An evaluation of the detection and support facilities available for women of child-bearing age with haemoglobinopathies at the antenatal clinic of a hospital in Kingston, Jamaica and their impact on these clients

An evaluation of the detection and support facilities available for women of child-bearing age with haemoglobinopathies at the antenatal clinic of a hospital in Kingston, Jamaica and their impact on these clients. The haematology laboratory can be regarded as playing a pivotal role in the delivery of quality health care. Accuracy and early detection of many genetically transmitted diseases hinge on the reliability of screening tests, their interpretation and the liaison between nurse/clinican, the laboratory and their clientele. This project evaluated the laboratory services offered for screening haemoglobinopathies among persons attending the antenatal clinic of the University Hospital of the West Indies, Kingston, Jamaica. A case control study was conducted during the months December 1996 through July 1997 by means of accessing laboratory records, patients' dockets and the administering of questionnaires to mothers with the haemoglobinopathies (cases)and those without, (controls). Findings analysed from the dockets and questionnaires reveal that the antenatal clinic accounts for approximately one third of the the request made to the laboratory by the hospital for haemoglobin electrophoresis. The relative frequenceis of haemoglobinopathies was consistent with that of other studies AS 10 percent; AC 3 percent; SS < or = to 1percent; SC < or = to 1 percent. The screening test used was fairly reliable for preliminary screening but needs to be followed by diagnostic tests which are not being done at this time, for confirmation of genotypes. Both groups were similar in age distribution but differed in respect of knowledge of sickle cell status of self, family members and sickle cell disease. Among the case group greater than 60 percent of the times they did not know their husbands'/partners sickle status or that of his family members. Only 82 percent of respondents knew their correct sickle status (74 percent of cases; and 90 percent of the controls). The study groups differed with regard to educational level, race of fathers and union status. More subjects with a haemoglobinopathy than those in the control group... (AU)

An evaluation of the detection and support facilities available for women of child-bearing age with haemoglobinopathies at the antenatal clinic of a hospital in Kingston, Jamaica and their impact on these clients

The haematology laboratory can be regarded as playing a pivotal role in the delivery of quality health care. Accuracy and early detection of many genetically transmitted diseases hinge on the reliability of screening tests, their interpretation and the liaison betweem nurse/clinician, the laboratory and their clientele. This project evaluated the laboratory services offered for screening haemoglobinopathies among persons attending the antenatal clinic of the University Hospital of the West Indies, Kingston, Jamaica. A case control study was conducted during the months December 1996 through July 1997 by means of accessing laboratory records, patients' dockets and the administering of questionnaires to mothers with the haemoglobinopathies (cases) and those without, (controls). Findings analysed from the dockets and questionnaires reveal that the antenatal clinic accounts for approximately one third of the requests made to the laboratory by the hospital for haemoglobin electrophoresis. The relative frequencies of haemoglobinopathies with that of other studies AS 10 percent; AC 3 percent; SS < or = 1 percent; SC < or = 1 percent. The screening test used was fairly reliable for preliminary screening but needs to be followed by diagnostic tests which are not being done at this time, for confirmation of genotypes. Both groups were similar in age distribution but differed in respect of knowledge of sickle cell status of self, family members and sickle cell disease. Among the case group greater than 60 percent of the times they did not know their husbands'/partners's sickle status or that of his family members. Only 82 percent of respondents knew their correct sickle status (74 percent of cases; and 90 percent of the controls). The study groups differed with regard to educational level, race of fathers and union status. More subjects with a haemoglobinopathy than those in the control group attained college and university level and this may be responsible for the impact on level of awareness. Race of both groups were similar except that fathers in the case group were significantly less likely to be black when compared to the control group. Women in the control group were more likely to be married or in common-law union than those in the case group. Plans for having children were similar in both groups and showed the "high-risk" women either had no regard for, or are ignorant of the implication for transmitting the sickle cell gene.(Au)

The haematology of homozygous sickle-cell disease - abstract

The purpose of the study was to investigate age- and sex-related variations in the haematology of older patients with SS disease, in order to determine haematological characteristics possibly favouring survival. Steady state haematology was available in 181 patients aged 40-73 years. There appeared to be no consistent sex differences in any of the indices examined. Longitudinal analyses were performed for the 133 patients with at least two observations, using analysis of covariance (ANCOVA) methods. Highly significant declines in total haemoglobin (Hb), platelet counts and absolute reticulocyte count were displayed in both sexes. Overall, Hb levels decreased by approximately 0.076 gm/dl/year in females and 0.113 gm/dl/year in males. Significant increases occurred in HbA, HbF and MCV in females only. The total nucleated count (NBC) fell with age, although the decline was only significant in females. These observations are consistent with a progressive bone marrow failure which is not explained by the commonly occurring renal impairment in older SS patients since the changes persisted in analyses confined to the 84 patients with normal creatinine levels (C=120 æmol/l). The mechanism for this bone marrow failure is currently unknown. The prevalence of homozygous alpha thalassaemia in the study group (4.4 percent) was similar to that in the overall SS population, providing no evidence that this may lead to improved survival, as has been suggested (AU)

The red cell distribution width in sickle cell disease: is it of clinical value?

The red cell distribution width (RDW) has been studied during the clinical steady state in 1121 patients with homozygous sickle cell (SS) disease, 344 with sickle cell-haemoglobin C (SC) disease, 68 with sickle cell-beta+ thalassaemia, 49 with cell beta§ thalassaemia and in 130 control subjects with a normal (AA) genotype. The mean RDW was moderately increased in Sbeta+ thalassaemia and SC disease and markedly increased in Sbeta§ thalassaemia and SS disease. In SS, SC and Sbeta§ thalassaemia genotypes, lower RDW values occurred in females and with alpha thalassaemia. The RDW correlated negatively with total haemoglobin, mean cell haemoglobin concentration, mean cell volume and fetal haemoglobin (HbF) and positively with reticulocyte count in SS disease. A low RDW was associated with higher weight and less frequent dactylitis, painful crisis, acute chest syndrome, acute splenic sequestration and hospital admissions. A low RDW in SS disease is consistent with a high total haemoglobin, high HbF, low reticulocyte count, alpha thalassaemia and a more mild clinical course. (AU)

Alpha thalassemia and the hematology of homozygous sickle cell disease in childhood

Alpha thalassemia modifies the gematolic expression of homozygous sickle cell (SS) disease, resulting in increased total hemoglobin and HbA2 and decreased HbF, mean cell volume, reticulocytes, irreversibly sickled cells, and biliru-bin levels. The age at which these changes develop in children with SS disease is unknown. Ascertainment of globin gene status in a large representative sample of study the gematologic indices in nine children homozygous for Alpha thalassemia 2 (two-gene group), 90 children heterozygous for Alpha thalassemia 2 (three-gene group), and 167 children with a normal Alpha globin gene complement (four-gene group). The two-gene group had significantly lower mean cell volumes from birth, higher red cell counts from one month, lower reticulocytes from three months, and higher HbA2 levels from one year, as compared with the four-gene group. Children with three genes had intermediate indices but resembled more closely the four-gene group. Differences in total hemoglobin or in fetal hemoglobin between the groups were not apparent by eight years of age. The most characteristic differences of the two-gene group were the raised proportional HbA2 level and low mean cell volume, the latter having some predictive value for Alpha thalassemia status at birth.(AU)

Haematological change in sickle cell-haemoglobin C disease and in sickle cell-beta thalassaemia: a cohort study from birth

The haematological changes in early years following neonatal diagnosis have been observed in representative groups of children with sickle cell-haemoglobin C (SC) disease, sickle cell-á+ thalassaemia, and in sickle cell-á Thalassaemia. Most haematological indices in SC disease were intermediate between previously published values in SS disease and in AA controls, generally being closer to values in normal children, Eceptions were microcytosis which may be genetically determined and a striking elevation of mean cell haemoglobin cocentration from age 2 months to 4 years. The combination of a raised MCHC and a lowered MCV is unusual and may be characteristic of SC disease. Features in sickle cell-á thalassaemaia generally differed accordingly to the type of á thalassaemia gene. Sickle cell-B degree thalassaemia had lower levels of haemoglobin, MCHC, red cell count, MCV, and higher reticulocytes, most differences being significant before 1 year. No differences between SB degree thalassaemia and Sá+ thalassaemia were apparent in HbF levels (which resembled those in SS disease) or in HbA2 levels (which exceeded those in SS disease by 1 year of age).(AU)

The haematology of steady state homozygous sickle cell disease: frequency distibutions, variation with age and sex, longitudinal observations

The steady state haematological characteristics observed in 1071 patients with homozygous sickle cell (SS) disease aged 5-66 years are presented (Summary)

A trial of folate supplementation in children with homozygous sickle cell disease

A double blind controlled trial of supplementation with folic acid has been performed in 117 children with homozygous sickle cell (SS) disease aged 6 months to 4 years over a 1 year period. No megaloblastic change was observed in either group. At the end of the study period the folate supplemented group showed no significant differences in haemoglobin, growth characteristics, or in the proportion of children affected by major or minor infections, acute splenic sequestration, dactylitis or episodes of bone or abdominal pain. However, the folate supplemented groups showed a significantly lower mean cell volume and the placebo group contained a significant excess of children experiencing multiple episodes of datylitis. The results are compatible with mild folate deficiency in some patients in the placebo group but the absence of striking effects on haematology or growth suggest that the policy of regular folate supplementation in children with SS disease should be critically reviewed (AU)

Post-natal decline of fetal haemoglobin in homozygous sickle cell disease: relationship to parental Hb F levels

The decline of fetal haemoglobin (Hb F) from birth to 6 years has been compared in a cohort of 266 Jamaican children with homozygous sickle cell (SS) disease and in 243 matched controls with a normal haemoglobin (AA) genotype. Hb F levels were significantly higher in the SS cases from 1 month onwards but, unlike the normal controls, no sex differences was apparent. The Hb F levels in SS disease were significantly correlated with parental Hb F levels, suggesting that genetic factors regulating adult Hb F levels are active at earlier stages in development. Furthermore, some of these genetic determinants of Hb F production may be linked to the á-like globin gene complex and be in linkage disequilibrium with the áý allele (Summary)

The interaction of alpha-thalassemia and homozygous sickle-cell disease

Patients with homozygous sickle-cell disease may be homozygous for alpha-thalassemia 2 (O-/O-), may be heterozygous for alpha-thalessemia 2 (O-/OO), or may have a normal alpha-globin-gene complement (OO/OO). We compared the clinical and hematologic features of 44 patients who had sickle-cell disease and homozygous alpha-thalassemia 2 with those of controls with the two hematologic conditions. The patients with homozygous alpha-thalassemia 2 had significantly higher red-cell counts and levels of hemoglobin and hemoglobin Aý, as well as significantly lower hemoglobin F, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, mean corpuscular volume, reticulocyte counts, irreversibly-sickled-cell counts, and serum total billirubin levels, than those with a normal alpha-globin-gene complement. Heterozygotes (O-/OO) had intermediate values. In the group with homozygous alpha-thalassemia 2, fewer patients had episodes of acute chest syndrome and chronic leg ulceration and more patients had splenomegaly, as compared with patients in the other two subgroups. These data confirmed previous suggestions that alpha-thalassemia inhibits in vivo sickling in homozygous sickle-cell disease and may be an important genetic determinant of its hematologic severity.

The development of haematological changes in homozygous sickle cell disease: a cohort study from birth to 6 years

A cohort study of sickle cell disease from birth has allowed observations on the disease without the symptomatic selection inherent in previous series. The development of haematological indices from birth to 6 years in male and female infants with homozygous sickle cell (SS) disease is presented and compared with values in age and sex matched controls with a normal haemoglobin (AA) genotype previously presented elsewhere. In SS disease total haemoglobin levels fell rapidly from birth to a plateau at 3-6 months before falling again to 15 months after which no age related change occured. Mean cell haemoglobin concentration fell from birth to lowest values at 15-18 months before increasing to reach the level present at birth by the age of 5 years. Red cell counts fell rapidly after birth to a plateau at 2 months, increased slightly to 2 months and then fell steadily throughout the remaining period of study. The mean cell voloume and mean cell haemoglobin also fell rapidly after birth reaching the lowest values by 6 months and then increased progressively. Female patients showed significantly higher haemoglobin levels from 15 months to 4« years. Compared to AA controls, SS patients manifested significantly lower levels of haemoglobin from 2 weeks, and red cell counts from 1 month, and significantly higher levels of MCHA from 4 months to 3 years, MCV from 8 months to 5 years, and serum iron levels from 1 to 4 years. Children with SS disease were partially protected from iron deficiency in early childhood, perhaps by increased intestinal absorption of iron, and the associated increase in intracellular haemoglobin concentration might be disadvantageous during this high risk period (Summary)

Haematological indices in normal negro children: a Jamaican cohort from birth to five years

Haematological indices, including total haemoglobin, mean cell haemoglobin concentration, red cell count, mean cell volume, mean cell haemoglobin, reticulocytes, and serum iron values, in a cohort of 243 randomly selected Negro children with normal haemoglobin genotype, followed from birth to 5 years, are reported. Total haemoglobin fell rapidly from high levels at birth to a plateau at 2-6 months, a secondary fall occurred after 6 months and a gradual increase after 18 months. The red cell count also fell rapidly, but increased after 2 months to a plateau and then slowly declined from age 1-5. Mean cell volume and mean cell haemoglobin fell continously from birth to the lowest values at 15 months and then progressively increased to the age of 5 years. Serum iron levels were low at one year of age (mean 9.7 mumol/1) increasing slowly by age 4 and sharply by age 5. Mean cell haemoglobin concentration fell gradually to 1-1 1/2 years and then increased progressively to age 5. Values for Hb, MCHC, MCV, and MCH were consistently and often significantly lower in males before the age of 2 years, compatible with greater depletion of iron stores. Serum iron values were generally lower in males but there was no sex difference at one year when highly significant differences in Hb, MCHC, MCV, and MCH occurred. The cause of sex differences in early haematological development is currently unclear (AU)