Severe morbidity among children in a trial malaria chemoprophylaxis with pyrimethamine or chloroquine in Ibarapa, Nigeria.

In a controlled trial of weekly malaria chemoprophylaxis with chloroquine and pyrimethamine there were no significant differences in type and frequency of severe morbidity during chemoprophylaxis. Administration of chemoprophylaxis during the current and immediately preceding month was associated with significantly fewer episodes of severe morbidity in the chloroquine and pyrimethamine groups when each was compared with the control multivite group. After chemoprophylaxis had been stopped, significantly more episodes of severe morbidity occurred in the chloroquine group than the control group, but a similar trend in the pyrimethamine group was not statistically significant. In the control group most of the episodes of severe morbidity, including those episodes which were associated with heavy parasitaemia, occurred below the age of 4 years. In contrast, the children who received chemoprophylaxis continued to experience such illness at older ages. The difference between the chloroquine group and the control group in respect of age at time of severe morbidity was statistically significant.

Evidence that circulating lymphocytes act as vehicles or viraemia in measles.

Previously described giant multinucleated cells were observed in phytohaemagglutinin (PHA) cultures of leucocytes from blood samples of 17 (36%) out of 47 children with measles or undiagnosed fever in Ibadan. The giant cells were more readily seen in PHA cultures of purified lymphocyte preparations than in total leucocyte suspensions. It was concluded that the observation indicates in vivo infection of some blood lymphocytes of patients with measles and related infections by syncitium producing virus to manifest the giant cells seen in culture. The practical application of lymphocyte cultures to the laboratory diagnosis of measles is stressed and the concept of circulating lymphocytes contributing to the systemic spread of measles infection is highlighted.

Blood lymphocytes and measles viraemia.

Previously described giant multinucleated cells were observed in phytohaemagglutinin (PHA) cultures of washed leucocytes from blood samples of seventeen (36%) out of forty-seven children with measles or undiagnosed fever in Ibadan. The giant cells were more readily seen in PHA cultures of purified lymphocyte preparations than in total leucocyte suspensions. It was concluded that the giant cells seen in cultures indicate in-vivo infection of some blood lymphocytes of patients with measles and related infections by syncytium-producing virus. The practical application of lymphocyte cultures to the laboratory diagnosis of measles is stressed, and the concept of circulating lymphocytes acting as vehicles for the systemic spread of measles infection is highlighted.

The effect of substance(s) associated with malarial parasites on C3b inactivator.

The effects of a substance or substances associated with malarial parasites on the inhibitory role of C3b inactivator in immune adherence were investigated. The test system involved adherence of immune complexes of complement-bearing sheep erythrocytes and rabbit antibody, using human group O erythrocytes and human renal glomerular tissues as indicators. Malarial antigen and other soluble by-products of the malarial parasites, presumably present in spent culture medium, did not interfere with the inhibitory role of C3b inactivator. However, malarial pigment, both crude and purified, enhanced immune adherence in the presence of C3b inactivator. It is suggested that malarial pigment, by inhibiting the action of C3b inactivator, may play a significant role in the immunopathogenesis of renal lesions associated with malarial infections.

Cytopathology and short-term culture of malignant tumours in Ibadan.

This report is a retrospective review of early studies (1965-70) on the cytology and short-term tissue culture of fresh specimens from 1643 patients under investigation for cancer at the University College Hospital, Ibadan. A total of 580 specimens were positive for malignant cells. The technical procedures are described in some detail and were found to be particularly useful as aid to laboratory diagnosis of 310 childhood tumours. The relative frequency of Burkitt's lymphoma, retinoblastoma, neuroblastoma and Wilm's tumour in the series was 20:1:1:0.5 respectively. Adoption of the technique as part of routine diagnostic service of teaching hospitals of developing countries is recommended.

Range of normal serum immunoglobulin (IgG, IgA and IgM) values in Nigerians.

The serum levels of immunoglobulins G, A and M of 703 apparently healthy Nigerians resident in Ibadan and aged 1-50 years were studied. The differences in values that are related to age, sex and season were also computed. Normal values of the immunoglobulins varied with age and sex. IgG mean values for the different age groups ranged from 688 to 1251 mg/100 ml in the males and from 720 to 1038 mg/100 ml in the females. For the IgA class the mean values ranged from 81 to 211 mg/100 in the males and from 90 to 206 mg/100 ml in the females. Mean values of IgM varied from 65 to 132 mg/100 ml in the males and from 96 to 114 mg/100 ml in the females. There was a general increase in IgG levels with advancing age especially in the first 20 years of life. IgA increased progressively with age from 1 to 50 years. The male IgM levels generally rose with increasing age while there was no significant elevation in female IgM values. Females had higher levels of IgG, IgA and IgM in the first 10-20 years of life after which the levels were either the same or higher in the males. The possible reason for this observation is discussed. A significant seasonal influence on the three immunoglobulin concentrations could not be demonstrated.

Immunological identification of peripheral-blood lymphocytes from patients with lymphoproliferative disorders in Nigeria. I. Acute lymphocytic leukaemia (ALL).

The peripheral-blood lymphocytes of eight consecutively diagnosed cases of acute lymphocytic leukaemia (ALL) in Nigerians seen over a period of 2 years were classified as T, B and Null cells, using mainly sheep-rosetting (for T cells) and EAC-rosetting (for B cells) techniques. The patients' lymphocytes response to stimulation with phytohaemagglutinin (PHA) and basic haematological parameters were also determined. There were three male cases (37.5%), aged 10, 14 and 21 years who had T-cell ALL and one boy (12.5%) aged 10 years with B-cell ALL. The remaining four patients (50%) were two girls aged 6 and 6 1/2 years and two males aged 10 and 21 years who had lymphocytic leukaemia of the Null-cell class. These results from a tropical environment agree with previous findings among Caucasians with respect to the age and sex incidence and predominance of ALL with Null cells.

Immunological identification of peripheral-blood lymphocytes from patients with lymphoproliferative disorders in Nigeria. II. Chronic lymphocytic leukaemia (CLL).

The surface markers for blood T and B lymphocytes in sixteen consecutively diagnosed patients with CLL were sought for. There were twelve females and four males, and their ages ranged from 30 to 70 years. Although the absolute numbers of T and B lymphocytes were increased, the percentage scores as well as mitogenic responses of these leukaemic cells were depressed, and all the patients except one who has T-cell CLL were considered to have Null-cell CLL. This finding suggests that CLL may take an unusual form in a tropical environment, and this may account for the long remissions which often occur.

Lymphocyte subpopulations and antibody levels in immunized malnourished children.

1. The proportions of lymphocyte subpopulations (by rosette tests) and the serum antibody levels (using haemagglutination techniques) were estimated in malnourished and well fed Nigerian children before and up to 21 d after immunization with tetanus toxoid or measles virus vaccine. 2. Significantly diminished (P less than 0.01) mean percentage T lymphocyte levels and considerably higher mean percentage null cell levels were observed in the malnourished children before immunization with either of the vaccines. 3. There was comparable in vivo increases in percentage T lymphocytes in malnourished and control children following the administration of each antigen. 4. The mean percentage B lymphocyte levels were similar in the control and malnourished children before and after the immunization. 5. There was a slight depression in the tetanus antibody levels (P greater than 0.2) but a significant diminution (P less than 0.01) in measles virus antibody concentrations in the malnourished children. 6. Rise in mean percentage T lymphocytes corresponded with the elevation in mean tetanus antibody levels in both malnourished and control children following tetanus toxoid immunization. This was however not the situation in the malnourished children following immunization with measles virus. 7. The observed depressed T lymphocyte number in malnourished children may in practice affect their handling of antigens such as measles virus in vivo.

The occurrence and properties of E rosette inhibitory substance in the sera of malnourished children.

In vitro sheep erythrocyte (E) rosette inhibitory activity was observed in the sera of nine out of 22 (41%) children with kwashiorkor, three of 15 (20%) marasmic children, neither of the two children with marasmic-kwashiorkor and in one of 42 (2%) well nourished control children. Sera of children with kwashiorkor containing the E rosette inhibitory substance did not inhibit in vitro rosette formations by autologous lymphocytes whereas rosette formations by homologous lymphocytes were inhibited. Inhibition of E rosette formation occurred when lymphocytes were pretreated with serum having the inhibitory substance before incubation with sheep red cells, but there was no such inhibition when sheep red cells were pretreated with the same serum before incubation with lymphocytes. The inhibitory substance was observed to be stable at 4 degrees C up to about 1 week and migrated electrophoretically with the alpha-2 globulins. It was digested by papain. It is probable that the E rosette inhibitory substance demonstrated in the present study is attached to markers on T lymphocyte surfaces in some malnourished children thereby making the lymphocytes unreactive in vitro and presumably in vivo as well.

IgG subclass levels in malaria-infected Nigerians.

IgG class and subclass levels were measured in the sera of malaria-infected patients who had high serum antibody titres (greater than or equal to 1 in 5,120) as well as in uninfected controls with low serum malaria antibody titres (less than or equal to 1 in 320). The malaria-infected patients had higher IgG and IgGI subclass levels than the uninfected controls (p less than 0.005). There was a slight diminution in the mean IgG3 concentration in the malaria-infected patients.

Antibodies to Herpesvirus hominis types 1 and 2 in malnourished Nigerian children.

Antibodies to Herpesvirus hominis (HVH) types 1 and 2 were determined by a micro-neutralisation method in 37 children with kwashiorkor, 16 with marasmus, and in 64 well-nourished control children. All the children were aged between 1 and 4 years. The prevalence of antibodies was similar in the two sexes and at different ages. HVH-1 antibodies were present in 51% of children with kwashiorkor, in 44% with marasmus, and in 26% of well-nourished children, reflecting the very poor socioeconomic conditions of malnourished children. HVH-2 antibodies too were present in about 19% of children with kwashiorkor, and in 2% of well-nourished controls; they were absent in marasmic children. It is suggested that HVH-2 infection in malnourished children is facilitated by the communal use of fomites--such as bedclothes and underwear.

Serum levels of immunoglobulin G subclasses in Nigerians.

IgG subclass levels were determined in 128 apparently normal Nigerian subjects aged 6--42 years, using a modified radial immunodiffusion technique. IgG1 constituted the major subclass with about 70% of the total IgG. IgG4 subclass was the least with about 0.5%. The concentrations of IgG2 and IgG3 were 27% and 1.5% of the total IgG respectively. There was no systematic effect of age on all the subclasses. IgG1 and IgG2 levels were higher in females than in males but there were no marked differences in the IgG3 and IgG4 levels between the sexes.

Serum immunoconglutinin levels in healthy subjects, malaria nephrosis and other conditions.

Serum immunoconglutinin (I-K) levels were estimated and compared in 189 normal school children, ninety blood donors, eight-seven nephrotic children, twenty-eight nephrotic adults, twenty-five falciparum malaria children and 126 miscellaneous patients. Low levels (1/32 or less) were recorded in 75.1% of normal school children and 68.9% of blood donors. Similarly 95.4% of nephrotic children and 71.4% of nephrotic adults had low titres. The trend was the same in other disease groups in which 88.0% of falciparum malaria children and 65.1% miscellaneous patients had low titres. The relevance of the I-K levels obtained in the study groups is discussed.

Severe malaria and glucose-6-phosphate-dehydrogenase deficiency: a reappraisal of the malaria/G-6-P.D. hypothesis.

Nigerian children with convulsions and Plasmodium falciparium parasitaemia above 100,000/microliter did not show a decreased frequency of glucose-6-phosphate-dehydrogenase (G.-6-P.D.) deficiency. A re-evaluation of earlier studies has led to the conclusion that clinical evidence of protection against falciparum malaria in G.-6-P.D.-deficient individuals is lacking. Evidence for the possible role of malaria in selecting for G.-6-P.D.-deficient genes consists solely of the geographical association of high frequencies of G.-6-P.D. deficiency with endemic malaria.

The detection of antibodies to hookworm larva in patients by immunofluorescence: a preliminary report.

Using the fluorescent antibody technique 84% of patients with severe hookworm infection and 74% of Nigerian blood donors have detecable antibodies that react with surface antigen of hookworm larvae. On the other hand only 24% of Nigerian medical students and 20% of Caucasians (Canadians) have such antibodies in their sera. It is suggested that while the results of tests on students may be due to the relatively infrequent contact with hookworm the antibody positivity in the Caucasians may be due to cross reaction with other related helminths. The titre of antibody produced in the hookworm infected patients was similar to that of the blood donors but differed from other groups. Lower positivity rates were observed with further dilution of sera in the hookworm infected patients. This may be due to their relative incapacity to produce potent hookworm antibody. Further work on this aspect is required as well as improvement of the specificity of the technique.

Correlation of birthweight with foeto-maternal immunoglobulin, total protein and albumin profile.

Using immunodiffusion and biuret methods, immunoglobulins (GAMD), total proteins and albumin measurements were performed at birth on 100 apparently healthy Nigerian mothers and their babies. Sizeable concentrations of IgG were present at birth even in babies with low birth weights (1360 mg/100 ml). The mean IgG level in babies with low birth weights (2,500 g or less) was significantly lower (P less than 0.05) than in average weight and above average weight babies. The mean maternal and cord IgG levels were approximately equal in all except in the low birth weight babies where the mean maternal level was about 40% higher than the mean cord level. The scatter in IgG values was more pronounced in babies with low birth weights than the others. Mothers with higher IgG levels than in their corresponding babies were most prominent in the 'low birth weight' group. There was no significant difference between the maternal as well as between the cord serum IgA and IgM levels. The mean cord serum IgA and IgM levels were about 4 and 10% respectively of their mothers. Compared with the Caucasians, relatively higher quantities of IgD were found in the Nigerian mothers. Twenty-one percent of the maternal and all the cord sera had no detectable amount of IgD. The mean maternal total proteins though higher than the cord serum proteins, showed no statistical difference. The foeto-maternal serum albumin differential, showed statistical difference when average weight babies and above average weight babies were considered (P less than 0.05) but not with low birth weight babies (P less than 0.2).