Comparative study of Fanconi anemia in children of different ethnic origin in South Africa.

A comparative study of clinical, hematologic, and cytogenetic findings was made in 40 black and 35 white children with Fanconi anemia. The black children were Bantu-speaking Negroid stock of diverse tribal origin. The white children were predominantly Afrikaans stock of Dutch/German/French Huguenot origin. All of the patients had IFAR scores of 2 to 4+ and over 80% in each group had increased spontaneous and/or mutagen-induced chromosomal breakage (CB-positive). There were no significant clinical differences between black and white patients or between CB-pos and CB-neg patients, with the exception of white children in whom significantly more CB-pos patients had thumb and radial anomalies than the CB-neg patients. The age-at-onset of hematologic manifestations was the same for all groups, but more black than white CB-pos patients were severely anemic at the time of diagnosis. Response to androgen and steroid therapy occurred in only 33% of black children compared with 86-90% of white children; 81% of black patients died during the 18 year study period compared with 30% of white children, but the age at death was similar. More sophisticated studies are required to determine whether these differences are genetically determined or related to cultural, educational, and socio-economic differences between the two ethnic groups.

Geographical distribution of acute lymphoblastic leukaemia subtypes: second report of the collaborative group study.

Childhood acute lymphoblastic leukemia (ALL) T and B precursor subtypes have been identified by standardised immunophenotyping in different geographic and ethnic settings. Comparison of the relative frequencies and estimated incidence rates of the major subtypes indicates very similar values, with the striking exception of black childhood populations in Africa in which there appears to be a significant and selective deficit in the incidence of the common (B-cell precursor) subset of ALL. There is suggestive evidence for a similar bias in ALL subtypes in South Africans of mixed ethnic origin and in Mapuche Indians from Chile. Several interpretations of these data are possible but the one favoured attributes these differences primarily to socio-economic factors and patterns of infection in infancy.

Pattern of 6-mercaptopurine urinary excretion in children with acute lymphoblastic leukemia: urinary assays as a measure of drug compliance.

A method for the measurement of 6-mercaptopurine (6MP) in urine using high-performance liquid chromatography is described. Urinary excretion of 6MP was measured in 46 children with acute lymphoblastic leukemia. The proportion of unchanged drug excreted after oral dosage in the morning was greater than after an evening dose (5.6 +/- 3.3% vs. 3.3 +/- 2.4%). Possible reasons for the discrepancy are discussed. In all children receiving 6MP in the morning, the drug was detected in urine at 2 and 4 h after ingestion. At 6 h, 6MP was still detectable in 77% of patients, at 8 h in 54%, at 10 h in 12%, and at 12 h in 8%. The reliability of urinary 6MP determination as a measure of drug compliance was assessed in 39 children accustomed to receiving their medication in the evening. 6MP was detected in 81% of first morning urine samples, indicating compliance with medication the preceding evening. The absence of 6MP in first morning urine samples did not necessarily indicate poor compliance because of the variability in 6MP excretion and unpredictable pattern of night voiding in children. The method was therefore a reliable measure of good short-term compliance. It also directed attention toward possible noncompliance in children with negative samples.

Fanconi anemia in black African children.

Fanconi anemia (FA) has rarely been reported in black children either in the United States or Africa. This report describes 25 black African children with FA seen in Johannesburg over an 11-year period. The prevalence of homozygotes was estimated to be 1:476,000. Clinical manifestations, mean age at diagnosis, and hematologic and chromosome abnormalities were similar to those described in other ethnic groups. Response to androgens was poor and most patients required regular transfusions. Seventeen (68%) of the children died during the 11-year observation period. Leukemia was the terminal event in 2 patients. The mean age at death was 9.8 years and the mean time between diagnosis and death 2.3 years. The poor response to androgens, high mortality, and early mean age at death would favor consideration of early bone marrow transplantation in these children.

Compliance with chemotherapy in childhood leukaemia in Africa.

Compliance with chemotherapy in childhood leukaemia is usually good because of parental fear of the disease. However, poor compliance and refusal of treatment have been reported from both the USA and the UK. Little is known about African concepts of leukaemia, attitudes to treatment or compliance. A study was undertaken to investigate factors which might affect compliance in 15 black and 30 white families of leukaemic children in Johannesburg. The socio-economic and educational status of the black families was lower than that of the white. Only 53% of black children attended hospital on the appointed day compared with 90% of white children. Less than 50% of black parents understood the nature of their child's illness. Both black and white families had unused medication at home. White parents more frequently reported toxic effects related to chemotherapy and more white children than black children exhibited lymphopenia during maintenance therapy. Assessment of drug compliance should be included as an independent variable when evaluating factors affecting response to chemotherapy in communities of diverse ethnic, socio-economic and cultural backgrounds.

Streptococcus bovis bacteraemia associated with candidal lesions of the large bowel in a leukaemic child. A case report.

A 5-year-old boy with acute myeloblastic leukaemia had large-bowel masses, demonstrated at autopsy, 5 weeks after an episode of Streptococcus bovis bacteraemia. The association of Strept. bovis bacteraemia with large-bowel disease, well documented in adults, should be considered in children.

Bone growth and haemopoiesis: steroid reversible anaemia, myelofibrosis and increased bone formation in a child.

Factors regulating the interaction between bone marrow haemopoietic cells, stromal elements and bone growth are poorly understood. Disturbance in the equilibrium between these elements can occur as the result of metabolic bone disease, haematologic disorders, neoplasia and infections. The present report concerns a child with myelofibrosis, hypoplastic/dyserythropoietic anaemia, osteoblast proliferation and increased bone formation. A positive tuberculin skin test and elevated EB virus titre indicated previous exposure to Mycobacterium tuberculosis and Epstein-Barr virus. No active focus of infection was identified and no improvement occurred following anti-tuberculous therapy. A dramatic improvement occurred on corticosteroid therapy. Reticulocytosis was followed by an increase in haemoglobin and platelets and a decrease in ESR. Bone marrow fibrosis resolved and the marrow was repopulated with normal haemopoietic tissue. The bone abnormalities improved both radiologically and histomorphometrically. Relapse occurred when steroids were discontinued. Bone marrow tissue culture supernate from the patient during the active phase of the disease inhibited colony formation by normal marrow mononuclear cells. This was reversed by steroid therapy. It is postulated that EB virus may have triggered osteoblast proliferation with resultant bony and haematologic changes. Response to corticosteroids could be explained on the basis of suppression of osteoblast activity and correction of fibroblast mediated suppression of haemopoiesis.

A unique 8;16 translocation in two infants with poorly differentiated monoblastic leukemia.

Acute monoblastic leukemia is nonrandomly associated with abnormalities involving 11q. Two infants, one a neonate and the other 19 months of age, had the same hitherto undescribed karyotypic abnormality, t(8;16)(p11;p13), associated with acute nonlymphocytic leukemia M5a. The older child had an additional translocation, t(10;11)(q11;p15), but the chromosome arms affected were the opposite to those described in acute nonlymphocytic leukemia M5a of childhood. Therefore, it is postulated that genes involved in monocytic differentiation may be situated on 8p11 or 16p13, as well as on 11q.

A survey of human T-cell leukaemia virus type I antibodies in patients with malignant disease in the Witwatersrand area.

The prevalence of antibodies to human T-cell leukaemia virus type I in Africa ranges from 2% to 21% according to the geographical area surveyed. Most studies suggest that the background infection rate in children is low. In paediatric patients with malignant disease in the Witwatersrand area the prevalence is low (1%), whereas a seemingly high rate is found in healthy black children from a restricted rural area (7%). Further, the antibody prevalence in adult whites with lymphoproliferative disease is low (1%) compared with that in blacks with malignant disease (6%). There also appears to be a higher prevalence of positive results in black women (7%) than in black men (4%).

Acute childhood leukemia in Johannesburg. Ethnic differences in incidence, cell type, and survival.

Acute childhood leukemia was found to be less common in black children than in white children in the Johannesburg area of South Africa. Of 195 consecutive patients, 78 were black and 117 white. The annual incidence was 0.8/100,000 black children and 3.3/100,000 white. The low incidence in black children was due to the very low incidence of acute lymphoblastic leukemia (ALL), which was 0.41/100,000 black children compared with 2.73/100,000 white children. The incidence of acute nonlymphoblastic leukemia (ANLL) was approximately the same for both ethnic groups; 0.38/100,000 black children and 0.57/100,000 white children. Remission rates for black children with ALL were lower than for white children and the cumulative proportion of black patients surviving at 60 months was only 32% compared with 72% of white patients (p = 0.0001). The most significant poor prognostic factors in ALL were ethnic group and age (p = 0.0006), CNS disease at onset (p = 0.006), FAB L2 and L3 morphology (p = 0.05), and irregular clinic attendance during maintenance therapy (p = 0.05). In ANLL, remission and survival rates were less favorable than in ALL but there were no significant differences between black and white patients. Black patients exhibited certain clinical features rarely seen in white patients, including chloromata, oropharyngeal lesions, and CNS involvement at onset. Karyotypic abnormalities were common. The most significant poor prognostic factors in ANLL were CNS disease at onset (p = 0.03), generalized lymphadenopathy (p = 0.0001), and FAB morphology classification M3-M6 (p = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Gaucher's disease in a black child in South Africa. A case report.

A 7-year-old Black boy presented with massive splenomegaly and a tendency to haemorrhage due to type 1 Gaucher's disease. After splenectomy he became asymptomatic and the haematological parameters returned to normal. Although type 1 Gaucher's disease has been described in adult Blacks, it has not been reported previously in a Black child in southern Africa.

Piroxicam poisoning in a 2-year-old child. A case report.

This report describes the severe multisystem toxicity which followed ingestion of 5 piroxicam capsules (100 mg) by a 2-year-old child. Gastro-intestinal symptoms developed within 2 hours, resulting in severe fluid and electrolyte imbalance, mental confusion and a generalized seizure. Evidence of liver and renal dysfunction developed within 3 days. Haemopoietic toxicity was manifested by progressive peripheral pancytopenia, bone marrow aplasia and coagulopathy. Pseudomonas septicaemia developed during the period of neutropenia. Clinical, biochemical and haematological abnormalities slowly resolved over 3-4 weeks. In view of the increasing use of piroxicam as an anti-inflammatory agent it seemed important to draw attention to the potentially serious effects of accidental overdosage.

Chromosome patterns in 26 South African children with acute nonlymphocytic leukemia (ANLL).

Of 46 black leukemic children 52% had acute nonlymphocytic leukemia (ANLL), whereas only 11% of 62 white leukemic children had the disease. An abnormal karyotype was found in 73% of the 26 children with ANLL, and the majority of abnormal karyotypes were pseudodiploid. "Balanced" translocations were noted in 10 children, of whom four had t(8;21) associated with M2 ANLL, two had t(15;17) and M3 ANLL, two had a t(9;22), one child with M5 ANLL had t(10p;11q), and an infant with congenital M5 ANLL had t(8;16). Monosomy #7 was detected in two preleukemic children who subsequently developed M4 ANLL. Hyperdiploidy was present in only three cases. These patterns were compared with those of other published series, confirming the increased frequency of chromosome abnormalities in children with ANLL. The differing ratio of ANLL:ALL, some of the distinctive clinical features, and the high frequency of detectable chromosome abnormalities in black children may be reflections of a particular oncogenic agent(s) within their environmental background that could be responsible for the initiation of the leukemic process.

Karyotype analysis in acute nonlymphocytic leukemia (ANLL): comparison with ethnic group, age, morphology, and survival.

The karyotype, leukemia cell morphology (FAB classification), ethnic group, age, sex, and survival were compared in 60 patients with acute nonlymphocytic leukemia (ANLL), to determine their diagnostic and prognostic significance. An ethnic age difference was observed; a significantly greater number of black patients were children. The majority of children were males. A higher frequency of chromosome abnormalities was detected in children, yet they survived longer than adults. A specific, significant association between a (8; 21) karyotype and M2-ANLL was confirmed; four of ten patients with M2-ANLL showed this translocation. The more mature morphology of M2-ANLL was associated with a longer survival irrespective of karyotype, ethnic group, and age. The specificity of t(15; 17) in M3-ANLL and nonrandom monosomy 7 in preleukemic children was confirmed. Patients, particularly adults, with normal karyotypes tended to survive longer than those with abnormal karyotypes. The patient's age and the differentiative capacity of the leukemic cell appear to be as important as the karyotype in determining survival. The nonrandom association of certain chromosome aberrations in ANLL appears to be worldwide.

Mechanisms of anemia in protein-energy malnutrition in Johannesburg.

Studies of red cell metabolism, erythropoeitin concentration, iron and folate status were made in 48 children with protein-energy malnutrition in Johannesburg (altitude 1800 m). Biochemical evidence of iron deficiency was presented in 26% cases on admission and developed in 90% during recovery. Biochemical evidence of folate deficiency was present in 14% of cases on admission and resolved on dietary therapy alone. Serum erythropoeitin was increased on admission and remained elevated during recovery. There was no relationship between serum erythropoeitin and Hb concentrations. Key enzymes in the red cell glycolytic and hexose monophosphate pathways and red cell membrane showed increased activity. Red cell adenosine triphosphate concentration was increased and unstable. Red cell potassium was decreased and, in the fatal cases, red cell sodium was increased. The possible significance and practical implications of these findings are discussed.

The pyropoikilocytosis-elliptocytosis syndrome in a black South African infant: clinical and hematological features.

A black infant presented in the newborn period with severe red cell fragmentation, pyknocytosis, and hemolysis necessitating repeated exchange transfusions. Exposure of the red cells to 45 degrees C in vitro caused membrane budding, fragmentation, and sphering similar to that described in pyropoikilocytosis. By 12 months of age the clinical and hematologic picture had evolved to one of a compensated hemolytic disorder with elliptocytosis, but the degree of abnormal thermal sensitivity remained unchanged. Osmotic fragility and authohemolysis tests gave results intermediate between hereditary elliptocytosis and hereditary pyropoikilocytosis. It appears that there is considerable heterogeneity within the red cell membrane disorders exhibiting altered thermal sensitivity.

Pure red cell aplasia associated with sodium valproate therapy.

Pure red cell aplasia developed in a 9-year-old girl receiving sodium valproate therapy. Infection with measles and chickenpox had occurred two months previously. Regeneration of bone marrow erythroid precursors was demonstrated one month after drug withdrawal. Readministration of sodium valproate resulted in a second episode of red cell aplasia that again resolved promptly after drug withdrawal. The respective roles of infection and drugs in the etiology of red cell aplasia are discussed.