Haematological Changes Associated with Hepatitis B Virus Infection in Individuals with and without Sickle Cell Disease.

BACKGROUND: Hepatitis B virus infection, a major public health problem that primarily affects the liver, may cause reduction in the levels of haemoglobin, haematocrit and in the extreme, could cause aplastic anaemia. The haematological characteristics could be detected with a complete blood count which could provide invaluable information for diagnosis and management of the disease. AIM: To determine the effect of HBV infection on the blood count of individuals with sickle cell disease (SCD) and apparently normal healthy (Non-SCD). SETTING: Non-SCD participants were recruited from the community while SCD patients in steady state were recruited from SCD routine clinics. METHODS: The study was a cross - sectional study carried out on 1017 non-SCD and 1017 SCD individuals. Haematology Autoanalyzer was used to determine the complete blood count. Granulocyte-to-lymphocyte ratio (GLR), platelet to white blood cell count ratio (PWR) and platelet-to-lymphocyte ratio (PLR) were calculated. ELISA for HBsAg and HBV core antigen IgM antibodies were used to identify participants with HBV. RESULTS: The non- SCD individuals infected with HBV had significantly higher WBC (7.51 ± 5.8 X109/L)) compared to a WBC (6.1 ± 3.4 X109/L) in uninfected individuals (p =0.001). PWR for HBV negative (49.9±28.6) was higher than that for HBV positive participants (41.4±17.6) (p=0.034). Mean platelet volume (MPV) of 9.93 ± 1.1fl in SCD individuals with HBV was significantly higher than 8.30 ± 0.95fl in SCD individuals without HBV (p=.001). CONCLUSIONS: PWR and MPV may be useful as surrogate marker for detection of HBV disease progression in apparently normal healthy non - SCD and SCD populations to institute prompt appropriate ancillary investigation and treatment.

CONTEXTE: L'infection par le virus de l'hépatite B, un problème majeur de santé publique qui affecte principalement le foie, peut entraîner une réduction des taux d'hémoglobine et d'hématocrite et, dans l'extrême, peut provoquer une anémie aplastique. Les caractéristiques hématologiques peuvent être détectées par un hémogramme complet qui pourrait fournirdes informations précieuses pour le diagnostic et la et la gestion de la maladie. OBJECTIF: Déterminer l'effet de l'infection par le VHB sur sanguine complète d'individus atteints de drépanocytose (SCD) et d'individus apparemment normaux en bonne santé (non-SCD). SITE: Les participants de non-SCD ont été recrutés dans la communauté tandis que les patients drépanocytaires en état stable ont été recrutés dans les cliniques de routine de la drépanocytose. MÉTHODES: L'étude était une étude transversale menée sur 1017 personnes non-SCD et 1017 personnes SCD. sur 1017 personnes nonSCD et 1017 personnes SCD. Un autoanalyseur hématologie a été utilisé pour déterminer la formule sanguine complète. Le rapport granulocytes/ lymphocytes (GLR), le rapport plaquettes/blancs (PWR) et le rapport plaquettes/lymphocyte (PLR). ont été calculés. Les tests ELISA pour les anticorps IgM de l'Ag HBs et de l'antigène central du VHB ont été utilisés pour identifier les participants atteints du VHB. RÉSULTATS: Les individus non atteints de DSC et infectés par le VHB présentaient les caractéristiques suivantes un nombre significativement plus élevé de GB (7,51 ± 5,8 X109/L) par rapport à une WBC (6,1 ± 3,4 X109/L) chez les individus non infectés (p =0,001). Le TPM pour lesparticipants négatifs pour le VHB (49,9±28,6) était plus élevé que celuipour les participants positifs au VHB (41,4±17,6) (p=0,034). Le volume moyen des plaquettes Le volume plaquettaire moyen (VPM) de 9,93 ± 1,1fl chez les personnes atteintes de MCS avec VHB était significativement plus élevé que celui des personnes atteintes de MCS sans VHB (8,30 ± 0,95fl) (p=0,001). sans VHB (p=0,001). CONCLUSIONS: Le PWR et le MPV peuvent être utiles comme marqueurs de substitution pour la détection de la progression de la maladie VHB chez population de SCD et Non-SCD apparemment normale, en bonne santé afin d'instituer rapidement les examens complémentaires et le traitement appropriés.

Atopy is associated with asthma in adults living in rural and urban southwestern Nigeria.

RATIONALE: Factors affecting the course of asthma are not clearly understood in rural and urban communities within low-resource countries. Furthermore, the interactions between atopy, environmental exposure, and helminthic infections in modulating asthma have not been well investigated. OBJECTIVES: To conduct a feasibility study to examine the relationship between atopy and asthma in adults at two rural Health Centers and urban university college hospital in southwestern Nigeria. METHODS: A convenient sample of 55 consecutive patients with stable physician-diagnosed asthma and 55 age-matched nonasthmatic controls seen at the outpatient clinics in two rural Health Centers and an urban university hospital were enrolled. All subjects underwent blood test, allergy skin test, and stool examination for ova and parasites. Wilcoxon sign-rank tests were used to compare serum eosinophilia and allergy skin test between the two groups. RESULTS: Asthmatics in both urban and rural settings had significantly more positive skin reactions to house dust mite, cockroach, mold, and mouse epithelium than nonasthmatic controls (p < .05). Mean total serum IgE was also significantly higher in asthmatics than in nonasthmatic controls (360 vs. 90 IU/L, p <.001). Stool parasitemia was infrequent in both groups and not statistically significant. CONCLUSION: Atopy is associated with adult asthma in southwest Nigeria. Larger studies to confirm the nature of this association and to examine the role of helminthic infection and other environmental factors on the expression of asthma are needed.

Cytochrome P450 CYP2C19 genotypes in Nigerian sickle-cell disease patients and normal controls.

BACKGROUND AND OBJECTIVE: Subjects with different CYP2C19 genotypes may metabolize proguanil, a pro-drug used for malaria prophylaxis differently and the frequency of the different alleles may be different in patients with sickle-cell disease (SCD) and normal controls. The objective of this study was to evaluate CYP2C19 *1, *2 and *3 allele and genotype frequencies in Nigerian normal controls and SCD patients, and to further compare variant CYP2C19 frequencies in Nigerians with other African populations. METHODS: Genotyping was carried out with PCR and restriction fragment length polymorphism analysis. RESULTS AND DISCUSSION: CYP2C19 *1 (84·3 vs. 84·9%) or *2 allele frequency (15·7 vs. 15·1%) was not significantly different between patients with SCD and normal subjects. No *3 allele was detected in the cohort. The SCD group exhibited a statistically significantly lower frequency of *1/*1 genotype (69·6%) compared with normal controls (74·4%). Frequency of *2/*2 was significantly lower in SCD (0·9%) compared with normal controls (4·7%). Frequencies of *1/*2 (29·6 vs. 20·9%) were no different in SCD and normal controls. CONCLUSION: Prevalence of CYP2C19 polymorphisms was defined for the first time in Nigerian normal and SCD populations. Nigerian SCD patients exhibited significantly lower CYP2C19 *1/*1 and *2/*2 frequencies than normal controls. No differences were detected in CYP2C19 allele or genotype frequencies in normal subjects between this study and previous reports in other African populations.

High rate of mixed and subpatent malarial infections in southwest Nigeria.

The rate of malarial parasitemia in children and adults was assessed by microscopy and the polymerase chain reaction in a holoendemic area in Nigeria. A high rate of subpatent Plasmodium falciparum parasitemia (19.6%) was found. Plasmodium malariae and P. ovale infections were common in a rural area (26.1% and 14.8%) but were observed sporadically in individuals from an urban area. Simultaneous infections with P. falciparum, P. malariae, and P. ovale were frequent in the rural area (11.7% triple infections). The rate of triple infections was higher than expected from the prevalences of each species (P < 0.00001). Spleen enlargement was associated with mixed infections of P. falciparum and P. malariae (odds ratio [OR] = 5.9, 95% confidence interval [CI] 3.0-11.7) and less frequently observed in individuals without detectable parasitemia (OR = 0.06, 95% CI = 0.01-0.3). Spleen enlargement and titers of antibodies to schizonts were positively correlated with parasite densities. The results also suggest that in some individuals a long-lasting subpatent parasitemia might occur.

Impact of subpatent multi-species and multi-clonal plasmodial infections on anaemia in children from Nigeria.

Childhood anaemia in sub-Saharan Africa is often caused by Plasmodium falciparum malaria. The influence of subpatent, multi-species and polyclonal infections with malaria parasites on haematological parameters was assessed in 1996/97 in clinically healthy children in Nigeria. Of the 228 children studied, 64% were anaemic by the WHO age-dependent criteria. A univariate analysis of risk factors indicated that the prevalence of anaemia was dependent on the number of Plasmodium species detected by species-specific PCR (P < 0.0001). Furthermore, the prevalence of anaemia increased gradually with the complexity (P < 0.003) as well as with the extent of P. falciparum parasitaemia (P < 0.0001). A logistic regression analysis revealed that individuals with an enlarged spleen tended to be anaemic. The number of Plasmodium species by which an individual was infected was independently associated with anaemia (P < 0.03). ANOVA revealed that the age-corrected values for haemoglobin (Hb) and red blood cells (RBCs) were mainly influenced by the occurrence of mixed infections. Haematological parameters were also influenced by the number of different P. falciparum clones by which an individual was infected. Hb levels and RBC counts were further diminished by additional infections with P. malariae and/or P. ovale. However, the effect of multi-species infections on haematological parameters exceeded that of multi-clonal infections.

Norplant use by women with sickle cell disease.

OBJECTIVE: To assess the safety of Norplant contraceptive implant use by women with mild-moderate homozygous sickle cell disease (HbSS). METHOD: Prospective observation of women pre- and post-insertion of Norplant, with each woman serving as her own control. PARTICIPANTS: 25 women 18-40 years of age who attended a hospital sickle cell clinic; post-insertion data were available for 23 women. OUTCOME MEASURES: Changes in hematologic parameters including PCV, MCV, reticulocytes, ISCs, HbF and bilirubin; changes in biochemical parameters including HDL cholesterol, aspartate transaminase, alkaline phosphate, serum creatinine and serum albumin. RESULT: With a mean follow-up of 12.4 months (range 1-29 months), there were no clinically or statistically significant group or individual changes in the hematologic or biochemical parameters after Norplant insertion. CONCLUSION: Norplant appears to be a safe and appropriate contraceptive for women with mild-moderate HbSS disease.

Persistent hepatomegaly: an index of severity in sickle cell anaemia.

Eighty sickle cell anaemia patients, 29 with persistent hepatomegaly and 51 without, were evaluated with respect to clinical severity score. Haemoglobin F (HbF) was also determined in 52 patients, 20 with persistent hepatomegaly and 32 without. The severity scores were computed from the steady state haematocrit, number of transfusions per year, and number of crises per year. The HbF level was determined by the alkali denaturation method. The patients with persistent hepatomegaly had significantly higher clinical severity scores (P < 0.001) and significantly lower levels of HbF (P < 0.0001). The implication of the finding is that patients with persistent hepatomegaly may have a more severe clinical course than those without, and clinicians managing them may have to pay more particular attention to them. In effect, persistent hepatomegaly may be a useful indicator of severity in sickle cell anaemia.

Molecular epidemiology and activity of erythrocyte G6PD variants in a homogeneous Nigerian population.

OBJECTIVE: To determine accurately the relative frequencies and enzyme activities of the polymorphic variants of G6PD in a homogeneous population in Nigeria. SETTING: Abanla village in the outskirt of Ibadan city and the University College Hospital, Ibadan Nigeria. SUBJECT: Seven hundred and twenty one subjects who belong to the Yoruba tribe of Southwestern Nigeria. METHOD: Two mls of blood was withdrawn from each subject. G6PD activity was quantified by spectrophotometry. DNA was extracted for genotyping of G6PD by PCR. RESULTS: G6PD deficiency was 23.9% and 4.6% in males and females respectively. The gene frequencies of the different G6PD variants (Gd) were in accordance with expected Hardy-Weinberg equilibrium. Only GdA-1 type was found in subjects with deficient variants. G6PD activity decreased significantly with age among non-deficient individuals. The range of enzyme activities was wide and overlapping among the different G6PD variants. CONCLUSION: G6PD deficiency was very high in the population. The gene frequencies were similar to previous findings. Molecular methods of typing G6PD allowed for direct and accurate genotyping of the enzyme in both males and females without having to combine several methods.

Influence of crisis on haemoglobin F level in adult Nigerian sickle cell anaemia patients.

Forty-six Nigerian adult sickle cell anaemia patients were investigated, each in sickle cell crisis and steady state. Forty-three patients had vaso-occlusive crisis while three had haemolytic episodes. Investigations included Packed Cell Volume (PVC), Reticulocyte count and Haemoglobin F estimation. PCV was carried out by the microhaematocrit method while the reticulocytes were counted manually. Haemoglobin F was estimated by the Alkali Denaturation Technique. There was significant anaemia (p < 0.05) and reticulocytosis (p < 0.0001) during the period of crisis compared to the steady state. There was no significant difference (p > 0.05) between HbF level in crisis and that in the steady state. In other words the previously documented increase in HbF during reticulocyte response did not take place in our model. Maybe a 'critical' level of reticulocytosis was not attained. It was also shown that vaso-occlusive crisis did not induce an increase in HbF level suggesting that HbF might be genetically determined at a constant low level throughout life in each of our patients.

Prevalence of asymptomatic parasitaemia in an urban and rural community in south western Nigeria.

The prevalence of malaria parasitaemia was investigated among secondary school students in Ibadan city and a neighbouring rural community in Nigeria. Of 343 urban and 249 rural seemingly healthy subjects examined, 8 pc and 27 pc respectively were found positive for malaria parasitaemia. This showed a significantly higher parasite rate in the rural area as compared to the urban areas (p < 0.05). Only P. falciparum was found in the urban subjects while 7.4 pc of the rural infection was due to P. malariae. All the different erythrocytic stages both sexual and asexual forms of P. falciparum were seen in the rural samples whereas no schizont was seen in the urban samples. The haemoglobin genotype did not affect the prevalence of parasitaemia in the two populations studied. However, a lower parasite rate was observed among G6PD deficient subjects in both populations. There was also a significantly lower parasite infection rate among those with the B-antigen in the two populations studied.

Haemoglobin A2 (Hb A2) and malaria.

The Packed Cell Volume (PCV), reticulocyte count and Hb A2 were determined in 28 patients during the period of malaria parasitaemia and 14 days after effective treatment. The Hb A2 was determined by cellulose acetate haemoglobin electrophoresis in alkaline medium followed by elution in water. There was no statistically significant difference between the PCV during the period of parasitaemia and that after treatment (p > 0.05). The Hb A2 level did not show any significant difference during and after treatment of malaria (p = 0.05). The correlation coefficient between absolute parasite count and Hb A2 level was -0.22 (p = 0.251). It is concluded that malaria parasitaemia does not induce a significant change in the level of Hb A2.

Sickle cell anaemia in a 60 year old Nigerian.

The case of a sixty-year-old Nigerian with sickle cell anaemia is presented. His steady state haematocrit is 0.26 L/L. Haemoglobin F. and HbA2 measured 7.00% and 2.9% respectively. Bone pain crisis occurred very infrequently (one or less per year) but jaundice is always present. A right nephrectomy for haematuria was carried out in Dublin, Ireland, in 1954 when he had his first ever blood transfusion. He was hospitalised for the first time in Nigeria on 21/7/83 in anaemic cardiac failure with haematocrit of 0.14 L/L during which he had the second blood transfusion. Chronic leg ulcer, avascular necrosis of the femoral head and cholelithiasis were absent. He had led a fairly active life and recently retired (1986) as a bursar from a secondary school.

Foetal haemoglobin levels in sickle cell anaemia in Nigerians.

Many patients with sickle cell anaemia (SCA) are known to synthesize increased amounts of foetal haemoglobin (Hb F). In some situations, the levels attained are so high that the course of the disease is ameliorated since Hb F does not participate in the polymerization process characteristic of the sickling phenomenon. It has also been reported that the simultaneous inheritance of an alpha-thalassaemia gene reduces the severity of SCA. We have examined the levels of Hb F in relation to the erythrocyte indices and the coinheritance of the deletion type alpha-thalassaemia in SCA patients in Nigeria. The concentration of Hb F in peripheral blood was measured by the alkali denaturation technique of Betke et al. [15], whilst erythrocyte indices were determined on a Coulter S plus II counter. Alpha-thalassaemia was detected by the restriction endonuclease analysis of DNA obtained from peripheral white blood cells (WBC) and nucleated red cells using alpha-globin gene-specific probes. The mean Hb F level in 130 SCA subjects was 5.9 +/- 3.8% (range 0.9-16%). Males had significantly lower levels than females. Hb concentration, haematocrit, and Hb A2 did not differ in subjects with Hb F levels lower than 2% (Group I) when compared with those whose Hb F levels were higher than 8% (Group II). The mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH) were lower in Group I. Globin analysis in 30 of these subjects showed that 20 had four, eight had three, and two had two alpha-globin genes.(ABSTRACT TRUNCATED AT 250 WORDS)

Haemoglobin DIbadan in a haemoglobin S endemic population.

Haemoglobin DIbadan (beta 87 threonine leads to lysine) was originally found in Ibadan, an area with a high incidence of sickle cell haemoglobin (HbS). Since haemoglobin D and S are indistinguishable by most common conventional methods, the geographical coincidence of the two haemoglobin poses a serious screening problem which was investigated in the propositus who is heterozygous for S and D, his wife who is heterozygous for A and S, and their six children. The combined techniques of haemoglobin solubility, sickling rate, shaking test and routine electrophoresis have yielded an unequivocal diagnosis of the haemoglobin types of the family both for identification and quantitative estimation of the percentage of haemoglobins in the heterozygotes. HbD was found to be slightly less soluble than HbA but otherwise normal blood from S+D individuals was found to contain 57-60% HbD suggesting an increased systhesis of HbD relative to S, whereas A+D heterozygote has 41% HbD suggesting a diminished synthesis of HbD relative to HbA. The physicochemical characteristic of HbD and the haematological data in simple heterozygotes are normal.

Distribution of ABO and RH genes in Nigeria.

Phenotype and gene frequencies of ABO and RH (D) systems were studied in 37,846 random blood donors in five zone of Nigeria (South West) (Yoruba)--Zone A, North West (Hausa-Fulani)--Zone B, Plateau (Birom)--Zone C, South East (Igbo)--Zone D and North East (Kanuri)--Zone E). We assessed the micro differences of genetic markers of ABO and RH blood groups between the ethnic groups in the ABO and RH blood group systems. Gene frequencies were ABO *O = 0.7068, ABO *A = 0.1490, ABO *B = 0.1443, RH *D = 0.8150 and results are similar to those earlier reported. Phenotype frequencies of the blood groups were in agreement with Hardy-Weinberg equilibrium expectations, except in two zones B and C where deviation was thought to be due to a high frequency of blood group AB.

HpaI polymorphism and the sickle gene in Nigerians.

The HpaI restriction fragment length polymorphism linked to the beta globin gene was studied in 181 Nigerian subjects. The beta s gene was found in the 13 kilobase (kb) HpaI fragment in 98.4 percent and in the remaining 1.6 percent of the cases in the HpaI 7.6 kb fragment. The majority of beta A genes (94.2%) were found in either the 7.6 or the 7.0 kb fragment whilst the remainders (5.8%) were in the 13.0 kb fragment. The rare, but not zero, associations of beta A with the 13 kb linkage and of beta s genes with the 7.6 kb fragment would lessen the accuracy in the prenatal diagnosis of sickle cell anaemia in this population through the use of the HpaI polymorphism.

Effects of alpha thalassaemia and haemoglobin F (HbF) level on the clinical severity of sickle-cell anaemia.

Three clinical parameters - average steady-state haematocrit (ASSH), number of crises per year (Cr/Y), and number of transfusions per year (Tx/Y) - were evaluated in 52 patients with sickle-cell anaemia in relation to their foetal haemoglobin (HbF) levels. No correlation was observed between HbF and any of these parameters. A comparison of these three clinical parameters and the alpha globin gene status was also made in 28 of these patients. The relationships between (ASSH) or (Cr/Y) and alpha globin gene status were not significantly different (p > 0.05) but a significantly different value (p < 0.05) was observed between (Tx/Y) and the alpha globin gene status in these patients. It is concluded that, although HbF levels did not affect any of these parameters, alpha thalassaemia deletion significantly reduces the transfusion requirements of these patients.

Hpa-I polymorphism and the sickle gene in Nigerians.

The Hpa-I restriction fragment length polymorphism linked to the beta globin genes was studied in 181 Nigerian subjects. The beta S gene was found to be linked to the 13 kilobase (kb) Hpa-I fragment in 98.4 percent while 1.6 percent was linked to the Hpa-I 7.6 kb fragment. The majority of beta A genes (94.2%) was found to be linked to either the 7.6 or 7.0 kb fragment whilst the remainder (5.8%) was linked to the 13.0 kb. The beta A 13 kb linkage and the small proportion of the beta S genes linked to the 7.6 kb fragment would lessen the accuracy of the Hpa-I polymorphism in the prenatal diagnosis of sickle cell anaemia in this population.

Relationship of foetal haemoglobin levels and beta s haplotypes in homozygous sickle cell disease.

The foetal haemoglobin (HbF) levels and the haplotypes of beta s chromosomes in sickle cell anaemia patients in Nigeria were evaluated. The mean HbF level was 5.9 +/- 3.8% with a range of 0.9-16.7%. 80% of the patients had HbF values below 8% and 94% had HbF levels below 10%. No significant difference in haematological parameters was seen between those with less than 2% HbF and those with greater than 8% HbF. The presence (+) or absence (-) of eight restriction endonuclease enzyme sites within the beta s globin gene cluster (haplotype) on chromosome 11 were mapped. The common haplotype (- - - - + + - +) in 97% of the chromosomes examined closely correlates with the low levels of foetal haemoglobin generally observed in sickle cell patients in the same population.

Hemoglobin chain recombination and the pattern of composition of hemoglobin S and D in heterozygotes.

The pattern of composition of hemoglobin in different heterozygotes for S and D hemoglobins is quantitatively accounted for by the relative rates of combination of the different chains alpha + beta A greater than alpha + beta D greatern than alpha + beta S greater than alpha + gamma. It is suggested that the recombination step may be one of the rate-limiting steps in hemoglobin assembly.