Newborn screening for abnormal haemoglobins in Jamaica: Practical issues in an island programme.

OBJECTIVE: To report the diagnostic challenges of newborn screening for abnormal haemoglobins. SETTING: Cord blood samples from 13 hospitals in southwest Jamaica taken in 2008-2019. METHODS: Blood spots, collected from the umbilical cord, were analysed by high pressure liquid chromatography (HPLC) to reveal phenotypes for HbSS and HbCC, but genotype confirmation may require parental studies or gene sequencing. Such cases that were successfully traced were analysed in this follow-up study. RESULTS: HPLC screening of 121,306 samples detected HbAS in 11,846 (9.8%), HbAC in 4508 (3.7%) and other electrophoretic abnormalities in 1090 babies. Among 101 previously unconfirmed cases, 34/90 (38%) with HPLC evidence of a HbSS phenotype had other genotypes, and 7/11 (64%) with a HbCC phenotype had other genotypes. Syndromes from the interaction of ß thalassaemia occurred in 112 babies (85 with HbS, 27 with HbC) and of genes for hereditary persistence of fetal haemoglobin (HPFH) in 18 (12 with HbS, 6 with HbC). Variants other than HbS and HbC occurred in 270 babies, 16 in combination with either HbS or HbC, and 254 as traits. Most variants are benign even when inherited with HbS, although HbO Arab, HbD Punjab, or Hb Lepore Washington, which occurred in 6 cases, may cause sickle cell disease. CONCLUSIONS: Genes for ß thalassaemia and HPFH are common in western Jamaica and when associated with HbS may present diagnostic challenges in newborns, as HbF and HbA2 have not reached diagnostic levels. Family and DNA studies may be necessary for genotype confirmation.

Odisha Revisited: A Personal Account.

In 1986, a paper in the Lancet was the first to collate hematology, molecular findings, and clinical features of homozygous sickle cell (SS) disease in India. The paper came from the group organized by Professor Bimal Kar in Burla Medical College, Sambalpur University, in western Odisha. Although widely quoted, few readers will be aware of the history of this work that is now attached in an informal summary.

Causes of death and early life determinants of survival in homozygous sickle cell disease: The Jamaican cohort study from birth.

Globally, the majority of persons born with sickle cell disease do not have access to hydroxyurea or more expensive interventions. The objectives were to estimate the survival in homozygous sickle cell disease, unbiased by symptomatic selection and to ascertain the causes of death in a pre-hydroxyurea population. The utility of early life biomarkers and genetically determined phenotypes to predict survival was assessed. A cohort study based on neonatal diagnosis was undertaken at the Sickle Cell Unit, a specialist clinic delivering care to persons with sickle cell disease in Jamaica. Screening of 100,000 deliveries detected 315 babies with homozygous sickle cell disease of whom 311 have been followed from birth for periods up to 43 years. Pneumococcal prophylaxis and teaching mothers splenic palpation were important, inexpensive interventions. Anticipatory guidance, routine care and out-patient acute care were provided. Each participant was classified as alive, dead, or defaulted (usually emigration). Causes of death were ascertained from clinical records and/or post-mortem reports. Survival was assessed using the Kaplan-Meier function. Sex-adjusted Cox semi-parametric proportional hazards and Weibull modelling were used to assess the effects on survival of biomarkers. Survival to 40 years was 55.5% (95% CI 48.7% to 61.7%). Acute Chest Syndrome (n = 31) and septicemia (n = 14) were significant causes of death at all ages. Acute splenic sequestration (n = 12) was the most common cause of early deaths. Survival was significantly shorter in those with lower hemoglobin at 1 year, high total nucleated count at 1 year, and a history of dactylitis ever. In these hydroxyurea naïve patients, survival into midlife was common. Causes of death were often age specific and some may be preventable. Early life biomarkers predictive of decreased survival in SS disease identify a patient group likely to benefit from close clinical supervision and potentially high risk therapies.

ß-Thalassemia Mutations in Jamaica: Geographic Variation in Small Communities.

Over the last 43 years, surveys of over 200,000 subjects in Jamaica have identified ß-thalassemia (ß-thal) mutations. In most, these genes were detected at birth in patients with sickle cell-ß-thal and so the prevalence and distribution would not be influenced by subsequent clinical course. There were two newborn populations, 100,000 deliveries in the corporate area between 1973-1981 and 84,940 in south and western Jamaica between 2008-2016. A third population, which derived from the Manchester Project in central Jamaica, screened 16,612 secondary school children, aged predominantly 15-19 years, and identified 150 students with the ß-thal trait and 11 with sickle cell [Hb S (HBB: c.20A>T)]- or Hb C (HBB: c.19G>A)-ß-thal. The latter patients may have been subject to symptomatic selection, but this should not have affected those with ß-thal trait. Of the 24 different molecular mutations, ß0-thal genes accounted for 10.0-27.0% of these groups and most common was IVS-II-849 (A>G) (HBB: c.316-2A>G). Of the ß+ mutations, seven subjects had severe genes with low levels of ß chain synthesis but the majority were benign mutations in the promoter region. The -29 (A>G) (HBB: c.-79A>G) mutation dominated in the newborn study in Kingston, similar to experiences in Guadeloupe and African Americans but the -88 (C>T) (HBB: c.-138C>T) mutation was more common among school students in central Jamaica. Caribbean populations are genetically heterogeneous but variations within different parts of Jamaica is of potential importance for prenatal diagnosis and genetic counseling. This information may also be useful among the large Jamaican diaspora.

A Plea for the Newborn Diagnosis of Hb S-Hereditary Persistence of Fetal Hemoglobin.

The gene for hereditary persistence of fetal hemoglobin (HPFH) in the Caribbean is much more common than previously estimated. To avoid labeling persons with the benign syndrome Hb S (HBB: c.20A>T)/HPFH as a disease and wasting scarce resources, parental studies are recommended when newborn screening reveals a pattern consistent with an SS phenotype.

Hb S-ß-thalassemia: molecular, hematological and clinical comparisons.

Clinical and hematological features are presented for 261 patients with identified ß-thalassemia (ß-thal) mutations. Mutations causing Hb S [ß6(A3)Glu→Val]-ß(0)-thal were IVS-II-849 (A>G) in 44%, frameshift codon (FSC) 6 (-A) in 14%, Hb Monroe [ß30(B12)Arg→Thr] in 14%, and IVS-II-1 (G>A) in 10%. Mutations causing Hb S-ß(+)-thal with 14-25% Hb A (type III) were -29 (A>G) mutation in 60%, -88 (C>T) in 22% and the polyadenylation signal site (polyA) (T>C) mutation in 14%, and in Hb S-ß(+)-thal with 1-7% Hb A (type I), all had the IVS-I-5 (G>C) mutation. Hematologically, only minor differences occurred between the four Hb S-ß(0)-thal mutations, but among the three mutations causing Hb S-ß(+)-thal type III, levels of Hb A(2), Hb F, hemoglobin (Hb), MCV and MCH were highest in the -88 and lowest in the polyA mutations. Clinically, Hb S-ß(0)-thal and Hb S-ß(+)-thal type I were generally severe, and Hb S-ß(+)-thal type III disease with the -88 mutation was milder than that caused by the polyA mutation.

Leg ulceration in sickle cell disease: medieval medicine in a modern world.

Leg ulceration is now recognized as an important complication of sickle cell disease, especially of the SS genotype. Since there is no convincing evidence of delayed healing of operation scars or of wounds elsewhere in the body, it must be concluded that factors specific to the lower leg render patients prone to delayed healing at this site. Many lesions are traumatic in origin and since there is considerable variation in healing rates among the normal population, it is useful to define chronic leg ulceration on the basis of a minimal duration, which in Jamaican studies has required at least 3 months and sometimes 6 months before healing. This minimal duration avoids the difficulties of interpreting the significance of briefer lesions since the moment of final healing may be poorly defined (patients may conclude that a scab represents healing whereas small lesions persist beneath) and often goes undocumented as patients may not report and medical attendants may not enquire, the date of final healing.

Red cell antibodies in patients with homozygous sickle cell disease: a comparison of patients in Jamaica and the United Kingdom

The transfusion history and frequency of red cell antibodies in patients with homozygous sickle cell (SS) disease have been compared in 190 subjects from the Jamaican cohort study and 37 patients attending a sickle cell clinic in Manchester, England. The proportion of patients transfused did not differ between the groups although the number of units transfused and the frequency of red cell antibodies were significantly greater in the Manchester group. Immune antibodies occurred in three Jamaicans (2.6 percent of those transfused) and 16 UK subjects (76 percent of those transfused). Multiple antibodies occurred in 10 (63 percent) UK subjects but in no Jamaicans. Indications for transfusion also differed between the groups, Jamaican patients typically receiving 1-2 units for acute anaemia or acute chest syndrome, whereas UK patients frequently had multiple transfusions in preoperative exchange or prophylaxis programmes. The greater red cell alloimmunization among UK patients probably reflects both the greater use of transfusion and the disparity between donor and recipient populations in the UK. (AU)

Significance of fever in Jamaican patients with homozygous sickle cell disease

OBJECTIVE: To investigate the cause and outcome of high fever in Jamaican children with homozygous sickle cell disease. DESIGN: Retrospective review of febrile episodes in a three year period (1 September 1993 to 31 August 1996). SETTING: Sickle Cell Clinic, an outpatient clinic in Kingston run by the Medical Research Council Laboratories (Jamaica). PATIENTS: Patients with homozygous sickle cell disease under 17 years of age presenting with an anxillary temperature o 39.0§c (102.4§F). MAIN OUTCOME MEASURES: Diagnosis, death. RESULTS: There were 165 event in 144 patients (66 (45.8 percent) boys) with a median age of 6.1 years. Bacteraemia was found in 10 (6.1 percent) events (three Streptococcus pneumoniae, two Haemophilus influenzae type b, two Salmonella sp, one Escherichia coli, one Enterobactor sp, and one Acinetobacter sp), and urinary tract infections in four (2.4 percent). All cultures of cerebrospinal fluid were sterile. Acute chest syndrome occured in 36 (21.8 percent) events. A painful crisis was associated with 45 (27.3 percent) events and was the only pathology identified in 20 events (12.1 percent). Hospital admission was necessary in 66 cases including all those with bacteraemia and 31 with acute chest syndrome. There were two deaths: a 5 year old boy with septic shock associated with H influenzae septicaemia, and a 3 year old boy with the acute chest syndrome. CONCLUSIONS: Painful crisis and acute chest syndrome were the most common complications associated with high fever, but other important associated features included bacteraemia and urinary tract infection. Enteric Gram negative organisms accounted for 50 percent of positive blood cultures. (AU)

Jamaican Sbetañthalassaemia: mutations and haematology

The sickling disorders are a common cause of morbidity and mortality in Jamaica. Sickle cell betañthalassaemia is the fourth commonest form, occuring in one in every 3000 births. This is a heterogeneous condition, producing HbS, HbF and HbA2 with variable amounts of HbA, depending on the mutation and, within a defined population, only a few beta-thalassaemia mutations occur at high frequency. This study establishes the frequency of beta-thalassaemia mutations in Sbetañthalassaemia patients in Jamaica. In addition, comparison of the haematological phenotypes is possible by looking at the "average steady-state haematology" of the different mutational groups. Blood samples from 132 unrelated Sbetañthalassaemia patients attending the MRC Sickle Cell Unit at the University of the West Indies were analysed by amplification refractory mutation system (ARMS) polymerase chain reaction (PCR) or sequencing to determine the nature and frequencies of the underlying beta-thalassaemia mutations. Ten mutations were identified, four of which accounted for 93 percent of the patients studied. These were 29 (A --> G) in 71 (54 percent), -88 (C --> T) in 27 (20 percent), polyA (T --> C) in 17 (13 percent) and IVS1-5 (G --> C) in nine (7 percent). The six remaining mutations found at lower frequency were C24 (T --> A) in two patients and one each of IVS2-848 (C --> A), -90 (C --> T), IVS1-5 (G --> T),IVS1-6 (T --> C). In one individual, no mutation was found. The three commonest mutations were all associated with levels of greater than 10 g/dl, whereas IVS1-5 (G --> C) had a more severe haematological phenotype. The predominance of -29 (A --> G) and -88 (C --> T) is in keeping with other studies on populations of African origin. IVS1-5 (G --> C) is found chiefly in Indian populations, and all affected families acknowledged Indian ancestry, reflecting the prominent Indian community in Jamaica. (AU)

Jamaican sickle cell disease: lessons from a cohort study

The Jamaican Cohort Study of sickle cell disease recruited all cases among 100 000 consecutive non-operative deliveries at the Government Maternity Hospital (Victoria Jubilee) between June 1973 and December 1981. There were 315 babies with homozygous sickle cell (SS) disease of whom 311 were followed from birth with active tracing of defaults. During this period, prophylactic penicillin and pneumococcal vaccine were introduced for the prevention of pneumonococcal septicaemia, and parental education in the early detection of acute splenic sequestration was shown to reduce mortality from this complication by 90 percent. To assess changes in survival consequent on these measures, 315 children were divided into three equal groups of 105 children born between 25/6/73 and 27/12/75 (30 months), 28/12/75 and 2/1/79 (36 months), and 3/1/79 and 28/12/81 (36 months). Mortality was assessed by survival curve analysis using the product limit method. Survival was examined from birth to the 15th birthday, and survival curves for each third compared using the log rank test for trend. There were 61 deaths (54 autopsies) before 15 years of age, 28 in the first third, 17 in the second third, and 16 in the last third, the log rank test for trend being of borderline statistical significance (p=0.05). Septicaemia or meningitis accounted for 8, 1 and 5 deaths in the three groups, respectively, and pneumococcal sepsis for 4, 1 and 1 of these deaths. Acute splenic sequestration accounted for 5, 2 and 1 deaths and the interventions (against pneumococcal sepsis and acute splenic sequestration) were assessed by combining these for anlaysis. Together they showed a significant decline in mortality during the study (test for trend, p=0.02). No change was observed in the numbers with acute chest syndrome. Early diagnosis and simple prophylactic measures significantly reduce deaths associated with SS disease.(AU)

The painful crises of sickle cell disease - is Jamaican experience relevant?

Bone marrow necrosis, is the most common cause of the painful crises in the sickle cell disease, is a recurrent cause of morbidity. In Jamaica, these events increase in incidence in late teenage, are most common in young adults and decrease progressively in frequency and severity after the age of 30 years. Precipitating events include cold exposure, exertion, infections, and stress but skin cooling is the commonest factor in Jamaica. Risk factors include pregnancy, especially the last trimester and immediate post partum period and a high haemoglobin level. The MRC Laboratories [Jamaica] undertakes the management of over 5000 patients islandwide and treats 4-12 painful crises daily. Crises admitted to the day care centre are deemed of sufficient severity to require narcotic analgesia and patients are given rehydration and their response to analgesia monitored during the day. After assessment at 4pm. they are given the option of hospital admission or discharge home with similar analgesia in oral form. Over 90 percent elect to return home. It is estimated that the South East London Health Authority spent 1.9 million pounds on the inpatient management of the painful crises last year, four times the entire budget of the MRC Laboratories [Jamaica] which supervises the outpatient clinical care and research programmes among a much larger population. It is proposed that the Jamaican model of outpatient care for the painful crises may provide a more acceptable and less socially disruptive therapeutic approach and would free resources which could be used to improve other aspects of patient care in sickle cell disease. Its applicability should be explored in the United Kingdom.[AU]

Microchromatographic quantitation of hemoglobin A levels in phenotypes of sickle cell-beta thalassemia

The inheritance of the sickle cell gene in combination with a gene for á+ thalassemia results in a spectrum of sickle cell-á+ thalassemia syndromes with varying levels of hemoglobin A (HbA). Some severe sickle cell-á+ thalassemia syndrome have small amounts of HbA, which may be difficult to quantitate in the presence of fetal hemoglobin. A microcolumn chromatographic method, using 0.5 M Tris-acetic acid developers with varying pH values from 9.0 to 6.0 appears to adequately quantitate small amounts of HbA. This method is relatively simple and cheaper than high-performance liquid chromatography, a major consideration in developing countries.(AU)

Improved survival in homozygous sickle cell disease: lessons from a cohort study

OBJECTIVE: To examine whether simple interventions in a sickle cell clinic improve survival in sickle cell disease. DESIGN: Survival curve analysis and hazard ratios in a cohort study followed from birth. SETTING: MRC Laboratories (Jamaica) at the University of the West Indies, and Victoria Jubilee Hospital, Kingston, Jamaica. SUBJECTS: 315 patients with homozygous sickle cell disease detected during the screening of 100,000 consecutive non-operative deliveries between June 1973 and December 1981 at the main government maternity hospital, Kingston, Jamaica. INTERVENTIONS: Prophylactic penicillin to prevent pneumococcal septicaemia, parental education in early diagnosis of acute splenic sequestration, close monitoring in sickle cell clinic. MAIN OUTCOME MEASURES: Survival. RESULTS: Survival appeared to improve, the log rank test for trend comparing the first, second, and last third of the study reaching borderline significance (P = 0.05). Combined deaths from acute splenic sequestration and pneumococcal septicaemia-meningitis declined significantly (test for trend, P = 0.02). CONCLUSION: Early diagnosis and simple prophylactic measures significantly reduce deaths associated with homozygous sickle cell disease (AU)

Glomerulonephritis after human parvovirus infection in homozygous sickle-cell disease

Glomerulonephritis with proteinuria of sufficient degree to manifest the nephrotic syndrome followed aplastic crises induced by human parvovirus (B19) in seven patients with homozygous sickle-cell disease, within 7 days in five patients and 6-7 weeks in two. Segmental proliferative glomerulonephritis was found in all four patients who underwent acute renal biopsies and focal segmental glomerulosclerosis was found in the fifth patient who had a biopsy 4 months later. One patient recovered completely, one died in chronic renal failure after 3 months, and the others had impaired creatinine clearance, four with continuing proteinuria (AU)

Chromatographic quantitation of HbA levels for distinguishing genotypes of sickle-cell á+ thalassaemia - abstract

Sickle-cell á+ thalassaemia represents a spectrum of conditions, depending on the molecular basis of the á+thalassaemia gene. Different genes manifest different levels of beta chain synthesis and hence varying amounts of HbA. Different á+thalassaemia genes also characterise sickle-cell á+thalassaemia in different groups, several of which occur in Jamaica. Commonest among people of African ancestry are the -29 and -88 substitutions which result in a very mild sickle-cell á+thalassaemia type III associated with high HbA levels (18 - 25 percent). The Indian population manifests more severe genes causing sickle-cell, á+thalassaemia type II with 8 - 15 percent HbA and sickle-cell á+thalassaemia type I with 3 - 5 percent HbA. Estimation of the level of HbA is therefore useful in predicting the probable molecular basis for the á+thalassaemia gene and also the expected clinical course. Measurement of HbA by chromatography in sickle-cell á+ thalassaemia requires adequate separation from both HbS and HbF and anew method is presented which appears to give satisfactory results. The method is based on 0.5M Tris-5 percent acetic acid. Duplicate runs on blood samples from 28 patients gave mean (SD) values of 17.4 (6.7) and 17.2 (6.9) with between-run differences of 0.2 (95 percent C.I.,-0.7, 1.1) p = 0.65; 95 percent of the differences between runs were 4.7 percent or less. HbA measurements with this method did not allow the same grouping as in Greece, which may be due to differences in the two populations or to measurement error. The method is relatively simple and of considerably lower cost than high-performance liquid chromatography (HPLC) (AU)

Management of sickle cell disease; lessons from the Jamaican Cohort Study

Sickle cell disease is enormously variable in its expression and outcome. In addition to this intrinsic variablity are the problems of symptomatic selection biasing observations towards the sever end of a wide clinical spectrum and a truly changing natural history as a result of better management. Against this background, there was a need for a description of the disease in a truly representative sample of patients and this objective has been approached in the Jamaican Cohort Study of Sickle Cell Disease. Initiated in 1973, this study is based on all cases of sickle cell disease detected among 100,000 consecutive normal deliveries in Kingston, Jamaica. All affected children as well as age matched normal controls have been followed prospectively and are currently ages 11 to 19 years. The following review is based on lessons learnt from this cohort study. It is not intended to be a comprehensive survey of knowledge of sickle cell disease and does not address major contributions from studies elsewhere. In some ways, therefore, the review may appear unbalanced because of this specific objective. However, a great deal has been learnt about the evolution of the abnormal haematology of sickle cell disease and its relationship to clinical features. The causes of early mortality in sickle cell disease in Jamaica are described and the major complications such as acute splenic sequestration, pneumococcal septicaemia, aplastic crisis, hypersplenism, and acute chest syndrome have been addressed with varying success. Overall survival to the age of 19 years has been 75 percent and it is planned that the study should continue to define the problems of late adolescence and early adult life (AU)