The New Zealand Blood Donors' Health Study: baseline findings of a large prospective cohort study of injury

INTRODUCTION

Cohort studies have contributed important scientific knowledge regarding the determinants of chronic diseases. Despite the need for etiologic investigations, this design has been infrequently used in injury prevention research.

OBJECTIVES

To describe the baseline findings of the New Zealand Blood Donors' Health Study, a large prospective study designed to investigate relationships between lifestyle, psychosocial factors, and serious injury due to road crashes, falls, self harm, assault, work, sport, and recreation.

METHODS

Participants were recruited from fixed and mobile collection sites of a voluntary non-profit blood donor program. Baseline exposure data (for example risk taking behaviors, alcohol and marijuana use, sleep habits, and depression) were collected using a self administered questionnaire. Outcome data regarding serious injury will be collected prospectively through computerized record linkage of participants' unique identifiers to national morbidity and mortality databases.

RESULTS

In total, 22 389 participants enrolled in the study (81% response rate). The diverse study population included 36% aged 16-24 years, 20% rural residents, and large variability in exposures of interest. For example, in the 12 months before recruitment, 21% had driven a motor vehicle when they considered themselves over the legal limit for alcohol, and 11% had been convicted of traffic violations (excluding parking infringements). Twelve per cent had seriously considered attempting suicide sometime in their life.

CONCLUSIONS

This is the first, large scale cohort study investigating determinants of serious injury in New Zealand and among the largest worldwide. Preliminary findings from prospective analyses that can inform injury prevention policy are expected within five years.

A prospective cohort study of blood donors: methodological issues in the investigation of injuries and chronic diseases

Blood donors have made important contributions to research, most notably in cross-sectional seroprevalence studies. The proposed New Zealand Blood Donors Health Study is a prospective cohort study of 30,000 New Zealand donors designed to investigate the determinants of common injuries, cardiovascular disease and cancer. While robust from an analytic perspective, the execution of prospective cohort studies in many settings is impeded by methodological, economic and organisational barriers. We examined the operational considerations of implementing a large-scale cohort study at a transfusion centre and evaluated measures taken to optimise data collection procedures. A pilot study of 1,000 participants revealed donor motivation to participate in this research was high (91% response rate). Comprehensive exposure data on lifestyle, behavioural and psychosocial factors were obtained from 95% of participants. Substantial heterogeneity in levels of potential risk factors was noted among respondents. Detailed dietary habit information and a study blood sample were obtained from 67% and 100% of participants, respectively. Study recruitment and baseline data collection was feasible during routine donor visits with minimal interruption to donor centre staff and procedures. We conclude the study design and characteristics of the regional donor program enhance the efficiency and significance of the proposed research.

Clinical usage of intravenous immunoglobulins in Auckland

AIMS

To review the indications for prescription of intravenous immunoglobulin (IVIg), in Auckland and the associated adverse effects.

METHODS

All patients who received IVIg infusions in four major hospitals in Auckland in 1996 were identified from blood bank records. Clinical details were recorded from case notes.

RESULTS

One hundred and thirty-five cases were identified and 131 records were available for review. Hypogammaglobulinaemia (n = 38) and thrombocytopenia (n = 38) were the two most common indications for 44% of Primary hypogammaglobulinaemia accounted for IVIg. the IVIg prescribed. IVIg was only used in one patient with hypogammaglobulinaemia secondary to chronic lymphocytic leukaemia and in one case of graft-versus-host disease. Adverse reactions were noted in 13 cases (10%). Headache (n = 4) and fever (n = 4) were the most commonly recorded side-effects. One patient developed acute renal failure after IVIg infusion. Written consent was documented in 7 patients (5%).

CONCLUSIONS

The indications for IVIg prescription were generally consistent with the recommendations of the Australasian Society of Blood Transfusion. Use of IVIg in haematological conditions other than immune thrombocytopaenic purpura was infrequent. Most of the IVIg infusions were administered uneventfully but some minor side effects were recorded and one significant clinical event may have been causally related to IVIg infusion.

Donor work-up and transport of bone marrow--recommendations and requirements for a standardized practice throughout the world from the Donor Registries and Quality Assurance Working Groups of the World Marrow Donor Association (WMDA)

In October 1995 the World Marrow Donor Association (WMDA) was restructured in order to facilitate its primary function of establishing guidelines in relation to international bone marrow and blood stem cell transplants -- transplants in which the donor is in one country and the patient is in another country. Five new working groups were established -- Donor Registries, Ethics, Quality Assurance, Finances, and Stem Cells. This paper, prepared by members of the Donor Registries Working Group, in consultation with the Quality Assurance Working Group, provides recommendations for the 'donor work-up'. This term covers events that start when the definitive donor has been identified, includes the harvesting (collection) and transportation of the stem cell product and ends when the product reaches the transplant centre. The paper includes examples of the documentation intended to ensure compliance with the recommendations at all key points in the sequence.

Clinical and molecular aspects of Gaucher disease in New Zealand

AIM

To report on the clinical and molecular aspects of Gaucher disease in New Zealand.

METHODS

Patients known to have Gaucher disease were contacted and clinical information was recorded by questionnaire. Blood samples from affected individuals and their families provided DNA material for mutation analysis of disease causing alleles. Patients were assayed for beta-glucocerebrosidase, the enzyme deficiency which causes Gaucher disease.

RESULTS

Twelve of 14 patients and 10 carriers were confirmed by DNA analysis. One asymptomatic individual was diagnosed. Four known mutations (N370S, 1444p, R463c and RecNcIl) and one unknown mutation were found from the 34 disease producing alleles that were identified. Of these, the L444P and N370S alleles were the most common. Most patients exhibited a clinical disorder typical of type 1 Gaucher disease. Two recent patients with severe neuropathic Gaucher disease had died in childhood. All patients showed a deficiency in beta-glucocerebrosidase.

CONCLUSION

Gaucher disease in New Zealand is represented in a small number of non Jewish individuals with varying severity. Identifiable mutations and clinical symptoms aid in expanding the Australasian picture of this well studied disease. Enzyme replacement therapy for these patients has recently commenced in New Zealand.

HLA-B27 polymorphism and worldwide susceptibility to ankylosing spondylitis

HLA-B27 is strongly associated to ankylosing spondylitis (AS) and represents a family of eleven B27 alleles (B*2701-11). Our aim was to analyze the distribution of B27 subtypes by PCR/SSOP and genomic sequencing in a large group of populations (n = 17). 711 B27-positive samples from Caucasoid, Asian, African, Amerindian and Polynesian populations were selected to ascertain transracial gene mapping of the B27 subtypes. 476 of these were AS patients, chosen to investigate the contribution of B27 alleles to AS susceptibility. Some significant new findings have arisen from this study: 1) B*2705 was the predominant subtype in circumpolar and subarctic areas. B*2702 was found to be practically restricted to Caucasian populations, showing a higher frequency in Middle-East (Jews) and North Africa (Arabs/Berbers) groups. 2) B*2703 appears associated with AS in Western Africans. This is of remarkable interest since it was suggested that B*2703 would be negatively disease-associated. 3) Although B*2706 appears negatively associated with AS in Thais, we identified two patients from northern China carrying it. This may be a reflection of a disease heterogeneity and could indicate that more than one pathogenic agent can be involved in AS. B*2709 has been recently described as negatively associated with AS in Sardinians. The molecular changes His114Asp (B*2706) and Asp116His (B*2709) could modify the genetic susceptibility to AS.

Transfusion transmitted Yersinia enterocolitica infection in New Zealand

AIMS

To update and summarise cases of transfusion-transmitted Yersinia enterocolitica infection in New Zealand and to evaluate critically suggested methods to reduce this rare but frequently fatal complication of blood transfusion.

METHODS

Case reports of four recent transfusion-transmitted Y. enterocolitica infections in New Zealand are given and previous reports reviewed. Literature review and evaluation of proposed methods to decrease the incidence of transfusing yersinia contaminated blood.

RESULTS

There have been eight cases of transfusion-transmitted Y. enterocolitica infection in New Zealand in the past five years. Four of the five deaths have been directly caused by the transfusion. This gives a transfusion incidence rate of one:65,000 and a fatality rate of one:104,000 units transfused. This fatality rate is more than 80 times higher than that reported in the United States.

CONCLUSIONS

Why the incidence of transfusion-transmitted yersinia is so high is not clear, since we do not store blood as long as many other countries, particularly the United States. In Auckland, however, the cases came at a time when the number of yersinia isolates from the community is reported to be rising. Many suggestions for the prevention of this problem have been put forward reflecting the fact that there is as yet no perfect solution. Those which are easy to implement and cheap to perform are largely already in place and investigation is continuing into the other alternatives.

Alpha-2-HS-glycoprotein polymorphism in New Zealand Europeans and New Zealand Maori

The polymorphism of alpha-2-HS-glycoprotein (AHSG, alpha 2HS) was analysed in a sample of New Zealanders consisting of 194 New Zealand Europeans and 236 New Zealand Maori. Thin layer polyacrylamide gel isoelectric focusing followed by immunofixation revealed four different AHSG phenotypes in New Zealand Europeans and three different AHSG phenotypes in New Zealand Maori. The AHSG*2 frequency of 0.695 for the New Zealand Maori population was found to be one of the highest reported for any population. AHSG*2 appears to be a useful genetic marker for Maori in anthropological studies.

The genetic affinity of Polynesians: evidence from Y chromosome polymorphisms

Y-linked polymorphisms were studied in a sample of 60 Polynesians, and results were compared with findings from studies on other major population groups. Three previously unreported 49a/TaqI haplotypes were observed, two of which possess a new polymorphic fragment named I2. Frequency data for the 49a/TaqI, XY275, pDP31 and Y Alu polymorphisms indicate that Polynesians have greater affinity to Caucasoids than to African populations. Similar population frequency trends were not observed for the p21A1/TaqI polymorphism, supporting the hypothesis that this polymorphism has arisen more than once.

Entire nucleotide sequence and characterization of a hepatitis C virus of genotype V/3a

The entire nucleotide sequence of a hepatitis C virus (HCV) genome (NZL1) of genotype V/3a was determined from overlapping cDNA clones obtained from a human carrier in New Zealand. It comprised 9425 nucleotides (nt) including a 5'-untranslated region of 339 nt, a single large open reading frame encoding a polyprotein of 3021 amino acids, a 3'-untranslated region of 23 nt, and 3'-terminal poly(U) stretches of variable lengths. The NZL1 genome was compared with 15 HCV isolates of other genotypes for which the full-length sequence has been determined. It differed from them by 31.1 to 34.3% in nucleotide sequence identity and by 24.5 to 29.1% in amino acid sequence identity, confirming the distinction of genotype V/3a from the other isolates.

Identification and genotyping of hepatitis C virus in injectable and oral drug users in New Zealand

BACKGROUND

Hepatitis C virus infections are known to be common in injectable drug users (IDU) both in New Zealand and overseas. Little is known of the hepatitis C genotype frequency in this population.

AIMS

To confirm the high incidence of hepatitis C virus infections in IDU and compare this with the frequency in oral drug users (ODU) as well as identify the pattern of hepatitis C genotypes present.

METHODS

Use was made of an experimental nucleocapsid assay as well as a conventional anti-HCV assay. HCV-RNA was identified using a polymerase chain reaction (PCR) technique and a variation of this method was used for HCV genotyping.

RESULTS

Seventy-four per cent of IDU were reactive for anti-HCV in both types of assay. PCR testing detected several more reactive samples. Dominant genotypes were Types I and V, but Type IV was not detected. Mixed infections were noted in some patients. There was a low frequency of anti-HCV in ODU.

CONCLUSIONS

Hepatitis C virus infections are a problem in IDU in New Zealand, and additional public health measures may be required. The distribution of genotypes of HCV-RNA are similar to those seen in other Western countries.

T cell receptor polymorphisms in Caucasians and Polynesians

The purpose of this study was to find genetic polymorphisms that might be useful in studies of Polynesian-Caucasian racial admixture and Polynesian disease susceptibility. The allele frequencies of six T cell receptor locus RFLP were measured in 73 Caucasians and two Polynesian ethnic groups comprising 86 Maoris and 95 Samoans. The RFLP studied were (locus/enzyme/probe): C alpha/Taq1/Y14, V alpha/Taq1/Y14, C beta/BglII/Y35, C gamma/Pvu II/HGP02, V beta 7/BamHI/V beta 7.4 and V beta 8/Bam HI/V beta 8.1. Racial differences in allele frequency were present with all six RFLP (P < 0.001). The allele frequencies of the V alpha/Taq1/Y14 and the V beta 7/BamHI/7.4 RFLP were similar in the two Polynesian groups, both of which differed from the Caucasians. The 1.4 kb allele of the V alpha/Taq1/Y14 RFLP and the 8.0 kb allele of the V beta 7/BamHI/7.4 RFLP were present in low frequency in both Polynesian groups compared to the Caucasian group, consistent with a gene flow effect. These alleles may be useful in studies of Caucasian-Polynesian racial admixture.

The persistence of anti-hepatitis B surface antibodies to three years of age: is a hepatitis B vaccine booster required?

AIMS

To evaluate the persistence of hepatitis B surface antibodies (anti-HBs) after immunisation in early infancy.

METHODS

The infants were born to low risk European mothers negative for hepatitis B surface antigen (HBsAg). All the children had received 3 doses of 20 micrograms of recombinant DNA hepatitis B vaccine.

RESULTS

One month after the third dose all 92 infants were seropositive. The GMT was 1190 mIU/mL and all but one infant had seroprotective titres above 10 mIU/mL. Three years after the vaccination 91% (59 of 65) children who returned for testing still had measurable anti-HBs titres. The GMT was 32 mIU/mL but 26% (17 of 65) had titres less than 10 mIU/ml. Only one child had serologic evidence of contact with the hepatitis B virus but did not develop the disease.

CONCLUSION

This vaccine is safe and effective for at least 3 years. The long term duration of protection from vaccination in early infancy requires further studies.

Hepatitis C virus infections in oral and injectable drug users

AIM

To assess the frequency of hepatitis C virus antibodies (anti HCV) and exposure to hepatitis B virus in injectable and oral drug users in Auckland.

METHODS

Sera from 110 injectable drug users and 154 oral drug users were tested for anti HCV as well as hepatitis B and D virus markers. Liver function tests were also performed.

RESULTS

73% of injectable drug using persons and 4% of oral drug using persons were positive for anti HCV. Over half of persons with a positive anti HCV result had an abnormal elevation of the liver enzyme alanine aminotransferase (ALT). Total HBV exposure was similar in both injectable drug user and oral drug user groups at approximately 30%, with little difference between ethnic groups. There were no positive results for hepatitis D virus infection.

CONCLUSIONS

Injectable drug users who are anti HCV positive may represent a potential source of HCV infection in the community. An upgraded educational programme, perhaps in conjunction with the needle/syringe exchange programme, may be required to ensure drug users are aware of the risks of HCV infection to both themselves and the community.

Unlinked anonymous monitoring of HIV prevalence at sexually transmitted disease clinics

AIM

To determine the prevalence of HIV infection among patients attending the four sexually transmitted disease (STD) clinics in two metropolitan areas of New Zealand.

METHODS

The population studied comprised everyone who attended between August 1991 and August 1992 because of concern about a possible new episode of an STD and who had a blood specimen taken for hepatitis B (or syphilis) serology. The study involved unlinked anonymous testing of left-over blood specimens, following ethical guidelines that have been proposed internationally.

RESULTS

Among 8478 specimens tested, 23 (2.7 per 1000) were found to be HIV positive. The seroprevalence rates per 1000 among women, heterosexual men, and homosexual or bisexual men were 1.1, 1.3, and 44, respectively. All but five of the infected people were either known to be HIV positive or had an identifiable test during their clinic attendance.

CONCLUSIONS

The seroprevalence rates are similar to those reported from STD clinics in England, and suggest that heterosexual transmission of HIV infection has not yet been extensive in New Zealand.

Plasma and red-cell glycolipid patterns of Le(a+b+) and Le(a+b-) Polynesians as further evidence of the weak secretor gene Se(w)

Monoclonal antibodies and thin-layer chromatography were used to study the unusual erythrocyte Lewis phenotypes found in healthy Polynesians. A single monoclonal anti-Leb reagent 073 (clone LM129) was found which could detect Leb antigen on the Polynesian erythrocytes of samples that were unreactive with various polyclonal and monoclonal anti-Leb reagents. Glycolipid fractions prepared from the plasma and erythrocytes of selected Polynesian samples of red-cell Le(a-b-), Le(a+b-) and Le(a+b+) phenotypes were found to have Leb glycolipids. The Leb antigen in some individuals is so weakly expressed that it is undetectable by routine erythrocyte phenotyping. Unusually large glycolipids bearing the Leb epitope were also found in some Polynesian samples, although the contribution of these novel glycolipids to phenotyping is unclear. The inability to detect Leb by routine methods and the presence of novel structures can be partially explained in terms of the presence of a weak secretor gene Se(w).

A possible relationship between colorectal carcinoma and ABO/Lewis blood groups

The incidence of colorectal carcinoma was compared with the incidence of ABO and Lewis blood groups. The raw data showed the known overrepresentation of the Le(a-b) phenotype, but also suggested an association of colorectal carcinoma with the Le(a-b+) phenotype in group O individuals. When the data were adjusted by taking into account the known loss of Lewis antigens by Lewis-positive patients, this association could be shown to be statistically significant. These results may indicate involvement of the secretory H antigen in colorectal carcinoma.

Autologous blood transfusion in Auckland

AIMS

To review autologous blood collection and transfusion practice in Auckland over the last five years.

METHOD

Records of autologous blood collections were obtained from blood collection centre records and results of transfusions on patients from hospital notes.

RESULTS

One hundred and sixty-four units of blood were collected from 77 patients. Seventy-five percent of the units collected were transfused. Most autologous blood was transfused to private hospital patients. Only 8% of patients required homologous blood.

CONCLUSIONS

There has been a slow increase of autologous blood collection and transfusion in the Auckland area, as well as in the rest of New Zealand. The present risks of homologous transfusion, particularly since the introduction of hepatitis C testing, appear very low. A further expansion of the present autologous blood programme would entail increased expenditure and it is suggested that a critical cost benefit analysis would be useful before the programme is expanded.

Hepatitis C virus (HCV) infections in New Zealand

Preliminary studies of the seroprevalence of hepatitis C antibody (anti-HCV) in selected New Zealand populations, reveal similarities to other Western countries. High rates occur in haemophiliacs and intravenous drug users with relatively low rates in routine blood donors. Unlike hepatitis B virus infections anti-HCV does not appear to be more prevalent in Maoris and Pacific Islanders living in New Zealand. Chronic liver disease is associated with anti-HCV. The frequency of anti-HCV in homosexuals and persons attending sexual disease clinics is higher than that found in blood donors. Further detailed studies of the frequency of anti-HCV in New Zealand populations are now required to extend the present baseline data.

Acute post-transfusion fulminant hepatitis C virus infection: a case report

A 21 year old woman developed acute fulminant hepatitis following a transfusion of hepatitis C virus (HCV) infected blood. The patient received a liver transplant and is now well and HCV antibody negative.

Investigation of Lewis phenotypes in Polynesians: evidence of a weak secretor phenotype

The salivary ABH and Lewis antigens of Polynesians were measured using a standardised red cell agglutination microplate assay and compared with the red cell defined Lewis phenotypes. Salivary ABH substances were detected in almost all saliva samples tested, with low levels (partial secretion) of ABH substances in the saliva from Le(a+b-) and Le(a+b+) individuals. Salivary Leb substance was detected in all Le(a-b+) and Le(a+b+) samples and in almost all Le(a+b-) samples. It is evident from the results obtained that Polynesian red cell phenotypes cannot be used to predict the presence or absence of salivary substances. If the presence of a coding secretor gene is presumed responsible for salivary ABH antigens and salivary Leb antigen expression, then the incidence of a coding secretor gene in Polynesians is 98%. These results indicate that the recessive non-secretor gene is absent or rare in a Polynesian derived gene pool. Two variants of secretor individuals are found among Polynesians, secretors with expression of normal amounts of the product of the secretor gene, similar to Caucasians, and partial secretors with weak expression of the secretor gene products.

The safety and immunogenicity of a recombinant hepatitis B vaccine in neonates

A study to evaluate the safety and immunogenicity of a yeast derived recombinant DNA hepatitis B vaccine (Engerix-B) was conducted in healthy newborn infants born to low risk European mothers negative for hepatitis B surface antigen (HBsAg). The vaccination schedule using 20 micrograms doses was administered intramuscularly at 0, 1 and 6 months. The seroconversion rate was 99% (90 of 91 infants). The geometric mean titer of antibody to hepatitis B was 1259 mIU/mL one month after the third dose of vaccine. Possible side effects reported by the mothers were minor and uncommon. This vaccine is highly immunogenic and safe for use in infants.

Influence of heat treatment on FVIII:C recovery from freeze dried cryoprecipitate

A standard lyophilised triple cryoprecipitate preparation, stabilised by the addition of Synthamin 17, was heat treated at 60 degrees C for 48 hours. The total protein content, factor VIII concentration, and factor VIII recovery were not affected by the heat treatment procedure. Heat treatment did not influence the reconstitution characteristics of the freeze dried preparation and there were no side effects during or after administration. The mean in vivo rise of factor VIII from infused heat treated triple cryoprecipitate was 2.5 (SD 0.9)%/unit/kg with a half life of 13.1 (3.1) hours. These results compare favourably with those obtained using non-heated triple cryoprecipitate. Cryoprecipitate can be heat treated without adversely influencing factor VIII recovery, and the ability to prepare a heat treated cryoprecipitate means that a small pool high yield factor VIII preparation can again be used in routine clinical practice.

Evaluation of monoclonal anti-A reagents by salivary inhibition studies

Ten commercially available monoclonal and polyclonal anti-A reagents were evaluated for use in the test for ABH secretor status after finding unexpected inhibition with a monoclonal anti-A (reagent Z). Two of the available monoclonal reagents were from different batches from the same clone as reagent Z. Those two reagents, as well as reagent Z, appeared to be partially neutralized by salivary substances from group A nonsecretor individuals. This finding suggests that when a saliva inhibition test is done, a nonsecretor control saliva of the same ABO group as the saliva to he tested should be used.

The Le(a+b+) phenotype in Polynesians

The presence of the rare Lewis phenotype Le(a+b+) is reported in various Polynesian groups, including Maoris, Samoans, Cook Islanders, Nuieans and Tokelau Islanders. The phenotype was found in Polynesians of all blood groups and the frequency was significantly increased in group 0 persons. The phenotype was not significantly associated with H reactivity in group A donors and showed no correlation with age or sex.

Posttransfusion hepatitis: a persistent problem

Between 1977-84 the reported frequency of clinically evident posttransfusion hepatitis has halved both nationally and in the Auckland region. This is mainly due to a decrease in the frequency of posttransfusion hepatitis B coincident with widespread introduction of sensitive screening tests for HBsAg. About half the cases of transfusion induced hepatitis are now classified as non A non B hepatitis. A further fall in the reported frequency of posttransfusion hepatitis occurred in 1985-86. Possible strategies to further reduce the low frequency of posttransfusion hepatitis in New Zealand are discussed. Although the problem of clinical posttransfusion hepatitis B or non B appears small, the need to report all such cases and to utilise blood and blood products with care is emphasised.

Use of Fab anti-IgG in phenotyping IgG-sensitised red cells

Previously described methods of phenotyping red cells sensitised with IgG using the indirect antiglobulin test required the dissociation of the coating protein. Based on an entirely different principle, Fab fragments of anti-human IgG (Fab anti-IgG) were used to block the antiglobulin binding sites on cell-bound IgG molecules, removing the necessity to dissociate them from the red cell. Fab anti-IgG was found to be effective in blocking interfering IgG on in vivo and in vitro IgG-sensitised red cells, permitting successful red cell phenotyping. Strongly IgG-sensitised samples which could not be fully neutralised by chloroquine diphosphate (CDP) or blocked with Fab anti-IgG alone could usually be phenotyped using a combination of both these methods. This new procedure may be of use in immunohaematology laboratories.

Absence of HTLV I from New Zealand

Sera from 1,943 individuals from Auckland, New Zealand, were tested for the presence of serum antibodies to human T cell lymphotropic virus I (HTLV I), mainly with an enzyme-linked immunosorbent assay (ELISA) with cell extracts as target antigen. The individuals tested were blood donors and mostly Caucasian, but included indigenous Maoris and representatives of several groups of Pacific islanders now resident in New Zealand. Also included were 37 patients with various hematological malignancies, including seven with T cell leukemias. Although 1% of samples were positive by ELISA, none of these were confirmed as positives by Western blotting. On the basis of these results we consider that it is unlikely that HTLV I infection occurs in Auckland; however, we cannot exclude the possibility that pockets of virus infection may occur in other parts of New Zealand or the South Pacific.

A combination of hepatitis B vaccine and immunoglobulin does not protect all infants born to hepatitis B e antigen positive mothers

In 42 infants of hepatitis B e antigen positive carrier mothers a randomised study of a low dose (5 micrograms) hepatitis B vaccine regimen starting within 24 hours of birth with or without hepatitis B immunoglobulin (0.25 ml/kg) showed that in the vaccine group 72% were antibody positive at the age of one year and in the vaccine plus immunoglobulin group 81%. In the vaccine group four of 18 infants were not protected and in those infants receiving vaccine plus immunoglobulin three of 21 were HBsAg carriers by 12 months of age. Hepatitis B vaccine either with or without concomitant HBIg did not protect all babies born of HBeAg positive mothers, from developing the HBsAg carrier status. Thus for full protection of all infants a more vigorous immunisation programme will be necessary.

Hepatitis delta virus infection: a recently imported disease in New Zealand

In a study of 565 hepatitis B antigen (HBsAg) positive persons from the Auckland region, antibody to the hepatitis delta virus was detected in 38. The largest number were in Samoans (61%) although the infection was present in some other Pacific Islanders. Among HBsAg positive healthy blood donors, antenatal patients and acute hepatitis patients between 3.8 and 4.8% were anti-delta positive; while 28% of chronic hepatitis patients were positive suggesting an association between this disease and delta infection. Some positive results were also found in sera from intravenous drug addicts. By contrast, anti-delta was uncommon in New Zealand born Maoris or Europeans. Delta infection can be detected in some Pacific Islanders, some European immigrants as well as intravenous drug addicts and has the potential to spread in an epidemic form to HBsAg carriers in the general community. Widespread vaccination against hepatitis B is recommended to eventually reduce the number of HBsAg carriers in New Zealand.

A heat-treated factor VIII concentrate prepared by controlled-pore glass adsorption chromatography

Four years' experience with a method for preparing a high-purity, low-fibrinogen, heat-treated factor VIII concentrate is reported. The process, batch adsorption of a cryoprecipitate extract with controlled-pore glass granules, removes 77 percent of the cryoprecipitate fibrinogen, resulting in a final concentrate-specific activity of 0.74 IU factor VIII per mg of protein at a yield of 194 IU factor VIII per kg of starting plasma. Heat treatment of the lyophilized concentrate for 72 hours at 60 degrees C results in less than 10 percent loss of factor VIII activity. This process does not require expensive fractionation equipment, is suitable for small-to medium-scale batch concentrate production and could be adopted by moderately well-equipped regional blood processing laboratories for the decentralized production of a high-quality, heat-treated factor VIII concentrate.