Structure, tissue distribution, and chromosomal localization of the prepronociceptin gene

Nociceptin (orphanin FQ), the newly discovered natural agonist of opioid receptor-like (ORL1) receptor, is a neuropeptide that is endowed with pronociceptive activity in vivo. Nociceptin is derived from a larger precursor, prepronociceptin (PPNOC), whose human, mouse, and rat genes we have now isolated. The PPNOC gene is highly conserved in the three species and displays organizational features that are strikingly similar to those of the genes of preproenkephalin, preprodynorphin, and preproopiomelanocortin, the precursors to endogenous opioid peptides, suggesting the four genes belong to the same family-i.e., have a common evolutionary origin. The PPNOC gene encodes a single copy of nociceptin as well as of other peptides whose sequence is strictly conserved across murine and human species; hence it is likely to be neurophysiologically significant. Northern blot analysis shows that the PPNOC gene is predominantly transcribed in the central nervous system (brain and spinal cord) and, albeit weakly, in the ovary, the sole peripheral organ expressing the gene. By using a radiation hybrid cell line panel, the PPNOC gene was mapped to the short arm of human chromosome 8 (8p21), between sequence-tagged site markers WI-5833 and WI-1172, in close proximity of the locus encoding the neurofilament light chain NEFL. Analysis of yeast artificial chromosome clones belonging to the WC8.4 contig covering the 8p21 region did not allow to detect the presence of the gene on these yeast artificial chromosomes, suggesting a gap in the coverage within this contig.

Ancient, highly polymorphic human major histocompatibility complex DQA1 intron sequences

A 438 basepair intron 1 sequence adjacent to exon 2 in the human major histocompatibility complex DQA1 gene defined 16 allelic variants in 69 individuals from wide ethnic backgrounds. In contrast, the most variable coding region spanned by the 247 basepair exon 2 defined 11 allelic variants. Our phylogenetic human intron 1 tree derived by the Bootstrap algorithm reflects the same relative allelic relationships as the reported DQA1 exon 2 tree [Gyllensten and Erlich, Hum Immunol 36:1-10, 1989]. Thus 3' DQA1 intron 1 and exon 2 have cosegregated since divergence of the human races. Comparison of human alleles to a Rhesus monkey DQA1 first intron sequence found only 10 nucleotide substitutions unique to Rhesus, with the other 428 positions (98%) found in at least one human allele. This high degree of homology reflects the evolutionary stability of intron sequences since these two species diverged over 20 million years ago. Because more intron 1 alleles exist than exon 2 alleles, these polymorphic introns can be used to improve tissue typing for transplantation, paternity testing, and forensics and to derive more complete phylogenetic trees. These results suggest that introns represent a previously underutilized polymorphic resource.

DPB1 locus PCR-RFLP typing of the fourth Asia-Oceania Histocompatibility Workshop cell panel reveals a novel DPB1 allele

DPB1 locus typing of the 155 cell 4AOHW panel was performed using a PCR-RFLP method. Ambiguity of allele assignment was resolved by amplification using sequence-specific primers. Of the 150 cells for which typings were achieved, three exhibited unusual restriction enzyme fragment patterns, suggesting the possibility of novel DPB1 alleles. Sequence analysis revealed one allele present in the currently reported 46, one novel allele (4AOHW/107) not present among the 46, and one from a non-human primate which is being investigated. Twenty-six (26) of the 34 10IHW cells have been studied previously by cDNA RFLP, and strong haplotypic associations have been demonstrated between DPA1 and DPB1 locus alleles. It is proposed that exploitation of intron polymorphisms making haplotypes will be an integral part of future DPB1 typing as a "first-pass' stratification process to minimize the requirement for sequence-based methods to definitively assign DPB1 alleles.

Strategy for definition of DR/DQ haplotypes in the 4AOHW cell panel using noncoding sequence polymorphisms

Our previously described intron-based DQA1-typing method provides 11 allelic and suballelic groups, including the eight alleles encoded at the second exon. Concurrent testing for the presence of the DRB3, DRB4, and DRB5 loci and the Rsa I pattern of the DRw52 group simplifies the typing requirements for allele assignment at the highly polymorphic DRB1 locus. The DRB1-allele-shortlisting process relies on known DR/DQ haplotypes. In addition to reducing the testing requirements for definitive DRB1 allele assignment, this strategy allows inference of the DR/DQ haplotype and assists in recognition of novel and/or unusual associations.

HLA-DQA1 allele and suballele typing using noncoding sequence polymorphisms. Application to 4AOHW cell panel typing

HLA-DQA1 typing of the 4AOHW cell panel is presented using a novel strategy that exploits both intron and exon polymorphisms. Intron sequences adjacent to the variable HLA-DQA1 second exon exhibit stable polymorphisms that are specific for locus alleles and certain suballelic DR/DQ haplotypes. A PCR-RFLP method has been developed that is based on amplification of a 780-bp segment extending from intron 1 through exon 2 to intron 2. Stable sequence polymorphisms provide restriction enzyme sites and confer mobility variations detected on polyacrylamide minigel electrophoresis. Direct band comparison of amplified products and restriction fragments with known standards facilitates pattern comparison, obviating the requirement for accurate molecular weight determination. This method, using only two enzymes, identifies a total of 11 allelic and suballelic groups, including all eight DQA1 alleles encoded at the second exon.

Chromosomal mapping of A1 and A2 adenosine receptors, VIP receptor, and a new subtype of serotonin receptor

cDNA clones encoding four new receptors of the G-protein-coupled receptor family were obtained by selective amplification and cloning from thyroid cDNA and termed RDC1, RDC4, RDC7, and RDC8. RDC7 and RDC8 have recently been identified as A1 and A2 adenosine receptors, respectively. These cDNAs were utilized for chromosomal in situ hybridization to establish the genomic location of the corresponding genes in man. The results indicate that human RDC1, RDC4, RDC7, and RDC8 are in regions 2q37, 1p34.3-1p36.3, 22q11.2-22q13.1, and 11q11-11q13, respectively.

Selective amplification and cloning of four new members of the G protein-coupled receptor family

An approach based on the polymerase chain reaction has been devised to clone new members of the family of genes encoding guanosine triphosphate-binding protein (G protein)-coupled receptors. Degenerate primers corresponding to consensus sequences of the third and sixth transmembrane segments of available receptors were used to selectively amplify and clone members of this gene family from thyroid complementary DNA. Clones encoding three known receptors and four new putative receptors were obtained. Sequence comparisons established that the new genes belong to the G protein-coupled receptor family. Close structural similarity was observed between one of the putative receptors and the 5HT1a receptor. Two other molecules displayed common sequence characteristics, suggesting that they are members of a new subfamily of receptors with a very short nonglycosylated (extracellular) amino-terminal extension.

Alternative splicing may be responsible for heterogeneity of thyroglobulin structure

During the cloning of the bovine thyroglobulin cDNA, the restriction map of one of the recombinant plasmids was in disagreement with that of the full-length double-stranded thyroglobulin cDNA. When compared to the bovine Tg mRNA sequence, this cDNA clone exhibits a 333-nucleotide deletion which corresponds precisely to 2 exons of the Tg gene. It is thus likely that alternative processing of the premessenger RNA is at the origin of the deletion. The presence of giant introns in the vicinity of the dispensable exons may also reflect some error level in the splicing mechanism. Together with previous results the alternative splicing described in this study indicates that alternative processing of the Tg transcripts may be at the origin of thyroglobulin isoforms.

A nonsense mutation causes hereditary goitre in the Afrikander cattle and unmasks alternative splicing of thyroglobulin transcripts

The hereditary goitre of Afrikander cattle is an autosomal recessive disease characterized in homozygotes by the production of abnormal thyroglobulin (Tg) and the coexistence in the thyroid of normal-sized 8.4-kilobase (kb) Tg mRNA with a misspliced 7.3-kb message having lost exon 9. We have cloned and sequenced the cDNA segment corresponding to the abnormal exon 8-exon 10 junction and the relevant genomic DNA region. The mutation responsible for the disease is a cytosine to thymine transition creating a stop codon at position 697 in exon 9. The original reading frame is maintained in the 7.3-kb mRNA, which, as it lacks the mutated exon, is translatable into a potentially functional protein. This puzzling phenotype in which a mutated exon is apparently removed selectively from transcripts by alternative splicing leads us to suggest that the 7.3-kb transcript could be present in normal animals. Using a sensitive oligonucleotide hybridization assay, we have demonstrated that a 7.3-kb mRNA lacking exon 9 does exist in normal thyroids as a minor mRNA species. As it is fully translatable, the 7.3-kb mRNA is expected to be more stable than the normal-sized 8.4-kb message. This probably accounts for the higher proportion of 7.3-kb transcript found in the goitre.

Primary structure of bovine thyroglobulin deduced from the sequence of its 8,431-base complementary DNA

In mammals, an adequate supply of thyroid hormones is essential for normal growth and neurological development. The biosynthesis of thyroid hormones involves an iodinated precursor protein, thyroglobulin, which may be considered an extreme example of a pro-hormone. Thyroglobulin is a dimeric glycoprotein of relative molecular mass (Mr) 660,000 (660K), which is secreted by the thyrocyte and stored in the lumen of the thyroid follicle. The hormonogenic reaction is extracellular, and involves iodination of tyrosyl residues of thyroglobulin and the intramolecular coupling of a subset of these into thyroxine (T4) and triiodothyronine (T3), which remain part of the polypeptide chain. Secretion of hormones results from the endocytosis of thyroglobulin followed by its complete hydrolysis in lysosomes. Considering that the maximum yield of hormones is approximately 6-8 per 660K protein, the whole process is apparently wasteful. However, the efficiency of thyroglobulin as a thyroid hormone precursor is extremely high when the supply of iodine is short; in such conditions, almost all the iodine incorporated is found in iodothyronine. Hence it is suggested that the thyroglobulin structure has evolved to allow for the preferential and efficient iodination and coupling of the hormonogenic tyrosines. Here we report the complete primary structure of bovine thyroglobulin, derived from the sequence of its 8,431-base-pair complementary DNA. The 2,769-amino-acid sequence is characterized by a pattern of imperfect repeats derived from three cysteine-rich motifs. Four hormonogenic tyrosines have been precisely localized near the amino and carboxyl ends of the protein.

Presence of hormonogenic and repetitive domains in the first 930 amino acids of bovine thyroglobulin as deduced from the cDNA sequence

The sequence of the first 2831 nucleotides of bovine thyroglobulin mRNA has been determined from the analysis of a cDNA clone. Following a 41-nucleotide 5' untranslated sequence, a single open-reading frame encoding 930 amino acids was observed. This corresponds to the aminoterminal third of thyroglobulin, preceded by a putative signal peptide of 19 amino acids. The protein sequence was found to be essentially made of the sevenfold repetition of a 60-amino-acid-long building unit, interrupted at fixed positions by unrelated segments of variable length. The presence of an internal homology within the repetitive unit itself suggests that the 5' region of the thyroglobulin gene has evolved from the initial duplication of a relatively short sequence, followed by the serial duplication of the resulting unit. The tyrosine residue at position five has been assigned an important hormonogenic function [Mercken, L., Simons, M.-J. and Vassart, G. (1982) FEBS Lett. 149, 285-287]. This residue is flanked by sequence elements related to the repeated unit, suggesting that the hormonogenic domain evolved also from the basic ancestor sequence.

Identification of hormonogenic domains in the carboxyl terminal region of bovine thyroglobulin

A segment of 986 nucleotides corresponding to the 3' end of the 8.5 kb bovine thyroglobulin (Tg) mRNA has been sequenced. An open reading frame of 302 codons was found, ending with TGA and preceding an 80 nucleotide long 3' untranslated sequence. The encoded protein sequence provided the first data on the carboxyl terminal portion of Tg. Lysine was identified as the last residue. Comparison of the amino acid sequence with that of peptides known to contain thyroid hormones in the mature protein, lead to the identification of three regions involved in thyroid hormone formation. Two closely linked thyroxine- forming sites were found 182 and 196 amino acids from the carboxyl terminus respectively. The antepenultimate amino acid of the protein corresponded to the recently described triiodothyronine-forming site. Together with the previous localization of the main thyroxine-containing peptide at the amino terminus, the present results provide a map of all hormonogenic sites identified to date in Tg.

HLA and nasopharyngeal carcinoma in Chinese--a further study

This paper reports the results of 8 years of HLA typing of newly diagnosed nasopharyngeal carcinoma (NPC) patients among Chinese in Singapore, and compares the HLA profile of NPC cases with that of the normal Chinese population. Earlier results had indicated an association with A2 and BW46, but the heterogeneity of the earlier case series, which contained a proportion of long-term survivors, obscured other aspects of the relationship. In this paper, the risk associated with A2 (relative risk = 1.5) and BW46 (relative risk = 1.9) is confirmed, showing a much higher relative risk in the presence of both antigens, and a risk is also demonstrated for B17 (relative risk = 2.1). Relative risks of less than unity are observed for AII (relative risk = 0.5) and B13 (relative risk = 0.5). Data from family studies indicate the importance of the haplotype A2.BW46 in determining risk for NPC.

The 5'-end of bovine thyroglobulin mRNA encodes a hormonogenic peptide

The sequence of 370 bases at the 5'-end of bovine thyroglobulin mRNA has been determined. A 41 base untranslated segment was found preceeding the ATG initiator codon. It is followed by an open reading frame providing the first data on thyroglobulin primary structure. Analysis of the amino acid sequence demonstrated the presence of an 18 residue hydrophobic segment representing a putative signal peptide. Comparison of the amino terminal sequence of thyroglobulin with that of peptides known to contain thyroid hormones [7,8] demonstrated that the first tyrosine in native thyroglobulin is mainly found as thyroxine in the mature iodinated protein [8]. Our results clearly identify the amino-terminal region of thyroglobulin as an important hormonogenic domain of the protein.

Gm allotypes and multiple sclerosis

Immunoglobulin allotypes (Gm) were analysed in 40 multiple sclerosis (MS) patients and the distribution of phenotypes compared to that in 1220 healthy controls. The frequencies of GM(1) and Gm(1, 2) are significantly increased inthe patients suggesting that the presence of the Gm3;5, 13, 14 haplotype confers a resistance to the development of MS.

Serum HLA typing

This paper establishes that HLA antigens can be detected in serum by lymphocytotoxicity inhibition. A score system is described which enables the degree of cytotoxicity inhibition to be quantitated. The following HLA antigens have been detected: A1, A2, A3, A11, Aw24, B5, B7, B8, B27, Bw35 and B40. It has not been possible to detect HLA-B12.

HLA antigen in Chinese patients with hepatocellular carcinomas

One hundred and fourteen Chinese patients with hepatocellular carcinomas (HCC) were studied for alpha-fetoprotein (AFP), hepatitis B surface antigen (HBsAg), anti-HBsAg, and HLA markers. Younger patients with HCC (less than 60 yr old) were more significantly associated with elevated serum AFP (P less than 0.0001) and serum HBsAg (P less than 0.0001) than were older (greater than or equal to 60 yr old) patients. A strong correlation existed between serum AFP and HBsAg among the patients (P less than 0.0001). Of 27 AFP-negative patients, 15 (55.6%) had HLA-B15 compared to 53 of 238 (22.3%) healthy controls (corrected P less than 0.003, relative risk = 4.4). The frequency of HLA-B15 was even higher in the AFP-negative plus HBsAg-negative subgroup (61%). AFP-negative patients also had a significant lack of blood group A.

Frequencies of Gm and Km allotypes in the population of Singapore, Sri Lanka and Punjabis in North India

Serum samples from Sinhalese subjects, from Punjab and from Singapore have been studied. The Gm phenotypes found are very numerous and we can observe some similarities concerning the Gm gene frequencies between the Singapore Indians with the Indians of North India, and with the Sinhalese. In contrast, Gm gene frequencies found among Chinese and Malays from Singapore are quite different from those found among Indians of Singapore. Our results here are very similar to those obtained in Malaya studies.

Histopathology of nasopharyngeal carcinoma: correlations with epidemiology, survival rates and other biological characteristics

A total of 363 cases of nasopharyngeal carcinoma (NPC) in Singapore were classified into squamous cell carcinoma (SCC; 73 cases), non-keratinizing carcinoma (NKC; 178 cases) and undifferentiated carcinoma (UC; 172 cases). Possible biological differences between these histologic types and between tumors with and without lymphocytic infiltration were investigated by correlations with survival rates and with selected epidemiologic, immunovirologic, and immunogenetic data on the disease. The 5-year survival rates following radiotherapy were 25.3% for all cases and 58.8% for tumors restricted to the nasopharynx. The 5-year survival rate for SCC was poorer than for the combined NKC and UC groups (p less than 0.05). The 3-year survival rate was better for tumors with lymphocytic infiltration (p less than 0.05), but there were no differences in the 5-year survivals. The survival rates were better in females (p less than 0.01) and in the younger age groups (p less than 0.01). There were no significant correlations between histopathology of NPC and the distributions of cases by age, sex, HLA antigen profiles, or cell-mediated immune status. Squamous cell carcinoma was associated with lower levels of antibodies to the Epstein-Barr nuclear antigen (p less than 0.05), but there were no differences with respect to antibodies against other EBV related antigens. These findings support the view that SCC, NKC, and UC of the nasopharynx, as defined in the WHO classification, are variants of a fairly homogeneous group of neoplasms in the Singapore population.

Geographic tongue--a manifestation of atopy

One hundred patients with geographic tongue have been studied for evidence of an association with atopy. There was a significantly high frequency of personal and/or family history of asthma, eczema and hay fever amongst the patients when compared to a control population. A raised total serum IgE( greater than or equal to 200 u/ml) was significantly more frequent in patients compared to a control population. These findings confirm the impression that in some patients geographic tongue is a sign of atopy.

Detection of alpha-fetoprotein by supplementation counterimmunoelectrophoresis (CIE)

A simple, inexpensive and sensitive method of detecting alpha-fetoprotein (AFP) by supplementation CIE assay is described. The method detects AFP at concentrations in the region of 20 ng/ml.

Histocompatibility leukocyte antigen patterns and nasopharyngeal carcinoma

Incidence patterns indicated the prominent role of genetic factors in this type of cancer. A histocompatibility leukocyte antigen (HLA) profile of A2 and B-locus antigen, Singapore 2 (Sin 2), was identified. An association between these genes and increased risk for nasopharyngeal carcinoma (NPC), was confirmed. The risk was restricted to the "co-occurrence" of A2, B-Sin 2, suggesting that the genotype predisposing to the development of NPC was the A, B-Sin 2 haplotype. Similar associations were found to exist in Malaysian and Hong Kong Chinese so the A2, B-Sin 2 phenotype is a feature common to Asian Chinese in at least three locations. Preliminary HLA studies of medium NPC incidence in Tunisians and Malays indicated that patients with NPC of both ethnic types have altered HLA antigen profiles. If the findings of a locus-B antigen deficit in Tunisians and the role of A9 with B-locus antigens in Malays can be confirmed and clarified, the histocompatibility genetic hypothesis of NPC predisposition would be substantially strengthened.

Immunogenetic aspects of nasopharyngeal carcinoma. V. Confirmation of a Chinese-related HLA profile (A2, Singapore 2) associated with an increased risk in Chinese for nasopharyngeal carcinoma

Histocompatibility locus A typing of 43 Malaysian Chinese and 51 Hong Kong Chinese patients with nasopharyngeal carcinoma (NPC) confirmed the association between the occurrence of A2-Sin 2 and the increased risk for NPC that was previously demonstrated in Singapore Chinese. The results support the previous interpretation that the histocompatibility locus A genotype of importance in NPC predisposition is the A2-Sin 2 haplotype. The histocompatibility locus A-linked, genetically determined NPC risk is common to Asian Chinese from at least three geographic locations.

Total body irradiation with 8 MeV X-rays in generalized malignant disease

The authors describe their experience with total body irradiation (TBI) with 8 MeV-x rays in the treatment of disseminated tumors. With a dose of 125 rad, given three times with 2-week intervals, some objective remissions (6/26) were obtained, especially in patients with lymphomas. For solid tumors only subjective improvement could be achieved. The side-effects were acceptable. The authors came to the conclusion that total body irradiation may be an alternative to chemotherapy for certain cases of generalized cancer.

Immunogenetic aspects of nasopharyngeal carcinoma. IV. Increased risk in Chinese of nasopharyngeal carcinoma associated with a Chinese-related HLA profile (A2, Singapore 2)

The results of this study of 110 Singapore Chinese with nasopharyngeal carcinoma (NPC) and 91 controls confirmed the association between the occurrence of HLA antigen Singapore 2 (Sin2) and NPC in the Chinese population, and indicated that their increased risk for NPC was confined to the joint occurrence of Sin 2 and A2 antigens. These findings suggested that the genotype of importance in susceptibility to NPC is the A2-Sin 2 haplotype.

Impaired general cell-mediated immune functions in vivo and in vitro in patients with nasopharyngeal carcinoma

General cell-mediated immune (CMI) functions in NPC patients were investigated by the in vivo Mantoux and in vitro lymphocyte response to PHA assays. Thirty-eight (50%) of 76 untreated NPC patients were hyporesponsive in the Mantoux assay compared to 27 (25%) of 110 control patients. Forty-three (65.2%) of 66 untreated NPC patients also showed lymphocyte hyporesponsiveness to PHA compared to 15 (15.5%) of 97 control patients. Combined deficiencies were observed in 35 (42.2%) of 83 NPC patients compared to only 2 (3.3%) of 61 control patients. No difference in the frequency of immunodeficiency was observed between "early" and "late" disease patients. CMI functions of treated "remission" NPC patients were found to be impaired to the same extent as those of untreated NPC patients.

Levamisole augmentation of lymphocyte hyporesponsiveness to phytohaemagglutinin in patients with pulmonary tuberculosis

Levamisole has been shown to augment the in vitro responsiveness of lymphocytes to PHA stimulation. The response of lymphocytes of 14 (42%) of 33 patients with pulmonary tuberculosis was augmented by levamisole. Augmentation was observed in 9 (64%) of 14 PHA hyporesponsives lymphocytes and in 5 (26%) of 19 normo-responsive lymphocytes.

Blood group genetic studies in an urban Chinese population

The distribution of the blood group systems ABO, Rhesus, MNSs and P was studied in all or some of 1,007 Singapore Chinese, ABO gene frequencies were found to be consistent with previous studies and did not vary significantly between dialects. An individual of phenotype A2B was detected although the population showed no other evidence for the A2 gene. The possible significance of this observation in terms of weak H alleles in the population is discussed. The frequencies of the MNSs genes are consistent with previous studies. Two subjects appeared to lack the NA component of the N antigen. The frequency of the R1 gene of the Rhesus system was lower than has been detected previously and may relate to dialect differences. No examples of the CW antigen were detected. The P blood group distribution appears to be subject to regional variation. It is concluded that classification of Chinese into dialect groups is a useful way of assessing genetic heterogeneity.

Serum IgE levels in normal subjects and allergy patients among the Chinese in Singapore

Serum IgE was determined in four groups of Singapore Chinese consisting of 292 normal subjects, 15 patients with atopic dermatitis, 39 with drug allergy and 14 with bronchial asthma. The results were compared with the findings of similar groups in western countries. In the normal subjects the range and means (numerical and geometrical) of serum IgE were four to seven times higher in the Singapore Chinese than reported in the western countries. However, the circulating levels in atopic dermatitis and bronchial asthma patients were comparable. In drug allergy moderate IgE elevation was noted. The serum IgE levels of the normal subjects and patients with atopic dermatitis and bronchial asthma were markedly lower than those found in nearby Papua New Guinea. The significance of these observations is discussed.

Transfusion of hepatitis B immune complex-containing blood in high HBV prevalence populations

In several countries where there is a high prevalence of HBV the risk of PTH has been investigated. One study demonstrated that HBV immunity provided protection against infection following transfusion of HBs Ag-postive blood in that a higher proportion of immune recipients failed to develop, or developed only transitory, HBs antigenemia, Forty (61 per cent) of 66 recipients who received HBs Ag positive (IAHA) units developed hepatitis, which was subclinical in 37 (93 per cent) of the 40. Six recipients of HBs Ag-containing units had HBs Ag in the pre-transfusion serum. In four, HBs Ag disappeared in the early post-trasfusion period, and anti-HBs was detected within days, persisting for the duration of the study. The mechanism of this change in HBV immune status is unknown but it may be related to the existence of HBs Ag immune complexemia detectable by radioelectro-complexing in approximately 80 per cent of Hbs Ag-positive blood donors. The phenomenon of apparent "cure" of the HBs antigenemic state warrants further attention.

Immunodeficiency to hepatitis B virus infection and genetic susceptibility to development of hepatocellular carcinoma

The high frequency of hepatitis B antigen (HBsAg) in hepatocellular carcinoma (HCC) patients has led to the hypothesis that immunoresponsiveness to hepatitis B virus (HBV) may be deficient in some patients, and that the immune response deficiency may have a genetic basis. Radioelectrocomplexing (REC), a radioimmunoassay in gel based on the principle of counterimmunoelectrophoresis (CIE), has been used to identify four HBV immune status subgroups: 1) HBsAg +ve/HBsAb +ve; 2) HBsAg +ve/HBsAb -ve; 3) HBsAb -ve/HBsAb +ve; 4) HBsAg -ve/HBsAb -ve/HBsAb -ve. These subgroups comprise 2, 6, 70, and 22 percent, respectively, among blood donors, and 32, 19, 23, and 26 percent, respectively, among HCC patients. Although the HBV exposure rates in the two groups were similar, the immune complexemic rates and HBs antigenemic rates were significantly higher in HBB patients than in the blood donors. It is proposed that the failure of termination of HBV infection revealed by these high rates reflects an immunodeficiency state characterized by an inability to produce high-avidity HBsAb. The immunodeficiency might have a primary genetic basis, or it might be secondary to the immunodepressive effects of concurrent viral or parasitic infections.

Probable identification of an HL-A second-locus antigen associated with a high risk of nasopharyngeal carcinoma

An HL-A antigen profile comprising an increased frequency of HL-A2 and undetectable second-locus antigen(s) in Chinese patients with nasopharyngeal carcinoma (N.P.C.) has been reported. To investigate whether the deficit of second-locus antigen(s) had a genetic basis, sera from parous women in Singapore were screened for anti HL-A activity corresponding to the second-locus "bland". A second-locus (Singapore-2) was identified which seems to be associated with a high risk of N.P.C.

Hepatitis B antigen, antigen subtypes, and hepatitis B antibody in normal subjects and patients with liver disease

The relative sensitivities of counterimmunoelectrophoresis (CIE) and haemagglutination assays for the detection of hepatitis B surface antigen (HB(s)Ag) and antibodies (anti-HB(s)) were compared. Twelve scientists from ten countries in Asia, Africa and the Pacific region participated in the study. The participants provided serum samples from 15 953 subjects comprising patients with acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC), as well as blood donors and other normal individuals. For the detection of HB(s)Ag in a reference panel serum, immune adherence haemagglutination (IAHA) was slightly more sensitive than passive haemagglutination inhibition (PHI); CIE was the least sensitive. Mean HB(s)Ag frequencies in patients with acute hepatitis, chronic hepatitis, cirrhosis, and HCC were significantly higher than in healthy controls. Passive haemagglutination (PHA) was more sensitive than CIE for the detection of anti-HB(s). The frequency of anti-HB(s) in patients with HCC was significantly lower than that in the other groups. Mean anti-HB(s) frequencies in patients with acute hepatitis, chronic hepatitis, and cirrhosis were not significantly different from that in normal subjects. Subtyping of HB(s)Ag was performed by PHI. Among asymptomatic carriers the predominant HB(s)Ag subtype in northeast Asia was adr.In India, ayw predominated in carriers, with the demarcation between adr and ayw occurring west of Burma. In West Africa the only subtype detected was ayw, but in East Africa the majority subtype was adw. The r subtype was found only in Asian populations east of India and in Western Pacific populations. In Papua New Guinea all four subtypes were identified. With one possible exception, the subtypes of HB(s)Ag-positive patients with liver disease reflected the predominant type in each geographic location.