Cerebrovascular accidents in sickle cell disease: rates and risk factors.

Cerebrovascular accident (CVA) is a major complication of sickle cell disease. The incidence and mortality of and risk factors for CVA in sickle cell disease patients in the United States have been reported only in small patient samples. The Cooperative Study of Sickle Cell Disease collected clinical data on 4,082 sickle cell disease patients enrolled from 1978 to 1988. Patients were followed for an average of 5.2 +/- 2.0 years. Age-specific prevalence and incidence rates of CVA in patients with the common genotypes of sickle cell disease were determined, and the effects of hematologic and clinical events on the risk of CVA were analyzed. The highest rates of prevalence of CVA (4.01%) and incidence (0.61 per 100 patient-years) were in sickle cell anemia (SS) patients, but CVA occurred in all common genotypes. The incidence of infarctive CVA was lowest in SS patients 20 to 29 years of age and higher in children and older patients. Conversely, the incidence of hemorrhagic stroke in SS patients was highest among patients aged 20 to 29 years. Across all ages the mortality rate was 26% in the 2 weeks after hemorrhagic stroke. No deaths occurred after infarctive stroke. Risk factors for infarctive stroke included prior transient ischemic attack, low steady-state hemoglobin concentration and rate of and recent episode of acute chest syndrome, and elevated systolic blood pressure. Hemorrhagic stroke was associated with low steady-state hemoglobin and high leukocyte count.

Further evidence for the existence of a clonal Ph-negative stage in some cases of Ph-positive chronic myelocytic leukemia.

The Ph chromosome abnormality is involved in the pathogenesis of almost all patients with chronic myelocytic leukemia (CML). Previous studies on the B-lymphoid cell lineage in two patients with Ph-positive CML suggest that there may also be a clonal Ph-negative stage in CML and that the Ph-positive stage arises by subclonal expansion. To determine whether this is a frequent or a rare occurrence, 14 additional glucose-6-phosphate dehydrogenase (G6PD)-heterozygous patients with CML were studied. In five of these patients there was a statistically significant excess of Ph-negative B-lymphoid cell lines expressing the same G6PD type expressed in the corresponding CML clone. In no case was an excess of B-lymphoid lines expressing the opposite G6PD type recovered. These data provide further evidence that in some patients the Ph chromosome arises in a pluripotent stem cell from a pre-existing Ph-negative clone that enjoys a growth advantage.

Osteonecrosis of the humeral head in sickle cell disease.

The prevalence and incidence of osteonecrosis (ON) of the humeral head in sickle cell disease was determined by a study of 2524 patients who were entered into a prospective study and followed for an average of 5.6 years. At entry, 5.6% had roentgenographic evidence of ON in one or both shoulders. There was little difference in age-adjusted prevalence among genotypes, but there were striking differences in age-specific rates. Observed at ages ranging from five to 24 years, 3.25% of sickle cell anemia (S/S) patients, but only 1.1% of sickle cell disease (S/C) patients, had ON. No S/beta+ thalassemia patients younger than 25 years of age had ON on entry. The highest age-adjusted incidence rate was found in S/S patients with concomitant alpha-thalassemia (4.85 per hundred patient-years), followed by S/beta zero-thalassemia (4.84 per hundred patient-years), S/beta+ thalassemia (2.61 per hundred patient-years), S/S without alpha-thalassemia (2.54 per hundred patient-years), and S/C (1.66 per hundred patient-years). Only 20.9% of patients reported pain or had limited range of movement at the time of diagnosis. Sickle cell disease is a frequent cause of ON of the humeral head, especially in children and young adults.

Sickle cell disease as a cause of osteonecrosis of the femoral head.

BACKGROUND AND METHODS: Osteonecrosis of the femoral head is an important complication of sickle cell disease. We studied 2590 patients who were over 5 years of age at entry and followed them for an average of 5.6 years. Patients were examined twice a year, and radiographs of the hips were taken at least twice: at study entry and approximately three years later. RESULTS: At study entry, 9.8 percent of patients were found to have osteonecrosis of one or both femoral heads. On follow-up, patients with the hemoglobin SS genotype and alpha-thalassemia were at the greatest risk for osteonecrosis (age-adjusted incidence rate, 4.5 cases per 100 patient-years, as compared with 2.4 in patients with the hemoglobin SS genotype without alpha-thalassemia and 1.9 in those with the hemoglobin SC genotype). Although the rate of osteonecrosis in patients with the hemoglobin SC genotype did not differ significantly from that in patients with the hemoglobin SS genotype without alpha-thalassemia, osteonecrosis tended to develop in these patients later in life. Intermediate rates of osteonecrosis were observed among patients with the hemoglobin S-beta zero-thalassemia and the hemoglobin S-beta(+)-thalassemia genotypes (3.6 and 3.3 cases per 100 patient-years, respectively). Osteonecrosis was found in patients as young as five years old (1.8 cases per 100 patient-years for all genotypes). The frequency of painful crises and the hematocrit were positively associated with osteonecrosis. The mean corpuscular volume and serum aspartate aminotransferase level were negatively associated. Twenty-seven patients had hip arthroplasty during the study; 10 were under 25 years of age. Five of the 27 required reoperation 11 to 53 months after the initial operation. CONCLUSIONS: Osteonecrosis of the femoral head is common in patients with sickle cell disease, with an incidence ranging from about 2 to 4.5 cases per 100 patient-years. Patients with the hemoglobin SS genotype and alpha-thalassemia and those with frequent painful crises are at highest risk. The overall prevalence is about 10 percent. The results of hip arthroplasty are poor.

Evidence for clonal development of Wilms' tumor.

To assess the clonality of Wilms' tumor, glucose-6-phosphate dehydrogenase (G6PD) enzymes were studied in normal and tumor tissue from 11 black girls who were heterozygous for G6PD. Normal tissues expressed both A and B type G6PD, whereas only a single G6PD enzyme was found in all tumor specimens. These data support the clonal nature of Wilms' tumor. In the one patient with bilateral disease, type B G6PD was found in both a recurrence and a subsequent tumor in the contralateral kidney. This finding is consistent with either the chance occurrence of the same G6PD in independent tumors or persistence of the original malignant clone. Another patient, who presented with the nephroblastomatosis complex (a precursor of Wilms' tumor), also had only type B enzyme detected. Further studies in patients with bilateral disease or the nephroblastomatosis complex, including the use of molecular biologic probes, are needed to test the hypothesis that Wilms' tumor in these cases arises from a somatic mutation as a second event in persons with an underlying genetic alteration.

Transfusion and alloimmunization in sickle cell disease. The Cooperative Study of Sickle Cell Disease.

In 1,814 patients with sickle cell disease who had been transfused, the overall rate of alloimmunization to erythrocyte antigens was 18.6%. The rate of alloimmunization in this group appears to be an explicit function of the number of transfusions received because it increases exponentially with increasing numbers of transfusions. Alloimmunization usually occurred with less than 15 transfusions, although the rate of alloimmunization continued to increase when more transfusions were given. The rate of alloimmunization was less in patients with hemoglobin SC disease and sickle-beta+ thalassemia because these patients had received fewer transfusions. Children less than 10 years old had a slightly lower rate of alloimmunization than patients in other age groups even after correction for the number of transfusions given. Women were more frequently alloimmunized than men; this was largely due to the fact that women received more transfusions than men, but in the age group 16 to 20 years the increase may have been due in part to alloimmunization owing to pregnancy. Forty-five percent of those alloimmunized made antibodies of only one specificity; 17% made four or more antibodies reacting with different antigens. Antibodies to the C and E antigens of the Rh group, the Kell antigen, and the Lewis antigens were most commonly made. These findings may be important in formulating a rational transfusion policy in sickle cell disease.

Acyclovir-resistant varicella zoster virus infection after chronic oral acyclovir therapy in patients with the acquired immunodeficiency syndrome (AIDS).

Four patients with human immunodeficiency virus (HIV) infection who received chronic oral acyclovir therapy for suppression of recurrent varicella zoster or herpes simplex virus infection developed persistent disseminated hyperkeratotic papules that failed to heal with intravenous or high-dose oral acyclovir therapy. Varicella zoster virus, resistant to acyclovir in vitro, was isolated from skin lesions of all four patients. Three patients were adults in whom the acquired immunodeficiency syndrome (AIDS) had been diagnosed 12 to 20 months before isolation of acyclovir-resistant varicella zoster virus. The fourth patient was a perinatally HIV-infected child who developed primary varicella infection at age 7 years when profoundly immunosuppressed (absolute CD4+ lymphocyte count less than 50 cells/microL). Mean antiviral susceptibilities (ED50 values) of the four clinical isolates compared with the ED50 values of the reference strain Oka were 85 compared with 3.3 mumol/L for acyclovir, 1.4 compared with 0.8 mumol/L for vidarabine, and 123 compared with 117 mumol/L for foscarnet. When assayed by [125I]-dC plaque autoradiography, 90% to 100% of the viral isolate populations had altered or no measurable thymidine kinase function. Acyclovir-resistant varicella zoster virus infection may complicate long-term oral acyclovir administration in patients with AIDS and may be associated with the appearance of atypical hyperkeratotic papules.

Evidence for clonal development of childhood acute lymphoblastic leukemia.

To determine whether acute lymphoblastic leukemia (ALL) is a clonal disease and to define the pattern of differentiation shown by the involved progenitor cells, we studied the glucose-6-phosphate dehydrogenase (G6PD) types in the cells of 19 girls heterozygous for this X chromosome-linked enzyme. Lymphoblast immunophenotypes were those of HLA-DR+, CALLA+ ALL (six patients); HLA-DR+, CALLA- ALL (four patients); pre-B cell ALL (two patients); T cell ALL (four patients); and undefined ALL (three patients). Malignant blast cells at diagnosis from ten patients displayed a single G6PD type, indicative of clonal disease. In contrast, both A and B G6PD in ratios similar to those found in skin were observed in morphologically normal blood cells from the same patients. The leukemic cells of three patients were examined at both diagnosis and relapse; in each instance the same G6PD type was found, consistent with regrowth of the original leukemic clone at relapse. Results of studies of cells from nine additional patients tested only at relapse were similar. Our results indicate that childhood ALL is a clonally derived disease involving progenitor cells with differentiation expression detected only in the lymphoid lineage.

Cerebral blood flow in sickle cell cerebrovascular disease.

Cerebral blood flow (CBF) has been studied by the xenon-133 (133Xe) inhalation method in 16 children with suspected sickle cell cerebrovascular disease. Abnormalities consisting of decreases in total, hemispheral, or regional CBF were found in 17 of 26 studies. Eleven studies performed immediately after stroke, transient ischemic attack, or depression of state of alertness showed abnormalities. In addition to confirming regional cerebrovascular insufficiency in children with stroke due to major cerebral artery occlusion, the method detected diffuse decrease in CBF in children with stupor, coma, and seizures who had normal angiographic findings. In contrast, six of seven studies obtained after exchange transfusion or during maintenance on hypertransfusion therapy showed normal findings. The difference between results in patients with acute neurologic disturbances and those receiving transfusion therapy was statistically significant (P less than .005). The data indicate that the 133Xe method reliably demonstrates cerebrovascular impairment in sickle cell disease. They also suggest that CBF changes in patients with sickle cell disease can be reversed by exchange transfusion and by hypertransfusion therapy. The 133Xe CBF method may be useful for following up children with sickle cell disease who are at high risk for recurrent stroke.

Evidence for a stem cell common to hematopoiesis and its in vitro microenvironment: studies of patients with clonal hematopoietic neoplasia.

The origin and nature of cells forming the in vitro microenvironment in long-term cultures of human marrow were studied in five patients with clonal myeloproliferative disorders who were heterozygous for glucose-6-phosphatase dehydrogenase (G6PD). The results showed that cells in the adherent stromal layer forming the in vitro microenvironment were derived from the same clonal progenitors involved by the neoplasm in the four patients whose diseases originated in multipotent stem cells. In contrast, stromal cells were derived from normal progenitors in a patient with acute non-lymphocytic leukemia whose clone showed differentiative expression confined to cells in the granulocytic lineage. Mixing experiments demonstrated that the G6PD type displayed by the adherent marrow stromal cells was not obscured by contaminating non-adherent hematopoietic cells or marrow fibroblasts. The data suggest the existence of a pluripotent cell in normal hematopoiesis that gives rise to hematopoietic cells and to their micro-environment.

Further chromosome studies on Wilms' tumor cells of patients without aniridia.

We studied chromosomes in Wilms' tumor cells of two patients without aniridia who had a normal constitutional karyotype. In both tumors, trisomy for 1q occurred as the result of a t(1;16), although the breakpoints in each chromosome differed in the two tumors. No 11p rearrangements could be detected, whereas in our previous patient an interstitial deletion of 11p13 was present in all tumor cells. Thus, trisomy for 1q may be another pathway leading to the development of Wilms' tumor, although the effect of the deletion of 16q cannot be assessed at present.

Chromosome pattern in childhood acute nonlymphocytic leukemia (ANLL).

We studied the karyotype in 26 children with ANLL, which was diagnosed on the basis of the FAB classification. Clonal chromosome abnormalities were found in 21 of 26 patients. Four patients, including 3 with Down's syndrome, had AML(M1). Nine patients, including 3 with t(8;21), had AML(M2). All 3 patients with APL(M3) had t(15;17). Four patients had AMMOL(M4); 3 of these had a normal karyotype. Six patients had AMOL(M5); 5 and 11q rearrangements, and 3 of these had a break in 11q23. Only one patient had EL(M6), and he had a normal karyotype. One patient with t(11;19), classified as AML(M2) on Wright-Giemsa-stained cells, had a strong alpha-naphthyl acetate esterase reaction, indicating that the leukemic cells had a cytochemical feature characteristic of monocytes. Whereas t(8;21) and t(15;17) are uniquely associated with AML(M2) and APL(M3), respectively, the 11q rearrangements are also seen in AML(M1/M2), although they are more common in AMOL(M5) and AMMOL(M4). The case with t(11;19) suggests that cells with 11q rearrangements and with AML(M1/M2) may have both monocytic and granulocytic features. When we used our data and previous reports on 243 aneuploid patients (169 adults and 74 children) to correlate the chromosome abnormalities with patient age, we found differences in the chromosome pattern seen among various age groups. This suggests that different etiologic factors as well as changes in host susceptibility may influence the development of and the karyotypic pattern in the various types of leukemia. Moreover, the frequency of various chromosome abnormalities in childhood ANLL can provide a baseline for comparison of the frequency of the same abnormality in adults. The karyotypic analysis of childhood ANLL is important not only because of the information that can be obtained about childhood ANLL, but also because the data can provide substantial insight into the etiology of ANLL in adults.

Chromosome abnormalities in Down's syndrome patients with acute leukemia.

Chromosome and cytologic studies were performed on three Down's syndrome (DS) patients with acute nonlymphocytic leukemia (ANLL). All three patients had an aneuploid clone in their leukemic cells: 50, XX, +6, +19, +21, +22, +8, XX, +21, and 47,XY, +8, - 21 +dic(21;21)(p13;p11). Every patient appeared to have acute undifferentiated leukemia when the blast cells were examined with Wright-Giemsa stain; cytochemistry studies, however, showed that the leukemic blasts were in an early stage of myeloid differentiation. The two patients with +8 had a preleukemic phase; the blast cells of the patient with an extra no. 19 and no.22 could not be differentiated morphologically from those of the two patients with an extra no. 8. Our findings and a review of data on 40 other patients suggest that most DS children with ANLL have hyperdiploidy, which is usually related to gains of C, F, and /or G chromosomes, and that the abnormalities of +8 and of +19, +22 in DS children may be associated with acute leukemia (AL) in an early stage of myeloid differentiation.

Acute nonlymphocytic leukemia: heterogeneity of stem cell origin.

Four patients with acute nonlymphocytic leukemia who were heterozygous for the X-chromosome-linked enzyme glucose-6-phosphate dehydrogenase (G6PD) were studied to determine the numbers and types of progenitor cells in which the disease arose. Both forms of enzyme were found in normal tissues, but the malignant blast cells showed only one G6PD, indicating that the disease was clonal at the time of testing. The observations that normal erythroid cells were present in two young patients at diagnosis and relapse indicate that the clone suppressed expression of normal granulopoiesis but did not prevent normal erythroid differentiation. In contrast to this situation, in two elderly patients, the disease involved stem cells multipotent for granulocytes, red cells, and platelets. These results indicate that acute nonlymphocytic leukemia is heterogeneous. In some patients, the disease is expressed in cells with differentiation restricted to the granulocyte-monocyte pathway; in others, it involves stem cells capable of differentiating to granulocytes-monocytes, platelets, and erythrocytes. This heterogeneity may reflect differences in causation and could have prognostic and therapeutic importance.

The 14q+ chromosome in pre-B-ALL.

A child who had acute lymphoblastic leukemia (ALL) associated with an 8;14 chromosome translocation and with a pre-B phenotype is described. The leukemic cells were determined to be pre-B-cells on the basis of intracytoplasmic mu-chain immunoglobulin (cIgM+) and the common-ALL antigen, lack of receptors for sheep erythrocytes, and lack of surface immunoglobulin. The 8;14 translocation is frequently found in patients with Burkitt's lymphoma and in most patients with B-cell ALL and is known to carry a poor prognosis. Thus far, no karyotypes have been reported for patients with pre-B-ALL. The present case indicates that a 14q+ chromosome may provide a proliferative advantage not only to cells with a B-cell phenotype, but also to pre-B-cells. The short survival of our patient also suggests that the 14q+ abnormality and the pre-B phenotype may signal a poor prognosis.

Gallium scan as a prognostic indicator in neuroblastoma.

Gallium-67 scan results were correlated with the long-term clinical course in ten children with neuroblastoma. The four patients whose primary tumor did not accumulate gallium have exhibited a significantly better survival time (mean duration 68.2 months) as compared to the six patients with gallium-positive tumors (mean duration 16.6 months, P < 0.001). This difference in survival was not explainable on the basis of accepted prognostic indicators, such as age of patient or stage of disease at initial diagnosis. These results indicate that gallium uptake may be a useful prognostic indicator in children with neuroblastoma, independent of other variables.

Acute nonlymphocytic leukemia: expression in cells restricted to granulocytic and monocytic differentiation.

Two patients with acute nonlymphocytic leukemia who were heterozygous for the X-chromosome-linked enzyme glucose-6-phosphate dehydrogenase were studied to determine the number and type of cells in which the disease arises. Both type A and B isoenzymes were found in normal tissues, but the myeloblasts showed only one enzyme type, indicating that at the time of study, the disease had a clonal origin. The observation in one patient that erythroid cells did not arise from this clone contrasts with conclusions reached in patients previously studied with chromosomal markers. The results suggest that in this patient, the leukemic clone suppressed expression of normal granulopoiesis but did not inhibit erythroid differentiation from normal progenitors. They suggest also that the disease is heterogeneous. In some patients, the disease is expressed in cells with differentiation restricted to the granulocyte-macrophage pathway; in others, it involves stem cells that also differentiate into erythrocytes. This heterogeneity may reflect differences in causation and could have prognostic importance.

Childhood leukemia presenting as a diaphyseal radiolucency.

A 41-month-old black child with a symtomatic diaphyseal destructive lesion of the femur, and a corresponding area of increased uptake on a technetium99m bone scan, had an upper respiratory tract infection. An open biopsy was performed because of an initial clinical diagnosis of osteomyelitis, histiocytosis X or a round cell sarcoma. The biopsy showed numerous blast cells compatible with acute lymphocytic leukemia. Acute leukemia should be included in the differential diagnosis of symptomatic diaphyseal destructive lesions in children. A peripheral blood smear should be carefully interpreted prior to any other invasive diagnostic tests.

Scintigraphic evaluation of childhood malignancies by 67Ga-citrate.

The utility and limitations of 67Ga scintigraphy in children with solid tumors were evaluated. Thirty-five patients with malignancies (13 lymphoreticular neoplasms, 11 soft-tissue sarcomas, 8 neuroblastomas, and 3 primary bone tumors) had a 67Ga-citrate scan as part of their clinical evaluation. The sensitivity and specificity of the test were analyzed for the different tumor types. The overall sensitivity of the 67Ga-citrate scan for the lymphoma group was 87%. Higher values were obtained for the mediastinal and abdominal regions. Ninety-three per cent of the involved sites were correctly identified by 67Ga scintigraphy in the soft-tissue sarcoma group. Small lung metastases, however, were missed on scan. Thus, 67Ga scans should be complemented with chest radiographs and whole chest tomograms for both initial evaluation and follow-up in those patients. 67Ga had low sensitivity for neuroblastoma.