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

Rapid cell senescence and apoptosis in lymphocytes and granulocytes and absence of GM-CSF receptor in congenital dysgranulopoietic neutropenia

A girl with congenital dysgranulopoietic neutropenia (CDN) and her non-neutropenic mother with aphthae (A) were investigated. Apoptosis in lymphocytes and granulocytes of both patients (mother A+) were documented by high annexin and electron microscopic morphology. CD11b/CD18 of the daughter's granulocytes ranged between low to normal while that of the mother changed between very low to high levels through A(-) to A(+) periods. In both patients, CD11b/CD18 on lymphocytes were high; GM-CSF receptor was negative; CD4-/CD8- lymphocytes were high and the leukocytes which showed abnormal cell cycle were stained by senescence associated beta-galactosidase. We think that increased apoptosis and rapid cell senescence of leukocytes underlies the pathophysiology of CDN.

Leukemia in severe congenital neutropenia: defective proteolysis suggests new pathways to malignancy and opportunities for therapy

Severe congenital neutropenia (SCN), a heterogeneous disorder that includes Kostmann syndrome, predisposes to myelodysplasia and acute myelogenous leukemia. Recently identified heterozygous mutations in the gene ELA2, encoding neutrophil elastase on human chromosome 19pter, account for the majority of autosomal dominant cases of SCN, including those demonstrating neoplastic progression. The involvement of the serine protease neutrophil elastase, localized to the granules of neutrophils and monocytes, implies an unexpected role for proteolytic regulation of hematopoiesis. Continued elucidation of the clinical features, molecular genetics, and biochemistry is likely to provide insight into novel pathways of leukemia induction with attendant prospects for new avenues of therapy.

Genetics, phenotype, and natural history of autosomal dominant cyclic hematopoiesis

Cyclic hematopoiesis, (CH, or cyclic neutropenia) is a rare disease manifested by transient severe neutropenia that recurs approximately every 21 days. The hematologic profile of families with the autosomal dominant form (ADCH) has not been well characterized, and it is unknown if the phenotype is distinct from the more common sporadic congenital or acquired forms of CH. We studied nine ADCH families whose children displayed typical CH blood patterns. Pedigrees confirmed dominant inheritance without evidence of heterogeneity or decreased penetrance; three pedigrees suggested new mutations. Families were Caucasian with exception of one with a Cherokee Native American founder: A wide spectrum of symptom severity, ranging from asymptomatic to life-threatening illness, was observed within families. The phenotype changed with age. Children displayed typical neutrophil cycles with symptoms of mucosal ulceration, lymphadenopathy, and infections. Adults often had fewer and milder chronic neutropenia without distinct cycles. While CH is commonly described as "benign", four children in three of the nine families died of Clostridium or E. coli colitis, documenting the need for urgent evaluation of abdominal pain. Misdiagnosis with other neutropenias was common but can be avoided by serial blood counts in index cases. Genetic counseling requires specific histories and complete blood counts in relatives at risk to assess status regardless of symptoms, especially to determine individuals with new mutations. We propose diagnostic criteria for ADCH in affected children and adults. Recombinant human granulocyte colony-stimulating factor treatment resulted in dramatic improvement of neutropenia and morbidity. The differential diagnosis from other forms of familial neutropenia is reviewed.

Prenatal diagnosis of congenital dysgranulopoietic neutropenia

Congenital dysgranulopoietic neutropenia is a severe life-threatening disease characterized by specific dysmorphic granulocytes. Prenatal diagnosis of congenital neutropenia was reported first in 1983. In 1989 we reported a family with congenital dysgranulopoietic neutropenia in two siblings (one male and one female); in 1992 the mother became pregnant and prenatal diagnosis was performed by cordocentesis. The results we obtained from the fetus at risk enabled us to suggest that it was not affected, and we advised the parents that the pregnancy could continue: a healthy female was born. The neutrophil count at 2 and 4 months was normal.

Dyshematopoiesis in combined immune deficiency with congenital neutropenia

This report describes a patient with combined immune deficiency associated with congenital neutropenia (CID/CN) and reports a partial characterization of his hematopoietic abnormalities. The CID/CN syndrome described is characterized by neutropenia and by deficiencies in B-lymphoid and T-lymphoid cell number and function. Red cell and platelet counts were normal. In vitro assays indicate that the myeloid lineage was developmentally arrested at the level of the committed monocyte/granulocyte progenitor (CFU-GM), while precursors to the CFU-GM progenitor were normal. In vitro studies showed that the defect in myeloid development was not corrected with G-CSF or GM-CSF. However, combinations of cytokines present in conditioned media from the T-cell lines MO or C5MJ, or defined multiple cytokine combinations containing IL-1, IL-3, GM-CSF, kit ligand, IL-6, and IL-9, restored myelopoiesis in-vitro. In contrast, C5MJ-conditioned media did not correct deficiencies in immune function in the patient's lymphocytes and accessory cells. No abnormalities in the production of G-CSF, GM-CSF, M-CSF, or IL-1 from the patient could be identified to account for the defects in myelopoiesis orimmune function.