Immunologic dysfunction: simultaneous study of Alzheimer's and older Down's patients

Peripheral blood lymphocytes from Alzheimer's disease patients, older patients (aged 25-59 years) with Down's syndrome and closely age-matched healthy controls were tested in vitro for DNA synthesis in response to stimulation by phytohemagglutinin, pokeweed mitogen and OKT3 monoclonal antibody to T3 antigen. All were significantly decreased in Down's and Alzheimer's patients relative to healthy controls. The autologous mixed lymphocyte reaction (AMLR), unstimulated or stimulated with anti-T3. in the 2 patient groups did not differ significantly from the healthy controls. We also quantified the proportions of the T cells staining positive for surface membrane orosomucoid, and found their levels to be either higher or lower than normal in Down's patients, but not in Alzheimer's patients. These results demonstrate the existence of defective cellular immune functions in both elderly Down's patients and Alzheimer's patients.     

Increased activity of oligo-2'',5''-adenylate synthetase in Down''s syndrome and epilepsy.

The level of oligo-2',5'-adenylate synthetase activity is a good marker for the response of cells to interferon. This enzyme can polymerize ATP to form oligonucleotides in the presence of double-stranded RNA, i.e. polyinosinate-cytidylate in vitro. The activity of this enzyme in peripheral blood mononuclear leucocytes was significantly increased in Down's syndrome (P less than 0.01) and epilepsy (P less than 0.01) compared with that in healthy controls, but the increase of activity was not significant in multi-infarct dementia (MID) (P greater than 0.05). Although the patients with Down's syndrome showed higher levels of this enzyme activity than the controls, interferon activity was never detected in the circulation. In addition, the serum of patients with Down's syndrome lacked the capacity to induce this enzyme in NC-37 and FL cells, and furthermore it was shown that the inhibitor of interferon activity was not found in the serum of patients. This discrepancy in Down's syndrome may be the result of the hypersensitivity of cells to interferon. On the contrary, interferon activity (32 IU/ml) was detectable in the circulation of one patient with epilepsy, and the serum of this patient had the capacity to induce this enzyme in NC-37 and FL cells.     

Humoral immune function in severe, active rheumatoid arthritis

Peripheral blood mononuclear cells (PBMC) from 30 patients with definite or classic active rheumatoid arthritis who were on no remittive drugs were studied for spontaneous and pokeweed mitogen (PWM)-stimulated immunoglobulin plaque-forming cell frequency (IgPFC), spontaneous IgM-rheumatoid factor (IgM-RF) secretion, and in vitro proliferative responses to soluble recall antigens. Rheumatoid spontaneous total (IgG + IgM + IgA) IgPFCs were higher than those of normal controls when assayed after 7 days in culture. Spontaneous and PWM-stimulated IgM-PFCs, in contrast, were significantly less than normal regardless of when assayed. Spontaneous synthesis of IgM-RF was observed in 56% of the RA patients, but absolute amounts produced were widely heterogeneous. Spontaneous IgM-RF production by RA PBMC was associated with low or absent spontaneous IgM-PFC production. Moreover, a strong association was found between the median amount of IgM-RF secreted and depressed proliferative responses to soluble recall antigens. Our results define several abnormalities of immunoglobulin production in a clinically homogeneous and highly active rheumatoid population and delineate methodologic variations that can complicate the interpretation of similar data in the literature. In addition, our findings suggest that subgroups of rheumatoid patients that show distinct cellular and humoral immune abnormalities can be identified.     

Immunological studies in sickle cell disease: comparison of homozygote mild and severe variants

Cellular and humoral immune functions in patients suffering from severe and mild forms of homozygous sickle cell disease (SCD) were compared with those of healthy control subjects. Random neutrophil migration, chemotactic activity, and lymphocyte transformation index were all defective in individuals with severe variants of SCD when compared with individuals with mild disease or healthy controls. In contrast, serum opsonization activity was significantly reduced in both severe and mild variants of SCD. There were no statistical differences between serum immunoglobulin (IgA, IgG, and IgM) or complement C3 levels in any of the three groups. These results demonstrate that even though individuals with the mild variant of SCD possess two S genes, their immune functions are generally normal and in parallel with their clinical and hematological status. The one area of impaired immune function is their defective serum opsonization activity and this may explain their sensitivity to certain infections.     

Transient hypogammaglobulinemia, elevated immunoglobulin E levels, and food allergy.

Four infants presented with the combination of food allergy, transient hypogammaglobulinemia (THI), and elevated serum IgE levels. Food allergy was documented by history, positive skin tests for immediate hypersensitivity, radioallergosorbent test, histamine release studies, and lymphocyte transformation in response to food allergens. THI was probably secondary to decreased production since there was no evidence of protein loss from the gastrointestinal tract. Immunologic studies revealed normal B cell number and function in vitro. T cell number and proliferative response to mitogens and antigens were normal but T cells were deficient in their ability to generate helper factors necessary for B cell maturation into immunoglobulin secretory cells. The THI and the deficient production of T cell--helper factor resolved after the age of 20 to 24 mo. A defect in immunoregulation may be responsible for the immunologic abnormalities observed in these patients and their propensity to develop IgE antibodies to food allergens.     

Decreased 5'-nucleotidase activity in suppressor (OKT8) T lymphocytes from homosexuals with AIDS-related complex: nonassociation with enhanced deoxynucleoside toxicity

The purine metabolic enzymes adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), and 5'nucleotidase (5NT) have been shown to be important for normal lymphocyte maturation. Abnormalities of these enzymes have been associated with hereditary as well as acquired immunodeficiency states. Enzyme activity was measured in helper (OKT4) and suppressor (OKT8) lymphocyte subsets from 10 homosexuals with AIDS-related complex (ARC) and in 10 healthy controls. There were no significant differences in either mean ADA activity or mean PNP activity between ARC OKT4 cells and control OKT4 cells and between ARC OKT8 cells and control OKT8 cells. By contrast, mean 5NT activity was slightly decreased in OKT4 cells from ARC patients compared with that of controls and more significantly diminished in ARC OKT8 cells compared with that of controls. Both deoxyadenosine and deoxyguanosine, when incubated separately with OKT4 and OKT8 cells in the presence of EHNA, an ADA inhibitor, did not significantly inhibit lymphocyte blastogenesis to a greater extent in ARC patients than in controls. Hence, the decreases in 5NT activity most likely reflect lymphocyte immaturity and are not associated with biochemical abnormalities leading to increased deoxynucleoside toxicity.     

The effects of anti-estrogen therapy on lymphocyte functions in breast cancer patients.

The effects of anti-estrogen therapy (tamoxifen or toremifene) on in vitro lymphocyte functions were investigated in breast cancer patients. We found that the amount of DNA synthesis, with or without PWM stimulation, was decreased in all cancer patient groups compared to normal controls. The number of Ig-secreting cells was enhanced in unstimulated peripheral blood lymphocyte cultures but decreased in PWM-stimulated cultures. This occurred in all cancer patient groups investigated, with or without anti-estrogen therapy, as compared to healthy controls. On the other hand, subsequent samples with two-month intervals showed that anti-estrogens can increase PFC responses and inhibit DNA synthesis of peripheral blood lymphocytes in more than half of the patients. Interestingly, the enhancing dexamethasone effect, which usually causes an increase in the number of Ig-secreting cells in PWM-stimulated cultures, was also seen more often in anti-estrogen-treated patients. These results suggest that anti-estrogens may have immunoregulatory effects in vivo.     

Serum dopamine-β-hydroxylase levels in Down's syndrome

Serum dopamine-β-hydroxylase (DBH) and serum immunoreactive (IR) DBH levels were measured in patients with Down's syndrome. Serum DBH activity was markedly reduced in Down's syndrome patients as compared with age matched, normal controls or non-mongoloid, disturbed children. Serum IR-DBH levels were also markedly reduced in Down's syndrome. The possible factors responsible for the observed reduction in serum DBH levels (active and inactive enzyme levels) in Down's syndrome were investigated.     

Cell-mediated immunodeficiency in Down''s syndrome: normal IL-2 production but inverted ratio of T cell subsets.

To get more information on the mechanism of cell-mediated immunodeficiency associated with Down's syndrome, 18 patients were studied for PHA-induced lymphocyte transformation and interleukin-2 (IL-2) production. A normal amount of IL-2 was produced although half of the patients showed decreased blast transformation. T cell subpopulations were studied in some patients with decreased and with normal blast transformation. All studied patients with decreased blast transformation had inverted helper/suppressor T cell ratio.     

White cell function in Down''s syndrome

Neutrophil function was studied in 25 patients with Down's syndrome at a mental subnormality hospital and compared with 26 normal controls. In vitro killing of Candida albicans was significantly lower in the Down's group, but there was no difference in the percentage of cells actively involved in phagocytosis or in the phagocytic index. The spontaneous nitroblue tetrazolium reduction was increased in 10 patients, but no abnormality of peroxidase activity or leucocyte alkaline phosphatase activity was found.     

Decreased suppressor T cell activity in patients with hepatic cirrhosis (HC).

Hypergammaglobulinaemia (HGG) is frequently found in patients with hepatic cirrhosis (HC). Using an assay system of in vitro PWM-stimulated immunoglobulin (Ig) production, the amounts of IgG, IgA, and IgM produced by peripheral blood lymphocytes (PBL) from 15 HBs Ag-negative patients with HC and from 16 age-matched healthy subjects were quantitated by radioimmunoassay. We found that PBL from patients with HC produced significantly greater amounts of IgG (P less than 0.05) but not IgA or IgM than did those from control subjects. This increased IgG production by PBL from patients with HC was attributed to enhanced T helper activity and not to enhanced B cell function. We also searched for defects in naturally occurring suppressor T cell activity which is sensitive to irradiation. Irradiation-induced enhancement for IgG production was significantly lower in patients with HC compared with age-matched control subjects (P less than 0.01). Similarly, we examined the effect of Con A-induced suppressor T cells on the in vitro PWM-stimulated IgG production by allogeneic PBL and observed the decrease of Con A-induced suppressor T cell activity in patients with HC (P = 0.01). We conclude, therefore, that the increased serum levels of Ig, particularly IgG in patients with HC may result from in part on the basis of depressed ability of naturally occurring suppressor T cells or Con A-induced suppressor T cells to suppress Ig production.     

Decreased blood natural killer cell activity and immunoglobulin synthesis in vitro in aplastic anemia

Natural killer (NK) cell numbers and T lymphocyte subpopulations in peripheral blood were evaluated in six patients with aplastic anemia (AA). The immunophenotyping results were correlated to in vitro tests of NK cell cytotoxicity against K562 cells and of immunoglobulin (Ig) production after pokeweed mitogen (PWM) stimulation. A significant decrease was found both in the percentage of Leu 11 positive cells and in NK cell activity as compared to age- and sex-matched healthy controls. The decrease in NK cell activity could not be entirely compensated by an increase in effector/target cell ratios, thus suggesting not only a quantitative but also a functional defect in NK cells of the AA patients. Three of four AA patients tested showed no major increase of Ig production after PWM stimulation. All these three patients also had fewer "functional T helper" cells (Leu3+/Leu8-) and increased numbers of T suppressor/cytotoxic cells (Leu2+) when compared to controls. No significant differences in numbers of B lymphocytes (B1+) could be found. Our findings suggest a possible linkage between quantitative and qualitative abnormalities in lymphocyte subsets in aplastic anemia. However, no evidence was found to support the hypothesis of increased NK cell activation behind the hemopoietic depression in this disease.     

T- and B-Cell Functions in IgA-Deficient Patients

In vitro lymphocyte function of 60 IgA-deficient patients (IgAdp) were studied. In the mitogen-induced lymphocyte activation test, peripheral blood mononuclear cells (PBMC) of IgAdp showed a weaker response to pokeweed mitogen (PWM) than those of controls (P less than 0.05), and the responses to phytohaemagglutinin (PHA) and concanavalin A (Con A) were normal. The amounts of IgA, IgG, and IgM secreted by PBMC from controls and IgAdp were measured in vitro by enzyme immunoassay. B cells were activated by PWM with or without hydrocortisone (HC) to inhibit HC-sensitive suppressor cells. Lymphocytes of IgA-deficient patients synthesized only minute amounts of IgA in vitro and the amounts of IgA synthesized correlated well with the serum IgA levels. Both IgG and IgM secretion by PWM-stimulated PBMC of IgAdp were also subnormal. The lymphocyte subset analysis in the peripheral blood revealed normal numbers and ratios of T cells, but IgAdp had reduced percentages of surface IgA-bearing cells. Co-culture experiments with isolated B cells, CD4- and CD8+ cells from IgAdp. and controls showed low B-cell capacity for IgA production as the most constant finding. Defects in T-cell functions or changes in the proportions of surface antigen-carrying lymphocytes (other than IgA-) were infrequent and were not associated with any particular group of patients or type of IgAd (primary, acquired, or transient).     

Alphafetoprotein in midtrimester Down''s syndrome fetal serum.

Serum alphafetoprotein was estimated in fetuses with and without Down's syndrome or with other chromosome abnormalities from the 17th to the 28th week of pregnancy. In normal fetuses, the AFP level declines steadily during this period. Before 20 weeks, there was no difference in the serum AFP levels of the three groups of fetuses. After 20 weeks, the serum AFP level in cases of Down's syndrome declined more rapidly than normal. This was not observed in fetuses with other chromosome abnormalities. This suggests that low maternal serum alphafetoprotein levels used for prenatal screening for Down's syndrome in the early second trimester cannot be explained by low levels in the Down's fetuses themselves.     

T-cell dysfunctions in IgA nephropathy: specific abnormalities in the regulation of IgA synthesis

This work was undertaken to determine the cellular abnormalities that could explain the high levels of serum IgA frequently found in patients with IgA nephropathy. Seventeen control subjects and twenty-seven patients who had received no therapy were studied. After in vitro pokeweed mitogen (PWM) stimulation, significantly higher amounts of IgA were produced by peripheral blood mononuclear cells (PBM) of patients when compared with those of the control group (560 +/- 97 vs 231 +/- 57 ng/ml, P less than 0.0025). No differences were observed in the synthesis of IgG and IgM. Twenty out of twenty-seven patients presented an increase in the percentages of OKT4+ cells (mean + 2 SD), in relation to the control group, with normal or elevated percentages of OKT8+ cells. The OKT4+/OKT8+ cell ratio was elevated in 12 out of 27 patients. All patients presented some abnormality in the generation of IgA-specific suppressor cells at variable doses of concanavalin A (Con A) on in vitro PWM-stimulated culture of PBM. In both assays low doses of Con A (2.5 micrograms/ml) induced a certain suppression of IgA synthesis in patients that was not observed in the majority of the control group. At these doses some patients also showed an enhancement in the synthesis of IgG and IgM. On the contrary, higher doses of Con A (50 micrograms/ml) produced significantly less IgA suppression than the controls. Normal IgA-suppression values were found at 10 micrograms/ml of Con A. T cells obtained from patients were significantly more efficient than T cells from controls in providing IgA-helper activity for normal allogeneic enriched B cells (P less than 0.025) in PWM-stimulated cocultures. These results show that patients with IgA nephropathy present, after mitogen stimulation in vitro, a specifically increased production of IgA as well as an augmentation in the activity of IgA-helper T cell and a deregulation on IgA-suppressor T-cell function. According to these data, it is suggested that the alteration observed in helper T cells might precede that of suppressor T cells. These immunoregulatory abnormalities might contribute to the pathogenesis of the disease.     

Sequential studies of lymphocyte responsiveness and antibody formation in acute bacterial meningitis.

Lymphocyte transformation responses in vitro were studied in eight patients with acute bacterial meningitis (in five due to Neisseria meningitidis). Sequential studies were done from 24--48 hr after the first symptoms of infection to complete recovery. In all cases lymphocyte transformation was depressed during the acute phases of illness. The responses to microbial antigens were more affected than the responses to mitogens. The course of the lymphocyte responses to the causative micro-organism showed no difference from the responses to other microbial species. A moderate shift towards increased sensitivity of the lymphocytes to lower doses of the causative micro-organism was observed during the course of illness in three cases. In N. meningitidis infection, a rapid rise was seen in the serum titres of complement-fixing antibodies and in the number of precipitating antibodies, whereas the rise in immunoglobulin concentrations was more prolonged. Characteristic patterns of elevation and return towards normal were found in the serum concentrations of the acute-phase reactants alpha1-antitrypsin, haptoglobin, and orosomucoid. It is concluded that the lymphocyte transformation responses in vitro during severe bacterial infection are largely governed by non-specific factors, and that studies of lymphocyte responses to micro-organisms should always include other microbial species as controls.     

T and B Lymphocytes in Patients with Nickel Sensitivity

Peripheral blood mononuclear cells from altogether 45 nickel-sensitive patients and 37 controls were assayed for various T and B cell variables. All the patients, but none of the controls, fulfilled our in vitro criteria for a positive response to nickel sulphate (NiSO4). We report normal T and B lymphocyte counts, normal spontaneous plaque-forming cell (PFC) numbers, normal serum immunoglobulin levels, and no demonstrable specific cytotoxic T lymphocyte activity associated with nickel sensitivity. We could detect only a slight increase in the number of PFC and in the number of cytoplasmic immunoglobulin positive (cIg+) cells following stimulation of the patients' cells with NiSO4 for 6 days in culture. Apart from a transient increase in the [3H]thymidine uptake by patients' cells stimulated with NiSO4 in vitro, and a transient drop in the OKT4/OKT8 ratio, there were no major differences in the values of the above variables before and after in vivo challenge of 3 patients with NiSO4. Blood from only 2 of the latter 3 patients was tested in the DNA synthesis test. We conclude that apart from the DNA synthesis test, none of these tests is of any use as an aid to diagnosis in patients with nickel sensitivity. A careful attitude towards patch testing should be maintained.     

SERUM IMMUNOGLOBULINS AND LYMPHOCYTE SUBPOPULATIONS DERANGEMENT IN TURNER'S SYNDROME

Abnormalities of the proportions of peripheral blood lymphocyte subpopulations and of immunoglobulin serum levels were found in twenty patients affected by Turner's syndrome. A slight but significantly decreased percentage of circulating T and B cells, an increased percentage of null cells and a decreased in vitro, responsiveness of lymphocytes to phytohaemagglutinin, concanavalin A and pokeweed mitogen were found in Turner's syndrome patients. IgG serum level was found significantly decreased in comparison with age-matched fifty-seven normal males and fifty-seven normal females and IgM serum level was intermediate between female and male values; Turner's syndrome patients with monosomy had an IgM serum concentration very close to male values. The derangement of T and B lymphocyte subpopulations, probably related to the aneuploidy, does not seem to be a severe one but it could account for the immunoglobulin abnormalities and for the association of Turner's syndrome with immunological disorders such as autoimmune diseases. The role of X chromosome on IgM serum level is discussed.     

Theophylline-induced alterations in cellular immunity in asthmatic patients

Twenty patients with bronchial asthma, on long-term oral therapy with theophylline, demonstrated an increased number of suppressor T-cells and impaired graft vs host reaction. Ten asthmatics on other therapy, not including theophylline, as well as ten normal healthy controls, failed to show similar findings. Elimination of suppressor T-cells corrected the above immunological abnormalities in the theophylline-treated patients, while addition of serum from theophylline-treated asthmatic patients to lymphocytes from normal healthy controls, affected the graft vs host reaction of these lymphocytes. We conclude that theophylline induces quantitative as well as qualitative immunological alterations by increasing the number and activity of suppressor T-cells, which most probably secrete a serum factor, responsible for some of the abnormalities observed.     

A comprehensive study of immunological abnormalities in Korean hemophiliacs

To determine laboratory evidence suggesting immunological abnormalities in persons with hemophilia, we evaluated the immunological status of 75 Korean hemophiliacs, seronegative for human immunodeficiency virus (HIV) antibodies, who have been treated only with Korean factor VIII concentrates. From this study, it was shown that Korean hemophiliacs had decreased CD4 levels, increased CD8 levels, and decreased CD4:CD8 ratios. Diminished lymphocyte response to the mitogens, phytohemagglutinin and concanavalin A, and decreased natural killer cell activity were observed in the hemophiliacs. In addition, production of interleukin-II in the hemophiliacs was lower than in the healthy controls. The percentage of B lymphocytes was significantly reduced but the serum levels of immunoglobulin (Ig) G were elevated. However, the serum Ig A and Ig M levels were normal. This study demonstrated a high frequency of immunological abnormalities in HIV antibody negative Korean hemophiliacs treated only with domestic factor VIII concentrates.