Bone marrow transplantation in the rat. B lymphocyte activation in acute graft-versus-host disease.

We have isolated the white cells from the bone marrow, spleen, and blood of a rat recipient of a bone marrow allograft and the inflammatory leukocytes from the recipient skin, lung, gut, and liver (the parenchymal target organs for acute graft-versus-host disease (aGVHD)) and compared the number of immunoglobulin-synthesizing and releasing cells in these cell populations to corresponding compartments of a syngeneic graft recipient. Bone marrow transplantation was associated in the early phase with marked immunoglobulin production in the cells of bone marrow, spleen, and blood of the allograft recipient; as, however, a similar response occurred in the syngeneic graft recipient we conclude that this is related to reconstitution rather than to aGVHD. Later, during aGVHD, the number of immunoglobulin releasing cells decreased significantly in the spleen and bone marrow of the allografted animal. In clear contrast, in the liver--but not in skin, lung, or gut--very few immunoglobulin-releasing cells were observed in the syngeneic graft recipient, whereas in the allograft recipient a very strong and significantly higher immunoglobulin synthesis and release was seen coinciding with the inflammatory episode of aGVHD in the liver.

Characteristics of human mononuclear cell fractions separated on the basis of theophylline sensitivity of E rosette forming ability.

T lymphocytes may be separated into theophylline-sensitive (Tsens) and theophylline-resistant (Tres) fractions based on their loss or retention of ERFC-forming ability after incubation with 3 mM theophylline. It has been claimed that Tsens cells have a predominant suppressor function, whilst Tres cells have mainly helper activity. We have studied the sensitive and resistant fractions to ascertain their degree of homogeneity with regard to putative markers for helper and suppressor function. Incubation with theophylline caused no significant change in the expression of OKT3, OKT4, OKT8, and OKM1 antigens. Compared to Tsens, Tres contained significantly more cells expressing OKT4 or Leu 3A antigens and cells bearing Fc mu receptors or containing Gall bodies. The Tsens fraction was enriched for cells with Fc gamma receptors but not for cells expressing OKT8 or LEU 2A. The results suggest that the Tres fraction is enriched for cells with putative helper markers and that the Tsens fraction is enriched for cells with some suppressor markers but also contains a large number of cells of monocytic lineage. However, the two fractions are not homogeneous with respect to Fc receptor status, presence of Gall bodies or antigens defined by OKT or Leu antisera, hence the use of theophylline sensitivity as a means of estimating the sizes of the helper and suppressor populations does not seem advisable.

A comparison of three reverse haemolytic plaque assays.

One fluid phase and two solid phase reverse haemolytic plaque (RHP) assays were used to quantitate plaque forming cells (PFC) in pokeweed mitogen (PWM) stimulated and unstimulated cultures of mononuclear cells (MNC) from 18 normal donors. There was a close correlation between the results of the three assays and between each one and the number of cells containing cytoplasmic Ig (cIg). All three correctly identified donors with a low PWM response. The fluid phase assay was the most sensitive with PFC values in PWM stimulated cultures two to four times higher than with the solid phase assays.

The effect of phenytoin in vitro on normal human mononuclear cells and on human lymphoblastoid B cell lines of different Ig isotype specificities.

The anticonvulsant drug phenytoin, in less than cytotoxic concentrations, caused significant reductions in Ig secretion by unstimulated or EBV-stimulated normal MNC, as measured by PFC or secretion of Ig into the culture medium. Isotype-specific LBL varied in their sensitivity, the secretion of IgA (1 line) and IgG (3 lines) being reduced by phenytoin near therapeutic concentrations, whereas that of IgM (1 line) was resistant. Six-day exposure of MNC to phenytoin caused no selective depletion of or enrichment for B cells, monocytes or T cell subsets. The results suggest that the reduction in serum Ig levels reported in phenytoin-treated epileptic patients is, at least in part, due to a direct effect of the drug on the B lymphocyte. However, among EBV-activated normal MNC, those secreting IgA were no more sensitive to the drug than those secreting IgG or IgM, and other factors may, therefore, operate to cause the preferential reduction in serum IgA in phenytoin-treated patients.

T and B lymphocytes in pleural effusions.

To determine the diagnostic significance of the determination of T and B lymphocytes in pleural fluid, we studied these cells in peripheral blood and in pleural fluid by means of surface markers. Our study comprised 30 patients suffering from pulmonary tuberculosis, pulmonary malignancy, connective tissue disease, nonspecific pleurisy or congestive cardiac failure. In pulmonary tuberculosis, both the percentage and absolute numbers of T lymphocytes in pleural fluid were significantly higher than in peripheral blood. In patients with pulmonary tuberculosis, pulmonary malignancy or nonspecific pleuritis, the percentages and absolute numbers of B lymphocytes were significantly lower in pleural fluid than in peripheral blood. Considered together with other clinical and laboratory indices, these determinations may aid in the differential diagnosis of pleurisy of various etiology.

Hypothyroidism and anti-endothelial cell antibodies.

Because of our previous demonstration of anti-endothelial cell antibodies (AECA) in patients with insulin-dependent diabetes mellitus and their association, in this condition, with thyroid disease, we sought these antibodies in patients with suspected thyroid dysfunction using an enzyme immunoassay with human umbilical vein endothelial cells as the substrate. AECA were found in 5/120 (4.2%) patients with normal and 15/97 (15.4%) with abnormal thyroid function. The increased prevalence in the latter group was due to a highly significant association between the presence of AECA and raised levels of TSH. We conclude that a highly significant correlation exists between the levels of AECA and TSH, but not between those of AECA and fT4. Patients with hypothyroidism as defined by high levels of TSH have AECA significantly more often than patients with low or normal TSH (22.2% versus 2.8% and 5.8%).

A comparison of two methods for the immunoassay of intrinsic factor.

The intrinsic factor content of 263 samples of gastric juice was determined by immunoassay using charcoal absorption and by immunoelectrophoresis on acrylamide gel. There was good correlation between the results of the two techniques and, with a few exceptions, both made it possible to predict which patients would have malabsorption of radioactive vitamin B(12). Of the two methods, immunoassay using charcoal absorption generally gave the higher readings. Further study showed that this could not be attributed to the recognized difference in the principles of the two methods but that it was more likely to be due to the dissimilarity of the experimental conditions.

Childhood malaria parasitaemia and human immunodeficiency virus infection in Malawi.

PIP: Malaria and human immunodeficiency virus (HIV) infection are major health problems in many areas in Sub-Saharan Africa. An interaction between malaria and HIV infection has been postulated, since both produce similar cellular immune responses, with a lowering of the CD4/CD8 lymphocyte ratio. The frequency of malaria parasitemia was examined in children born to HIV-seropositive and seronegative mothers attending regular postnatal visits. A prospective study on mother-to-infant transmission of HIV had been underway since 1989 in Queen Elizabeth Central Hospital, Blantyre, a major hospital in urban Malawi. Standard HIV serology was performed on pregnant women, after obtaining consent. To reduce the effect of selection bias and seasonality, HIV seropositive (case) and seronegative (control) mothers and their infants were enrolled at delivery. Children included in the study were 503 born to 494 HIV-seropositive mothers and 540 born to 536 HIV-seronegative mothers. At each 3-monthly postpartum visit a Giemsa-stained thick blood film from the child was examined for malaria parasites. Children born to HIV-seropositive mothers were tested for HIV antibodies at 12 and 18 months of age. Of the 353 children born to HIV-seropositive mothers, 82 children (23.2%) were found to be HIV seropositive by enzyme-linked immunosorbent assay and Western blotting at 12 and 18 months. No statistically significant difference was found in frequency of malaria parasitemia by maternal or infant HIV serostatus after controlling for child's age. There was, however, a significant trend of increase in high parasitemia with age, irrespective of the HIV serostatus of the mother or the child. The frequency of parasitemia was higher in the wet season than in the dry season. This study suggests that maternal or infant HIV infection does not alter susceptibility to, or the clinical course of, malaria in infants.^ieng

Sustained growth but non-sustainable urbanisation in Penang, Malaysia.

PIP: Penang, Malaysia, has been a city characterized by urban growth and rapid industrialization for the past 25 years. Foreign capital, especially from the transnational electronics industry, has spurred the process of urban growth in the city. While the state government is clearly trying to copy and adapt some form of a Singapore model of development and growth in Penang, the quantitative and qualitative demands for labor exceed the available supply from the country's northern states. Local and national labor policies are decided without the involvement of trade unions, which lack the strength to substantially improve wages or influence the institutions of the labor market. Therefore, an energized labor market attempts to balance the upgrading of skills and the control of wages. Focus upon sustainable urbanization will renew the debate on urban, export-oriented industrialization in southeast Asia.^ieng

Lymphocyte subpopulations in rheumatoid synovial tissue.

Synovial tissue obtained at synovectomy of the knee joint in 21 patients with rheumatoid arthritis contained a significantly lower proportion of T lymphocytes as measured by spontaneous rosette formation with nonsensitized sheep red blood cells than did synovial fluid or blood from the same patients. There was on concomitant increase in synovial tissue lymphocytes with B-cell markers such as surface immunoglobulin or Fc fragment receptors. Removal of lymphocyte receptors with trypsin followed by culture to allow new receptors to form, led to an increase in rosette forming cells, suggesting that part of the synovial cells without B- or T-cell markers may be T lymphocytes with blocked receptors.

Suppression of in vivo antibody responses by suppressor factors induced by human myeloma proteins.

Suppressor factors induced in vitro, using purified human IgG and IgA myeloma proteins, were shown to efficiently suppress murine antibody production in vivo. The suppression was not isotype specific, viz. IgG and IgA suppressor factors suppressed the production of IgM and IgG antibody. Neither the suppressor factors (SF) nor the inducing proteins suppressed the proliferative responses to concanavalin A and purified protein derivative (PPD). The results are compared to the in vitro findings and discussed in the context of isotype regulation, hypogammaglobulinemia and immunotherapy.

Australia antigen, autoantibodies and cell-mediated immune responses in patients with Down's syndrome.

The prevalence of Au antigen, autoantibodies and impaired cell-mediated immune responses was studied in 66 patients with Down's sydrome and 66 other mentally retarded patients in a South Australian institution. The antigen was detected in three of the former and none of the latter. This unexpectedly low carrier rate in patients with Down's syndrome was thought to be due either to good hygiene and state of nutrition in the institution or to the high age of which the patients had been admitted to hospital (eight to nine years). Because of the incompleteness of the association between impairment of cell-mediated immunity and antigen carriage, it was thought unlikely that the former was the sole reason for the latter.

Characteristics of suppressor factors generated from human mononuclear cells using concanavalin A and C-reactive protein.

Lymphocytes from normal human donors were cultured in Marbrook flasks in the presence of C-reactive protein (CRP), concanavalin A (Con A) or serum amyloid A protein low molecular weight component (SAAL) and the culture supernatants were tested for their ability to suppress the pokeweed mitogen (PWM) driven response of normal human lymphocytes. The supernatants from CRP and Con A stimulated lymphocytes, when added to cultures at initiation at a final concentration of 5%, suppressed the plaque forming cell (PFC) response in the three major immunoglobulin (Ig) classes. The suppressive effect could be removed by absorption of the culture supernatants with lentil lectin and with antisera to antigen specific helper and suppressor factors and could be recovered in the eluate. The results indicate that CRP stimulated cells exert their suppressive effect through a soluble mediator(s) which is similar to Con A generated suppressor factor(s) in respect to its time of action, its effect on the Ig classes M, G and A, its lack of cytoxicity and some structural aspects.

Immunological abnormalities in coeliac disease and their response to dietary restriction. I. Serum immunoglobulins, antibodies and complement.

Twenty-three patients with coeliac disease were studied whilst on a normal diet and again after a mean period of 15 months on a gluten-free diet. Serum levels of IgG, IgA and IgM, total haemolytic complement, C3, serum autoantibodies and precipitins to dietary proteins were compared to those in age and sex matched control subjects. There was considerable individual variation, but as a group, patients on a normal diet had significantly raised IgA and low IgM and an increased prevalence of antibody to reticulin, smooth muscle and dietary protein. These abnormalities disappeared during the period of dietary restriction suggesting that they are disease epiphenomena rather than primary pathogenetic factors.

Hypophosphatemic rickets, hyperparathyroidism, and hyperthyroidism with hypercalcemia.

We describe a case of hypophosphatemic rickets in which hyperparathyroidism and hypercalcemia developed and were possibly secondary to co-existent hyperthyroidism. During the period of hypercalcemia with high immunoreactive parathyroid hormone levels the serum inorganic phosphorus level became, and remained, normal. This supports the concept that renal tubular phosphate absorption may be sensitive to calcium.

Subclasses of IgG anticardiolipin antibodies in patients with systemic lupus erythematosus.

Antibodies directed to a co-factor associated with negatively charged phospholipids, such as cardiolipin, occur in patients with systemic lupus erythematosus (SLE), and possibly more often in those with venous or arterial thrombosis, thrombocytopenia or recurrent fetal loss. They are also found in patients without any of these manifestations and their biological effect, if any, might thus be related to their IgG subclass. To investigate this possibility, we determined anticardiolipin antibodies (ACA) by enzyme immunoassay (EIA) using monoclonal antibodies (MoAb) against human IgG subclasses. A net absorbance of x +3 SD of the value of 30 blood donors was taken as the cut-off point. The specificity of the assay was verified through inhibition experiments using cardiolipin micelles. Thirty-three patients with SLE were studied, all of whom had been shown to have ACA by a point dilution screening assay. IgG1 ACA were found in 85% of the patients, and ACA of the IgG2, IgG3 and IgG4 subclasses in 42%, 39% and 15%. There was a significant correlation between the presence of IgG3 ACA and of anti-DNA antibodies but none between subclass distribution and major clinical manifestations of SLE.

Effects of a human urinary mitogen on subpopulations of peripheral blood mononuclear leukocytes.

We have earlier isolated, to apparent homogeneity, a 27-28 kD human basic protein (UM) from the urine of a patient with myelomonocytic leukaemia. UM is a mitogen for resting human peripheral blood mononuclear leukocytes (PBML). We have now further defined the effect of UM on human PBML and their subpopulations in 6-day cultures. Cell proliferation was measured by 3H-thymidine uptake and Ig production by the plaque forming cell (PFC) response. Whole PBML responded to UM with proliferation and an increase in PFC. The PFC response was at best equal to and frequently synergistic with that produced by pokeweed mitogen and occurred in the three major Ig classes. To test the effect of UM on subpopulations of PBML, adherent cells (AC) were isolated by plastic adherence and T and B enriched populations by rosetting with sheep red blood cells. The proliferative response of T cells needed the presence of AC whilst the effect on Ig production by B cells required both T cell help and the presence of AC. Human thymocytes also responded to UM by proliferation. The results show that, in addition to being a T cell mitogen, UM is also a T cell dependent polyclonal B cell activator.