Serum levels were determined in urban Chinese, Malays and Indians and in the forest-residing Orang Asli of age group 11 to 50. There was no difference in the IgM levels in the Chinese, Indians and Malays, but the serum IgG was elevated (p less than 0.05) in the Malays and the serum IgA level (p less than 0.01) in the Indians, when compared to the other two races. In contrast to the three other races there was a significant elevation of all three immunoglobulins in the Orang Asli. The mean immunoglobulin levels of the urban Malaysians are comparable to those reported for Caucasians residing in temperate countries. However, in the Orang Asli, the immunoglobulin levels were higher than observed for populations of the temperate regions but are comparable to the levels reported for several other populations of the tropical regions. Females had higher IgM levels than males in the Chinese, Indian and Malays but in the Orang Asli there was no sex difference in the immunoglobulin levels.
Serum immunoglobulin G, A, M, D and E levels were determined in the forest-dwelling Orang Asli of age group 8 to 64 years. The levels are higher than observed for urban Malaysians and comparable to levels reported for populations residing in the tropics. There was no significant difference in serum levels of all the immunoglobulins studied in both sexes. The elevated serum immunoglobulins levels are discussed in terms of the nature of the immune defence developed in the Orang Asli to contend with the many parasites prevalent in their environment.
A total of 736 sera collected from cord blood babies, children and adults of both sexes and of different age groups in Malaysia were tested using indirect fluorescent antibody technique for Toxoplasma antibodies. The RH strain of Toxoplasma gondii zoites were used as antigen. One hundred and twenty five sera which were reactive at 1:64 or high titres were tested with IgM specific conjugate. Results of the present studies showed that the prevalence of Toxoplasma antibody was highest among the Malays and lowest among children than among adults. The significance of Toxoplasma specific IgM was discussed.
Congenital malaria from Malaysia is reported here for the first time. It occurred in a baby boy born to a 16-year-old primigravida who contracted Plasmodium falciparum infection during pregnancy. She suffered malaria during the later stages of pregnancy and at parturition. The placenta was heavily infested with various asexual stages of P. falciparum. Gametocytes were not seen. Extensive search did not show other species. Cord blood showed very light infection with young trophozoites of P. falciparum. Serological studies using IFA technique showed specific IgG and IgM antibodies to P. falciparum in maternal cord and two early neonatal sera. These serum samples showed lower levels of IgG antibodies against P. vivax and P. malariae, but there were no specific IgM antibodies against these species. The value of specific IgM antibody in the diagnosis of congenital malaria is discussed.
Twenty-one patients with rheumatoid arthritis (RA) were investigated for various immunological parameters, both humoral and cellular. IgG concentration was 1673+/-266 mg/dl, IgM 259+/-108 mg/dl and IgA 302 +/-7 mg/dl. Enumeration of T lymphocytes in peripheral blood revealed a value of 66% with a B cell count of 10%. Additionally, IgG levels, in 5 selected patients, appeared to fall to normal levels in the course of treatament with D-penicillamine. The significance of these findings are discussed.
The IgM-globulin levels were determined for 5,167 cord-sera of apparently normal infants and 281 sera of defective infants aged 4 months and younger. The significant level for IgM-globulin in neonates was found to be 20 mgm/dl (2 SD above mean of the normal) above which the level was regarded as abnormally raised. Significant levels of IgM-globulin were found in 0.2% (11/5, 167) ofnormal neonates and in 40.6% (114/281) of defective infants which is more than 200 times the normal value. Combining the normal and abnormal rates, an overall figure of 23 intrauterine infections per 1,000 live births were obtained for Malaysia. The advantages and disadvantages of the use of serum IgM-globulin elevations for the diagnosis of intrauterine infections were discussed.
110 normal, healthy adults were tested for antibody to hepatitis A (anti-HA) type IgG and 86 (78.2%) were found to be positive. An age-specific prevalence wasfound to be lowest in the lower agegroup and highest in the higher age-group. Out of 24 IgG positive individuals, only one was found to have type IgM. No significant difference in the incidence ofanti-HA type IgG was found between 42 patients in the Urology Unit, General Hospital, Kuala Lumpur and normal individuals (P > 0.1). 15 patients diagnosed as viral hepatitis were investigated for HA V IgG and IgM antibodies. 13 (86.7%) were positive for type IgG. Of this, only five (33%) were positive for the type IgM, suggesting that HA V is the cause of acute viral hepatitis in 33% of cases admitted to hospital as viral hepatitis.
Serum samples were obtained within 3 days of capture from 106 cynomolgus monkeys (Macaca fascicularis) in peninsular Malaysia. Fifty-two monkeys were trapped on the fringes of palm oil estates and 54 in dense primary jungle. Sera were tested for antibodies to hepatitis A virus (HAV) with a commercial radioimmunoassay. Twenty-four animals had detectable serum anti-HAV activity (6 of 52 from palm oil estate sites and 18 of 54 from primary jungle sites). Among monkeys at both sites, antibody prevalence was strongly correlated with animal weight: overall only four of 69 monkeys (6%) weighing less than 2.0 kg had serum anti-HAV antibodies, while 14 of 29 (48%) weighing 2.0 to 3.9 kg, and 6 of 8 (75%) weighing 4.0 kg or more, had serum anti-HAV antibodies. These data suggest that wild cynomolgus monkeys in Malaysian jungles become infected with HAV or an HAV-like virus at a rate comparable to that of humans in the same region, and raise the possibility of a sylvatic cycle for HAV.
During a 6 yr period, 105 (69%) of 153 patients in whom a histological diagnosis of minimal change glomerular disease was made had renal biopsy tissue suitable for immunofluorescence examination. Thirty seven (35%) patients showed glomerular mesangial deposits of IgM. All the patients presented with the nephrotic syndrome. We found no significant difference in age and sex prevalence, presentation, response to therapy and glomerular morphology between IgM positive and IgM negative groups. This study suggests that there is no necessity to categorize IgM positive minimal change glomerular disease as a separate entity.
Toxoplasmosis was found not to be an important cause of intrauterine infection in Malaysia as the rate of toxoplasma-specific IgM in 1,060 congenitally defective Malaysian children, 0 to 4 months old (0.4%) was lower than that in 405 normal children of the same age group (2.0%). A total of 8.2 intra-uterine toxoplasmic infections per 1,000 live births was detected of which one-third (2.7 per 1,000 live births) was overt, manifesting symptoms more of liver damage, than eye or brain damage. A comparison was made with the rates in U.S.A. and Europe. The role of toxoplasmosis in abortion needs to be studied.
The pattern of seroconversion to Epstein-Barr virus (EBV) was determined in 98 Malaysian children aged 2 weeks to 12 years. Maternal IgG antibodies to EBV viral capsid antigen, ranging between 1:10 to 1:160 titer, were found in 70.6 percent of infants less than three months old, and dropped to 26 percent by seven to nine months. Primary infection, as denoted by emergence of EBV-IgM antibody, occurred at 4 to 6 months, and by eight years all children were seropositive. Maternal antibody titers to EBV nuclear antigen were detected in 52.9 percent of infants less than 3 months old, declined to undetectable levels by 4 to 12 months, and then increased to 40 percent by the age of 12 years. The IgA antibody to viral capsid antigen was absent in all but one infant aged one year; the child also had IgG anti-early antigen, The IgG antibody to EBV early antigen were present in 17.7 percent of the infants aged 3 months or less. This seroconversion to EBV in early life explains the absence of infectious mononucleosis in the Malaysian population. The data suggest that a subunit vaccine to protect against EBV-associated diseases, most notably nasopharyngeal carcinoma, commonly observed in Malaysians would have to be administered to infants 6-12 months of age.
A modification of the IgM-capture ELISA which can provide an early diagnosis for dengue infection is presented. The test is technically simple compared to HI and appears to be more sensitive. It has the advantage over HIT for the detection of specific IgM in that it is more sensitive and the reading of the result is not subjective. There is the possibility of the test being able to replace HI and HIT in the future.
An indirect immunoperoxidase test was compared with an indirect fluorescent antibody test and the Weil-Felix OXK test for serodiagnosis of scrub typhus by measuring the rickettsial antigen specific activity of IgG, IgM, and whole globulin. Acute and convalescent sera from 50 Rickettsia tsutsugamushi isolate-positive scrub typhus patients and from 45 febrile patients diagnosed as having diseases other than scrub typhus were tested. The receiver operating characteristic for each test showed that the indirect immunoperoxidase and indirect fluorescent antibody tests were more sensitive and specific than the Weil-Felix test using convalescent and acute as well as paired sera. The indirect immunoperoxidase test showed no cross-reactivity when R. tsutsugamushi antigen was tested against sera collected from patients living outside the scrub typhus-endemic area with diseases other than scrub typhus. The indirect immunoperoxidase and indirect fluorescent antibody tests were comparable in measured response to R. tsutsugamushi, R. typhi, and TT-118 (spotted fever group) antigen. Thus the indirect immunoperoxidase test represents a sensitive, specific, reproducible, and practical semiquantitative test for rickettsial disease diagnosis.