Intracranial calcification after cord blood neonatal transplantation for krabbe disease.

Infantile-onset Krabbe disease results from a deficiency of the lysosomal enzyme galactocerebrosidase and leads to death from profound central and peripheral demyelination. Neonatal hematopoietic cell transplantation may result in near-normal cognitive development and partial rescue of gross motor development. The long-term course of the disorder for treated patients seems to involve slowly progressive neurological impairment. We describe the detailed 3-year outcomes of this experimental procedure using umbilical cord blood in a prenatally-diagnosed newborn with Krabbe disease. Substantial perivascular calcifications and atrophy of the white matter developed in the first year post-transplantation. Despite persistent neuroradiological and electrophysiological evidence of leukodystrophy, at age 3 years she has had only mildly impaired non-motor development and moderately impaired motor skills. The cause of these severe white matter changes may have been due to ongoing Krabbe disease or to effects of the chemotherapy regimen or to an interaction of these factors. Extended long-term follow-up of children neonatally transplanted for Krabbe disease is needed before the full utility and limitations of neonatal transplantation can be determined.

Ictal and interictal technetium-99m-bicisate brain SPECT in children with refractory epilepsy.

UNLABELLED: Identification of epileptogenic foci in patients with refractory epilepsy remains a significant diagnostic challenge. Magnetic resonance imaging studies frequently fail to reveal an anatomic origin for the seizures, and scalp electroencephalography is often limited to identification of the involved hemisphere. Functional imaging modalities such as PET and SPECT are more promising tools for this application because they reflect the functional pathology associated with the seizure. These changes are more pronounced ictally, but until recently, no radiopharmaceutical was available that could be used routinely for ictal SPECT. The present study was therefore undertaken to determine whether 99mTc-bicisate could be used in ictal SPECT in pediatric patients with refractory epilepsy, to compare the patterns of ictal and interictal blood flow in these patients and to compare the localization information provided by ictal SPECT with that available from other techniques. METHODS: Technetium-99m-bicisate/SPECT was compared prospectively with scalp EEG for its ability to identify a possible seizure focus in pediatric patients with refractory epilepsy. Ictal and interictal SPECT studies were performed in 10 patients (3-19 yr old, mean age 10.9 +/- 4.3 yr; 7 female, 3 male) in whom MRI scans revealed no lesions that might be responsible for the seizures. RESULTS: Ictal SPECT was performed in all patients, and all ictal studies revealed focal perfusion abnormalities. By comparison, four of the interictal SPECT studies showed regional hypoperfusion that corresponded to the regions of hyperperfusion in the ictal studies, and three showed regional hyperperfusion corresponding to the hyperperfused regions in the ictal studies. Three interictal studies revealed no abnormal perfusion. Scalp EEG provided localization information in five patients. CONCLUSION: These initial results suggest that ictal SPECT with 99mTc-bicisate is a more promising tool for the identification of epileptogenic foci than interictal SPECT or scalp EEG in patients without focal abnormalities on MRI.

Treatment of acute myeloid leukemia cells in vitro with a monoclonal antibody recognizing a myeloid differentiation antigen allows normal progenitor cells to be expressed.

Monoclonal antibody L4F3 reacts with most acute myeloid leukemia (AML) cells and virtually all normal granulocyte/monocyte colony-forming cells (CFU-GM). Our objective was to determine whether lysis of AML cells with L4F3 and complement allowed expression of normal myeloid progenitors. The five glucose-6-phosphate dehydrogenase (G6PD) heterozygous patients with AML studied manifested only a single G6PD type in blast cells and in most or all granulocyte colony-forming cells, indicating that the leukemias developed clonally. The cells remaining after L4F3 treatment from two of the patients gave rise to granulocytic colonies that expressed the G6PD type not seen in the leukemic clone, indicating that they were derived from normal progenitors (CFU-GM). L4F3-treated cells from these two patients cultured over an irradiated adherent cell layer from normal long-term marrow cultures also gave rise to CFU-GM, which were shown by G6PD analysis to be predominantly nonleukemic. In the other three patients, the progenitor cells remaining after L4F3 treatment were derived mainly from the leukemic clone. The data suggest that in vitro cytolytic treatment with L4F3 of cells from certain patients with AML can enable normal, presumably highly immature progenitors to be expressed.

Human bone marrow stromal cell colonies: response to hydrocortisone and dependence on platelet-derived growth factor.

Long-term bone marrow cultures are dependent on the formation in vitro of an adherent cell layer that supports hematopoiesis. We have grown bone-marrow-adherent cells, termed stromal colony-forming units, or CFU-ST, as isolated adherent colonies, and examined some of their growth requirements. Bone marrow mononuclear cells separated from aspirates by density centrifugation and cultured in medium supplemented with fetal calf serum or human plasma gave rise to adherent colonies (CFU-ST). An average of 23.4 +/- 2.1 (mean +/- SEM, n = 19) CFU-ST were produced by 10(5) bone marrow mononuclear cells. CFU-ST could not be cultured from similarly prepared peripheral blood mononuclear cells. The colonies were composed of spindle cells, flat cells, and fat-containing cells, with all three types often present in the same colony, suggesting derivation from a common progenitor. Cells were negative for nonspecific esterase and factor VIII antigen. Hydrocortisone added to the cultures at concentrations of 10(-7) M induced the formation of adipose cells in the center of one-third to one-half of the colonies but did not affect CFU-ST number. Human platelet-poor plasma and platelet-rich plasma were substituted for fetal calf serum in the medium. When all determinations for four experiments were averaged, platelet-rich plasma gave 17.8 +/- 1.2 (mean +/- SEM, n = 16) colonies, whereas platelet-poor plasma gave only 0.2 +/- 0.1 colonies (n = 15). When purified platelet-derived growth factor (PDGF) was added to platelet-poor plasma, growth of CFU-ST was enhanced, and a dose-response relationship was found between size of colonies and concentration of added PDGF. Granulocyte-macrophage colony stimulating factor added to cultures had no effect on the growth of CFU-ST.

Differential effect of hydrocortisone on eosinophil and neutrophil proliferation.

Glucocorticosteroid therapy results in an increase in the number of circulating neutrophils and a decrease in the number of eosinophils. Utilizing the double layer soft agar technique, we examined the effect of physiologic to pharmacologic concentrations of hydrocortisone on the proliferation of human neutrophil progenitors and eosinophil progenitors from peripheral blood and bone marrow. When peripheral blood cultures were studied, eosinophil proliferation was inhibited in a dose-responsive fashion with 10(-8) - 10(-5) M hydrocortisone succinate, and comprised 49 +/- 4% of the colonies in control cultures and only 4 +/- 1% (P less than 0.01) at pharmacologic levels of hydrocortisone (10(-5) M). The number of neutrophil colonies, on the other hand, increased by 31% when 10(-5) M hydrocortisone was added to cultures. In order for corticosteroids to exert this effect, it was necessary to add them within 24 h of the initiation of culture. The effect of hydrocortisone on granulocyte proliferation could not be blocked by progesterone, a structurally analogous steroid. To determine whether hydrocortisone was acting directly on the progenitor cell or via an effector cell, its effect on modulating cell populations and stimulating-factor production was studied. Removal of E-rosetting cells and/or adherent cells did not affect the inhibition of eosinophil colony growth or the enhancement of neutrophil colony growth. Furthermore, addition of the potent inhibitor of T cell function, cyclosporin A, failed to affect eosinophil colony frequency, suggesting that inhibition of T cell function was an unlikely explanation for the observed hydrocortisone effect. Leukocyte conditioned media (LCM), derived from peripheral blood mononuclear cells incubated with hydrocortisone, was devoid of both neutrophil and eosinophil colony-stimulating activity, whereas a control LCM stimulated both neutrophil and eosinophil proliferation. The data suggest that the observed hydrocortisone effect on granulocyte colony formation is unlikely to be mediated by an intermediary, and that hydrocortisone acts directly on progenitor cells.

Heterogeneity of B cell involvement in acute nonlymphocytic leukemia.

In order to study the pattern of B cell involvement in acute nonlymphocytic leukemia (ANLL), multiple B lymphoid cell lines were established by Epstein-Barr virus transformation of peripheral blood mononuclear cells from two patients with the disease who were heterozygous for the X chromosome-linked glucose-6-phosphate dehydrogenase (G6PD). In one patient, the progenitor cells involved by the leukemia exhibited multipotent differentiative expression, whereas in the other patient the cells showed differentiative expression restricted to the granulocytic pathway. In the patient whose abnormal clone showed multipotent expression, the ratio of B-A G6PD in B lymphoid cell lines was skewed in the direction of type B (the enzyme characteristic of the leukemia clone) and significantly different from the 1:1 ratio expected. It is, therefore, likely that the neoplastic event occurred in a stem cell common to the lymphoid series as well as to the myeloid series. In contrast, evidence for B cell involvement was not detected in the patient whose ANLL progenitor cells exhibited restricted differentiative expression. These findings underscore the heterogeneity of ANLL. Clinically and morphologically similar malignancies in these two patients originated in progenitors with different patterns of stem cell differentiative expression. This difference may reflect differences in cause and pathogenesis.

Inhibition of CFU-NM and CFU-EOS by mature granulocytes.

Approximately half of the colony-forming units-culture (CFU-C) from normal peripheral blood are eosinophilic. The purpose of our study was to determine: (1) whether progenitor cells committed to eosinophil or neutrophil maturation would be differentially affected by feedback inhibition, and (2) whether mature eosinophils added to the feeder layers of the culture would inhibit the proliferation of CFU-C in a manner similar to that described for neutrophils. Concentrated eosinophils and neutrophils, obtained by separation on a metrizamide gradient, were added to feeder layers containing either 10(6) autologous whole mononuclear cells (WMNC) or 0.1 ml of leukocyte conditioned media (LCM). The average number of colonies was 123/10(6) nonadherent cells (NAC) cultured. When neutrophils or eosinophils were added to the WMNC feeder layer, the percent inhibition of growth was 40.2% +/- 1.6% (mean +/- SEM) and 42.3% +/- 5.4%, respectively, but the ratio of neutrophil to eosinophil colonies remained constant. No effect was seen when neutrophils or eosinophils were added to an LCM feeder layer. Thus, it appears that the differential control of neutrophil versus eosinophil production in vitro is not regulated through feedback inhibition by mature granulocytes. In addition, these studies suggest that eosinophils, as well as neutrophils, cause inhibition of CFU-C growth when intact cells are the source of colony-stimulating factor (CSF).

Peripheral blood myeloid progenitor cell cultures in patients with hypereosinophilic syndrome (CFU-eos in hypereosinophilic syndrome).

Myeloid progenitor cell cultures (CFU-C) were established in a double-layer agar system with peripheral blood mononuclear cells from 13 patients with the hypereosinophilic syndrome (HES). Normal controls produced 49% +/- 3.5% eosinophil colonies; results in 7 of the 13 HES patients were within the normal range, while in 5, the proportion of eosinophil colonies was greater than 3 standard deviations above the normal mean, and in 1 patient there was a low proportion of eosinophil colonies. The production of an increased proportion of eosinophil colonies correlated with more aggressive disease. Experiments in which normal progenitor cells were cultured over feeder layers of mononuclear cells demonstrated that cells of 3 of the 5 patients had an excess production of eosinophil colony-stimulating activity. When HES patients progenitor cells were cultured over normal feeder layers, 2 of the 5 patient samples continued to produce an increased proportion of eosinophil colonies, suggesting that these patients have an excess proportion of progenitor cells committed to eosinophil differentiation. Thus, the results demonstrated heterogeneity of growth characteristics for the HES patients. None, however, had the colony growth characteristic of acute or chronic myelogenous leukemia.

NIH conference. The idiopathic hypereosinophilic syndrome. Clinical, pathophysiologic, and therapeutic considerations.

The idiopathic hypereosinophilic syndrome (HES) represents a heterogeneous group of disorders with the common features of prolonged eosinophilia of an undetectable cause and organ system dysfunction. Fifty patients with the idiopathic HES were studied over 11 years of the National Institutes of Health. Multiple organ systems were involved; bone marrow hypereosinophilia was common to all patients, but the most severe clinicopathologic involvement was of the heart and nervous system. Postmortem gross pathologic examination of the hearts of patients with idiopathic and nonidiopathic HES suggested that the common mechanism of cardiac disease is the eosinophilia. Endomyocardial biopsy findings showed that the endothelial cells in the endocardium and of the microvasculature were the primary targets of the tissue damage. This damage initiates thrombosis; endocardial fibrosis and restrictive endomyocardopathy may follow. In-vitro culture of circulating eosinophil colony-forming units showed some normal studies, some studies showing increased progenitor cells committed to eosinophil development, and others showing an excess production of eosinophil colony-stimulating factor. Chemotherapy to lower the eosinophil counts has resulted in marked improvement of HES prognosis, as have agressive medical and surgical approaches to cardiovascular complications.

In vitro culture of circulating CFUEOS from normal donors.

Using an accurate technique for staining and scoring soft agar cultures, this study defines the incidence of circulating CFUEOS in normal donors. With whole mononuclear cells as the source of colony stimulating factor (CSF) and fetal calf serum, 49.6% +/- 3.5 of the colonies were eosinophilic; with human placental conditioned media and fetal calf serum 33.2% +/- 12.9 of the colonies were eosinophilic, with AB serum and whole mononuclear cells in the feeder layer 58.6% +/- 9.1 of the colonies were eosinophilic. The percentage of mixed neutrophil/eosinophil colonies was similar under varying culture conditions suggesting the presence of circulating progenitor cells capable of producing both lines.