Alloantibodies to human platelet glycoprotein antigens (HPA) and HLA class 1 in a cross section of Nigerian antenatal women.

The prevalence of antibodies to human platelet antigens (HPA) and human leukocyte antigens (HLA) class 1 antigens among Nigerian pregnant women has not been reported in our country. This study was therefore aimed at screening the obstetric population for evidence of alloimmunization due to human platelet and HLA class 1 antigens. One hundred and forty four (144) pregnant women attending the obstetric clinic of Military Hospital, Port Harcourt, participated in the study. Their sera were tested for antibodies to HPA and HLA class 1 antigens using GTI PakPlus solid phase ELISA Kit. The total prevalence rate of antibody production was 60.5% (87 out of 144). Among the positive samples, 60 had platelet glycoprotein specific antibodies (41.7%) and 27 had HLA class 1 antibodies (18.8%). In 39.6% of the pregnant women, both platelet specific antibodies and HLA class 1 antibodies appeared. The prevalence of platelet specific glycoprotein antibodies were obtained as follows: GP 11b/111a 12 (8.3%), GP 1a/11a 35 (20.8%), GP Ib/IX 18 (12.5%) and GP IV 9 (6.3%). The prevalence of each platelet antibody subgroup was obtained as follows: anti-HPA-1a,-3a,-4a (4.2%), anti-HPA-1b,-3b,-4a (4.2%), anti-HPA-30 5a and anti-GP Ib/IX (12.5% each), anti-HPA-5b (8.3%) and anti-GP IV (6.3%). A high prevalence rate of human platelet arid cytotoxic antibodies has been observed in our obstetric population. There is need to establish platelet serology laboratory for the proper antenatal and postnatal management of pregnant mothers in this region.

Anaemia, iron deficiency and iron deficiency anaemia among blood donors in Port Harcourt, Nigeria.

BACKGROUND: There is paucity of information on the effect of blood donation on iron stores in Port Harcourt, Nigeria. The present study was, therefore, designed to assess, using a combination of haemoglobin and iron status parameters, the development of anaemia and prevalence of iron deficiency anaemia in this area of Nigeria. MATERIALS AND METHODS: Three hundred and forty-eight unselected consecutive whole blood donors, comprising 96 regular donors, 156 relatives of patients and 96 voluntary donors, constituted the study population. Three haematological parameters (haemoglobin, packed cell volume, and mean cell haemoglobin concentration) and four biochemical iron parameters (serum ferritin, serum iron, total iron binding capacity and transferrin saturation) were assessed using standard colorimetric and ELISA techniques. RESULTS: The prevalence of anaemia alone (haemoglobin <11.0 g/dL) was 13.7%. The prevalence of isolated iron deficiency (serum ferritin <12 ng/mL) was 20.6% while that of iron-deficiency anaemia (haemoglobin <11.0 g/dL + serum ferritin <12.0 ng/mL) was 12.0%. Among the three categories of the donors, the regular donors were found to be most adversely affected as shown by the reduction in mean values of both haematological and biochemical iron parameters. Interestingly, anaemia, iron deficiency and iron-deficiency anaemia were present almost exclusively among regular blood donors, all of whom were over 35 years old. CONCLUSION: Anaemia, iron deficiency and iron-deficiency anaemia are highly prevalent among blood donors in Port Harcourt, Nigeria. It will be necessary to review the screening tests for the selection of blood donors and also include serum ferritin measurement for the routine assessment of blood donors, especially among regular blood donors.

Sero-epidemiology of transfusion-transmissible infectious diseases among blood donors in Osogbo, south-west Nigeria.

BACKGROUND: Transfusion-transmissible infectious agents such as hepatitis B virus (HBV), human immunodeficiency virus (HIV), hepatitis C virus (HCV) and syphilis are among the greatest threats to blood safety for transfusion recipients and pose a serious public health problem. This cross-sectional study was undertaken with the aim of determining the seroprevalence of HIV, HCV, hepatitis B surface antigen (HBsAg) and syphilis and correlates the findings with sex and age to ascertain the associations, if any, in the occurrence of the pathogens. MATERIALS AND METHODS: HBsAg, antibodies to Treponema pallidum and HCV were determined using Clinotech test strips. Antibodies to HIV types 1 and 2 were screened with Determine and Immunocomb. All the reactive samples were confirmed using enzyme-linked immunosorbent assays. Antibodies to Treponema pallidum were confirmed with a Treponema pallidum haemagglutination test. RESULTS: A total of 1,410 apparently healthy prospective blood donors aged between 18 and 64 years (mean+/-SD, 32.58 +/- 10.24 years) who presented for blood donation at the Ladoke Akintola University of Technology Teaching Hospital Blood Bank, Osogbo were studied. The male:female ratio was 6:1. Of the prospective blood donors, 406 (28.8%) had serological evidence of infection with at least one infectious marker and 36 (2.6%) had dual infections. The overall seroprevalence of HBsAg, HIV, HCV and syphilis was found to be 18.6%, 3.1%, 6.0% and 1.1%, respectively. The highest prevalences of HBsAg, HIV, HCV and syphilis infections occurred among commercial blood donors and those aged 18 to 47 years old, the most sexually active age group. There were no significant associations between pathogens except for syphilis and HIV (p > 0.001). CONCLUSION: The high seroprevalence of blood-borne pathogens among prospective blood donors in Osogbo, Nigeria calls for mandatory routine screening of blood donors for HBV, HIV, HCV and syphilis.

Reference percentiles of hematological and biochemical iron values of blood donors in Port Harcourt, Nigeria.

In a setting where there is no functional blood transfusion service, there is a need to establish reference values which will assist in determining the cut-off values of the donor pool and also to evaluate anemia. Three hundred and forty eight blood donors of both sexes, aged 18 to 62 years were studied in a cross-sectional descriptive study. Four biochemical parameters: serum ferritin (SF), serum iron (SI), total iron binding capacity (TIBC) and transferrin saturation (TS) and four hematological parameters: hemoglobin (Hb), packed cell volume (PCV), total white blood cell count (WBC) and erythrocyte sedimentation rate (ESR), were assessed. The median and percentile ranges (10-90% percentile) of the biochemical and hematological parameters were as follows: SF 46.8 ng/ml (0.0-173.1), SI 85.9 microg/dl (19.7-338.0), TIBC 224.7 microg/dl (60.9-541.4), TS 41.2% (15.3-90.6), Hb 12.9 g/dl (7.74-15.6), PCV 38.0% (22.9-47.0), WBC 4.5 x 10(9)/l (3.0-8.0) and ESR 8.0 mm/h (1.0-24.6). The sex of the blood donor volunteers was found to exert an influence on SF, SI, TIBC and WBC in favor of the female; P<0.001. The age of the blood donors had a significant influence on some of the variables especially the hematological variables such as Hb, PCV and ESR (P<0.001). At a cut-off value of Hb 12.0 g/dl, SF 15.0 ng/ml and TS 16, 10.4 and 6.0% had iron deficiency and iron deficiency anemia respectively in this study population. There is a high percentage of iron deficiency anemia in this donor population and this calls for urgent attention.

Prevalence of antibodies to hepatitis C virus in apparently healthy Port Harcourt blood donors and association with blood groups and other risk indicators.

BACKGROUND: Testing for hepatitis C virus (HCV) is not yet mandatory in blood transfusion laboratories in Port Harcourt, Nigeria, so the current prevalence rate of this infection in our locality is unknown. The aim of this study was to determine the prevalence of HCV among apparently healthy blood donors in our area and also to assess some of the risk factors associated with the infection. MATERIALS AND METHODS: The presence of anti-HCV antibodies was determined in the serum of 300 blood donors in Port Harcourt, Nigeria. A second-generation rapid screening test, the HEP C SPOT HCV assay was used. Initial reactive results were confirmed by repeat testing with UBI HCV EIA 4.0 enzyme immunoassay. The ABO and Rh blood groups of donors were also determined using standard serological procedures. RESULTS: The majority of our blood donor population was constituted of males (88%) and commercial donors (63%). The blood group distribution of the donors was as follows: O RhD-positive (73%), AB RhD-positive. (4.0%), A RhD-positive (10.0%), B RhD-positive (3.0%), O RhD-negative (4.0%), A RhD-negative (3.0%), AB RhD-negative (1.0%) and B RhD-negative (2.0%). Fifteen of the 300 donors were positive for HCV, giving a prevalence rate of 5.0% in this study population. The age group 21-30 years was identified as the highest risk group with 60% of the subjects with HCV infection being in this group, compared to 20% each in the age groups 31-40 years and 41-50 years old. Twelve of the 15 (80%) HCV-positive subjects were commercial donors. The prevalence of HCV was statistically significantly higher among female donors than among male donors (chi2 = 81.000, p < 0.01). With regards to the distribution of HCV-positivity according to blood group, 4.1% of the O RhD-positive subjects, 10% of the A RhD-positive subjects and 25% of the AB RhD-positive were HCV-positive. No cases of HCV-positivity were found among the donors with other blood groups. No statistically significant relationship was found to exist between blood groups and HCV prevalence (p > 0.05). CONCLUSION: There was a moderate prevalence of HCV infection (5%) in apparently healthy blood donors in Port Hartcourt, Nigeria. The prevalence was higher among commercial donors and in donors in the age bracket of 21-30 years of age.

Depression of platelet counts in apparently healthy children with asymptomatic malaria infection in a Nigerian metropolitan city.

Asymptomatic malaria infection is a common feature of malaria endemic regions in the tropics. In this prospective cross sectional survey, involving 240 children aged 1 to 8 years (Boys = 117, Girls = 123; Ratio 1:1.05), the median platelet count was 115 x 10(9)/L (IQR 97.5-190). Thirty-three out of 240 (13.75%) of the children had thrombocytopenia (platelet count < 100 x 10(9)/L). Malaria parasite was found to exert significant reduction in platelet count. This reduction was more pronounced in children under 5 years and also at higher parasite counts. An inverse relationship was established between parasite density and platelet count (y = -0.017x + 96.2, r = -0.2). Thrombocytopenia is not only a feature of acute malaria infection but also that of asymptomatic malaria infection in the tropics and might be a useful indicator of malaria in children.

Comparative analysis of malaria parasite density using actual and assumed white blood cell counts.

AIM: To compare malaria parasite densities, calculated using the white cell counts (WBC) of individual children with a standard WBC count of 8.0 x 10(9)/L. METHODS: In a cross-sectional study, the prevalence of malaria WBCs and malaria parasite densities were estimated in 240 healthy Nigerian children aged 1-8 years. RESULTS: Of 240 children, 75 (31.25%) were infected with malaria, 69 (28.75%) with P. falciparum and 9 (3.75%) with other species. The mean (SD) WBC count was 5.1 (2.0) x 10(9)/L. There was an age-related significant difference in the mean WBC counts (t=2.000, p<0.05), with values higher in the under-5s [5.6 (2.0) x 10(9)/L] than in the > or =5-years group [5.0 (1.8) x 10(9)/L]. No significant difference was observed with regard to gender and malaria infection. The mean (SD) parasite densities of P. falciparum obtained using the assumed value of 8.0 x 10(9)/L [1936 (1119.5)] was significantly higher than the parasite densities estimated using the individual WBC counts [1140 (862.8) for P. falciparum] (p<0.0001). CONCLUSION: Parasite density estimation using the assumed count of 8.0 x 10(9)/L might result in over-estimation of the parasite burden. The WBCs of individual patients should always be estimated when parasite density is required.

Abnormal haemoglobin variants, ABO and Rh blood groups among student of African descent in Port Harcourt, Nigeria.

BACKGROUND: Abnormal haemoglobin variants (HbSS,AS,AC,SC,etc) have been known to be common among blacks. Patients with sickle cell disease are often faced with the risk of alloimmunization from allogeneic blood transfusion. OBJECTIVES: The study was designed to sample students population of African descents for the purpose of updating information on the prevalence of abnormal haemoglobin variants, ABO, and Rh blood groups and compare the results with previously published data. METHODS: Standard electrophoretic and haemagglutination techniques were employed in testing the blood samples. RESULTS: Of the 620 students screened, 80.32% were HbAA and 19.68% HbAS. 22.9% were of blood group A, 17.10% group B, 4.84% group AB and 55.16% group O. 96.77% were Rh.D positive while 3.23% were Rh D negative. Sickle cell gene in homozygous state (HbSS) and other abnormal haemoglobin variants were not encountered in this students population,. Analysis of the students population revealed that 454(73.23%) were females while 166(26.77%) were males. Participants of the age group 26-30 years (35.7%) constituted the majority and in this age group, all blood groups were represented. CONCLUSION: There is a gradual decline in the prevalence of abnormal haemoglobin variants in our black population. The frequencies of ABO and Rh blood groups however appeared to be stable and consistent with previous published data.

An assessment of the clinical utility of routine antenatal screening of pregnant women at first clinic attendance for haemoglobin genotypes, haematocrit, ABO and Rh blood groups in Port Harcourt, Nigeria.

This prospective study was designed to provide the frequencies of the haemoglobin genotypes, ABO and Rh blood groups and their effects on the haematocrit values among pregnant women in Port Harcourt. One hundred and eighty (180) pregnant women at their first clinic attendance and in their first pregnancy (parity - 0) participated in this study. The overall frequencies obtained for ABO and Rh blood groups were: 26.67% for group A, 18.33% for B, 2.22% for AB and 52.78% for O. Rh D positive was 95.56% while Rh D negative was 4.44%. The frequencies of haemoglobin genotypes were 70.00% for HbAA, 29.44% for HbAS and 0.56% for HbSS. HbAC and SC did not occur in this study population. The mean haematocrit value was 34.64%. This was found to be independent of the ABO and Rh blood groups (P > 0.05). On the other hand, haemoglobin genotypes were found to exert significant effects on the haematocrit values (F = 8.01, P = 0.0005). No significant relationship was found to exist between age and the haematocrit values. (F = 0.91, P > 0.05). Since pregnancy in sickle cell disease is associated with morbidity, proper antenatal monitoring and counselling will be necessary to prevent fatal outcomes.