrophils observed in single macrophages). Ultrastructural studies demonstrated that the neutrophils were morphologically normal, and apparently viable at the time of phagocytosis. This type of neutrophil phagocytosis was not observed in five other consecutively studied children with CBN. All of these children with CBN had ultrastructurally normal neutrophils, lacked demonstrable antineutrophil antibodies or serum inhibitors to in vitro myelopoiesis, and had normal colony-forming cells and colony-stimulating activity in vitro. Thus despite many similar clinical and laboratory features in children with CBN, only a unique subgroup of these patients demonstrates abnormal neutrophil-macrophage interaction.

Neutrophil kinetics in hereditary and congenital neutropenias

Neutrophil production and distribution were studied in two families with autosomal dominantly inherited neutropenia to distinguish their illness from other neutropenic disorders. In addition to a reduced post-mitotic pool of bone-marrow neutrophils and neutrophil precursors, mitotic pool size was also reduced, ranging from 1.1 to 2.9 X 10(9) cells per kilogram (normal, 3.8 +/- 0.4 X 10(9) per kilogram). In vitro committed stem cells were reduced as well, ranging from 2 to 12/10(5) marrow cells (normal, 30 to 120/10(5)). In three patients neutrophil counts were observed to return to normal when they were adults. In one such subject studied, however, both the mitotic pool of neutrophil precursors and marrow committed stem cells were reduced. These abnormalities were in contrast to studies of a patient with chronic benign neutropenia of childhood and an infant with Kostmann-type congenital neutropenia, both of whom had increased marrow committed stem cells. These studies demonstrate several different mechanisms for production of neutropenia in these syndromes.

Chronic neutropenia in childhood. Analysis of 16 cases and a review of the literature

We analyzed the clinical histories and hematologic information concerning 16 persons in whom chronic neutropenia was discovered early in life. Only two of them, those with the lowest mean neutrophil counts, had frequent and severe pyogenic infections. Almost all the infections were caused by Staphylococcus aureus or by enteric microorganisms and involved the skin, respiratory tract or gastrointestinal system. The prognosis in our subjects or in patients described in the literature could not be predicted from the bone marrow morphology, presence or absence of blood monocytosis, pattern of genetic transmission or results of special tests of neutrophil function. We propose that the complex nomenclature associated with chronic neutropenic states be discarded until a better basis for classification becomes available.

[Constitutional familial leucocytopenia with partial Pelger anomaly and delayed development of bone (author's transl)]

The clinical and hematological findings in 4 boys of a family with a chronic constitutional leukocytopenia are described. Possible X-chromosomal sex-linked genetic transmission, the benign clinical course as well as the association with clinical and cytological hints of the involvement of the lymphatic cellular immunological system suggest a disease of its own. It was classified as a mild form of myelolymphatic insufficiency similar to reticular dysgenesis. The significance of Pelger-Huët anomalies of neutrophils demonstrated in the blood of the mother and of Pelger-like forms in the blood of children are discussed.