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.