Increased circulating Ia-antigen-bearing T cells in type I diabetes mellitus

The Effect of Transforming Growth Factor β1, and Tumor Necrosis Factor α on the Cytotoxic-Cytostatic Action of Interleukin-1 (α and β Isoforms) on the Pancreatic B Cell Line Rin-5ah

The rat pancreatic β cell line RIN-5AH was treated with the cytokines IL-1 (α and β), TNFα and TGF-β1, in order to examine at the clonal level the reported mostly cytotoxic effects of IL-1, on isolated islets of Langerhans and islet cell preparations. In contrast to what has been previously reported for whole islets and islet cell preparations we find that IL-1 (α or β) is not cytotoxic to the RIN-5AH cells in logarithmic growth phase to any extent, even at very high cytokine concentrations (125 nM). Furthermore, TNFα does not in any way potentiate IL-1 cytotoxicity. Transforming growth factor-β1 (TGF-β1) at concentrations of 80 pM to 2 nM, has a potentiating effect on IL-1 cytotoxicity (conc. 5 nM) for this clonal cell line. The effect is proportional to the level of TGF-β1 present and is exerted regardless of the IL-1 isoform used. The effects of the various cytokines, alone or in combination, were only observed at high (25 mM) glucose concentrations, and no such effects were observed at the physiological (5 mM) glucose concentration. Furthermore the combination of TGF-β1 and IL-1 inhibits the release of insulin by these cells, whereas either cytokine alone has no effect.

We conclude that the RIN-5AH cells in showing little cytotoxic/cytostatic response to IL-1 are responding more as isolated β cells than as cells within islets. The potentiation of the action of IL-1 by TGF-β1 on these cells is a matter of further investigation.

Cyclosporin and methotrexate therapy induces remission in type 1 diabetes mellitus

Cyclosporin and methotrexate administration induces remission of type 1 diabetes mellitus. Administration of high-dose cyclosporin (cyclo) has been demonstrated to induce remission of type 1 diabetes mellitus (T1D). Its usefulness was limited by its toxicity. Since methotrexate (mtx) and cyclo synergistically inhibit autoimmune processes, we postulated that low doses of cyclo and mtx could safely induce remission of T1D. In a pilot study, insulin dose requirements and glycemic control were compared in 10 new onset T1D control children with seven children who were administered cyclo at 7.5 mg/kg/day for 6 weeks and then 4 mg/kg/day in addition to mtx 5 mg/kg/wk for 1 year. After 6 weeks, cyclo doses were adjusted to maintain blood cyclo levels 110-220 ng/ml. All children were treated with two daily injections of insulin. Clinical and biochemical toxicity of drug therapy was assessed. There were only very minor adverse effects and no drug induced biochemical test abnormalities. Mean HbA1c levels were similar in the experimental and control groups at baseline and at 3, 6, and 9 months but was lower in the cyclo + mtx group at 12 months. Daily insulin requirements of the groups were similar at baseline but lower in the cyclo + mtx group at 3, 6, 9, and 12 months. Although no control subjects became non-insulin requiring, four of seven cyclo + mtx-treated subjects were entirely off insulin therapy for 2.5, 4.5, 8, and 12 months. Low-dose cyclo and mtx treatment of subjects with new onset T1D can safely induce remission of disease and decrease the amount of required insulin.

Characterization of anti-islet cytotoxic human T-cell clones from patients with type 1 diabetes mellitus

To identify important anti-islet T-cells and their target antigen(s), we have isolated and characterized seventeen human T-cell clones which are reactive to an extract of rat insulinoma (RIN) cells from three children with new onset type 1 diabetes mellitus (T1D). Of these 17 clones, 15 were found tissue specific. Six of eight tested tissue specific clones did not recognize known islet antigens such as GAD, 52 kDa islet protein, insulin, ICA512, and heat shock protein 60 (hsp60), suggesting that these clones recognize an autoantigen not previously identified. All tested clones were phenotypically CD4 and functionally Th0 or Th0/Th1 cells. One RIN extract reactive clone (2E9) recognized hsp60 and was CD4 and TCR alpha/beta positive. This clone also proliferated in response to human and rat islets suggesting that the antigen is conserved between species. This clone and 75% of all the tested RIN reactive clones exhibited anti-islet cytotoxicity by lysing target cells coated with RIN extract. HLA DR determinants may play a role in this cytotoxic activity since preincubation with HLA DR antibody decreased the anti-islet cytoxicity of the two tested clones. In conclusion, we have isolated RIN reactive CD4+T-cell clones from diabetic subjects, six of which appears tissue specific and non-reactive to putative important islet antigens, and in turn may be recognizing yet undiscovered islet antigens. The high frequency anti-islet cytotoxic properties of the islet reactive clones provides evidence for a role of CD4+ cytotoxic T-lymphocytes in the diabetic process. Further, the isolation of hsp60 reactive clone with anti-islet cytotoxic properties suggests that cell mediated immunity against hsp60 may be important in the pathogenesis of diabetes.

Effect of insulin-dependent diabetes mellitus on response to extracorporeal photopheresis in patients with Sézary syndrome

BACKGROUND

Extracorporeal photopheresis (ECP) has become a primary therapy for selected forms of cutaneous T-cell lymphoma, especially Sézary syndrome. Variability in response of patients with Sézary syndrome to ECP has been reported.

OBJECTIVE

Our purpose was to determine whether underlying medical conditions influence the efficacy of ECP in patients with Sézary syndrome.

METHODS

We retrospectively reviewed the medical records of 55 patients with Sézary syndrome who received ECP between 1987 and 2000. Efficacy criteria included decrease in Sézary cell count, erythroderma, lymphadenopathy, organomegaly, and pruritus.

RESULTS

Thirty-four patients responded well and 10 patients responded partially to ECP; 11 patients had no response. Nine patients with no response to ECP had insulin-dependent diabetes mellitus (IDDM). IDDM was documented in only 2 patients with a good response and in no patients with a partial response to ECP.

CONCLUSION

Patients with Sézary syndrome and IDDM typically respond poorly to the standard ECP treatment regimen.

Cytokine expression in unstimulated PBMC of children with type 1 diabetes and subjects positive for diabetes-associated autoantibodies

The aim of this study was to evaluate possible changes in the circulating levels of interferon (IFN)-gamma, interleukin (IL)-4 and transforming growth factor (TGF)-beta in association with the autoimmune process leading to type 1 diabetes. Expression levels of mRNAs specific for each cytokine were determined in peripheral blood mononuclear cells (PBMC) by a multiplex reverse transcription-polymerase chain reaction (RT-PCR) followed by hybridization reactions with lanthanide-labelled probes and detection by time-resolved fluorometry. Newly diagnosed diabetic children had lower levels of IFN-gamma, IL-4 and TGF-beta 1 signals compared to their age- and sex-matched controls (P < 0.02, P < 0.005 and P < 0.005, respectively) and also the autoantibody-positive subjects had significantly lower levels of IL-4 and TGF-beta 1 in comparison with their matched controls (P = 0.0013 and P = 0.012). No significant differences were observed when comparing matched pairs of diabetic children and autoantibody-positive subjects. Our results suggest a systemic bias towards reduced production of T-helper cell type 2 cytokines (IL-4 and TGF-beta 1) during the autoimmune process, but there was also a reduced level of IFN-gamma expression in the periphery at the onset of clinical diabetes.

Treatment of autoimmune premature ovarian failure

There is no known immunosuppressive therapy for autoimmune premature ovarian failure that has been proven safe and effective by prospective randomized placebo-controlled study. Nevertheless, immunosuppression using corticosteroids has been used on an empirical basis for this condition. Here we present two cases of young women with premature ovarian failure who were treated with glucocorticoids in the hopes of restoring fertility. The first case illustrates the potential benefit of such therapy, and the second case illustrates a potential risk. The first patient with histologically proven autoimmune oophoritis was treated with alternate day glucocorticoid treatment. She had return of menstrual bleeding six times and ovulatory progesterone concentrations four times over a 16 week period. The second patient with presumed but unconfirmed autoimmune ovarian failure was referred to us after having been treated with a 9 month course of corticosteroids. During that treatment her menses did not resume. The corticosteroid treatment was complicated by iatrogenic Cushing syndrome and osteonecrosis of the knee. Identifying patients with autoimmune premature ovarian failure presents the opportunity to restore ovarian function by treating these patients with the proper immune modulation therapy. On the other hand, potent immune modulation therapy can have major complications. Corticosteroid therapy for autoimmune premature ovarian failure should be limited to use in placebo-controlled trials designed to evaluate the safety and efficacy of such treatment.

The destructive action of IL-1alpha and IL-1beta in IDDM is a multistage process: evidence and confirmation by apoptotic studies, induction of intermediates and electron microscopy

Using the rat beta-cell RIN-5AH insulinoma line as a means for studying insulin-dependent diabetes mellitus (IDDM), it is shown that interleukin-1 (IL-1) induces beta-cell damage initiated by early apoptotic signals. This action is demonstrated by DNA fragmentation, as assessed by specific BrdU labeling, surface expression of Fas and nitric oxide (NO) production. In addition, the interplay between NO and Fas is shown, while scanning electron microscopy (SEM) confirms apoptosis by revealing the degree and type of cellular damage which, in the case of IL-1alpha, can be reversed by an inhibitor to NO synthesis. Apoptosis is also reconfirmed by transmission electron microscopy (TEM) by observing condensed nuclear chromatin after IL-1 exposure. Thus, treatment of insulinoma cells with IL-1alpha and IL-1beta seems to initiate a number of signals, including PKC activation as published previously, that ultimately lead to beta-cell destruction. Each IL-1 isoform, however, definitely follows a different pathway of action.

Premature ovarian failure

In 1% of women, premature ovarian failure develops by 40 years of age, a condition causing amenorrhea, infertility, sex steroid deficiency, and elevated gonadotropins. Early loss of ovarian function has significant psychosocial sequelae and major health implications. These young women have a nearly two-fold age-specific increase in mortality rate. Among women with spontaneous premature ovarian failure who have a normal karyotype, half have ovarian follicles remaining in the ovary that function intermittently. Indeed, pregnancies have occurred after the diagnosis of premature ovarian failure. Thus, premature ovarian failure should not be considered as a premature menopause. Young women with this disorder have a 5% to 10% chance for spontaneous pregnancy. Attempts at ovulation induction using various regimens fail to induce ovulation rates greater than those seen in untreated patients; however, oocyte donation for women desiring fertility is an option. Young women with premature ovarian failure need a thorough assessment, sex steroid replacement, and long-term surveillance to monitor therapy. Estrogen-progestin replacement therapy should be instituted as soon as the diagnosis is made. Androgen replacement should also be considered for women with low libido, persistent fatigue, and poor well-being despite taking adequate estrogen replacement. Women with premature ovarian failure should be followed up for the presence of associated autoimmune endocrine disorders such as hypothyroidism, adrenal insufficiency, and diabetes mellitus.

Increased CD69 and human leukocyte antigen-DR expression on T lymphocytes in insulin-dependent diabetes mellitus of long standing

To better define prevailing activation of circulating T cell subsets in insulin-dependent diabetes mellitus (IDDM) of recent onset (DM; n = 31; median age +/- SD, 28 +/- 6.9 yr) and of long standing (DML; n = 27; age, 33 +/- 10.4 yr; median duration of disease, 105 months), CD4+ and CD8+ T cells were analyzed to determine their naive and memory subsets as well as their expression of human leukocyte antigen (HLA)-DR, interleukin-2 receptor alpha-chain (CD25), and CD69 by three-color flow cytometry. Twenty-six healthy subjects (HS; age, 32.0 +/- 8.2 yr) served as controls. No deviation was seen in either IDDM group compared to HS in CD25 expression on CD4+ or CD8+ cells or in their CD45RA+ or CD45RA- subsets. HLA-DR expression, however, was increased (P < 0.05) in total CD8+ cells and CD45RA+ cells, with CD45RA- CD8+ cells joining the prevailing pattern only in DML. Among CD4+ cells, increased expression of HLA-DR molecules was restricted to total and CD45RA- cells in DML. CD69 expression did not differ between IDDM and HS, but differed between DML (CD4+, CD8+, and CD45RA- CD4+) and DM only. In conclusion, our data demonstrate that HLA-DR expression in IDDM is restricted to memory cells (CD45RA-) among CD4+ cells in DML and is more markedly confined to naive (CD45RA+) than to memory CD8+ cells, whereas the early activation antigen CD69 is more readily expressed in DML than in DM. The observed activation of circulating T cells suggests an ongoing immune process in IDDM both at clinical manifestation and after long duration.

Characterization of a human T cell line reactive to a 52 kDa islet protein

A 52 kDa islet protein has recently been identified as the target of autoantibodies in the NOD mouse model of IDDM and humans with IDDM. However, the presence of T cell immunity against the 52 kDa islet protein in IDDM has not been reported. We report the establishment and characterization of a T cell line (19KW) that reacts to purified 52 kDa islet protein (purified p52) from a subject with IDDM. The purified p52 induced a proliferative response as measured by thymidine incorporation in the 19KW T cell line with a stimulating index of up to 48. The proliferative responses were greater with increasing doses of purified p52 (0.1, 0.5, 2.0, and 6.0 microg/well). No reactivity was found to a liver fraction purified in the same manner as 52 kDa protein, BSA, ovalbumin, extracts of rat muscle, fibroblast, adrenal, or pituitary tissue and to a rat exocrine cell tumor. Irradiated PBMC were required as antigen presenting cells (APC) for 19KW reactivity to the purified p52. The addition of anti-HLA DR or anti-HLA DQ antibodies significantly decreased the islet antigen-induced proliferative response. The addition of antibodies to HLA DP and class I MHC had no effect. Flow cytometric analysis revealed that the majority of T cells expressed CD4 and CD45RO molecules. T cell receptors Vbeta6 and Vbeta5.1 were found on 30 and 14% of the CD3+ (T cells) 19KW cells, respectively. In conclusion, a purified p52-reactive human T cell line predominantly consisting of TCR Vbeta6+ and Vbeta5.1+ cells has been established from a subject with IDDM. Reactivity to the purified p52 is antigen dose-dependent, tissue specific, requires irradiated PBMC as antigen presenting cells, and is HLA DR- and HLA DQ-restricted. T cell lines specifically reactive to p52 may be useful for investigating further the role of this antigen in the pathogenesis of IDDM.

Premature ovarian failure and ovarian autoimmunity

Premature ovarian failure (POF) is defined as a syndrome characterized by menopause before the age of 40 yr. The patients suffer from anovulation and hypoestrogenism. Approximately 1% of women will experience menopause before the age of 40 yr. POF is a heterogeneous disorder with a multicausal pathogenesis involving chromosomal, genetic, enzymatic, infectious, and iatrogenic causes. There remains, however, a group of POF patients without a known etiology, the so-called "idiopathic" form. An autoimmune etiology is hypothesized for the POF cases with a concomitant Addison's disease and/or oöphoritis. It is concluded in this review that POF in association with adrenal autoimmunity and/or Addison's disease (2-10% of the idiopathic POF patients) is indeed an autoimmune disease. The following evidence warrants this view: 1) The presence of autoantibodies to steroid-producing cells in these patients; 2) The characterization of shared autoantigens between adrenal and ovarian steroid-producing cells; 3) The histological picture of the ovaries of such cases (lymphoplasmacellular infiltrate around steroid-producing cells); 4) The existence of various autoimmune animal models for this syndrome, which underlines the autoimmune nature of the disease. There is some circumstantial evidence for an autoimmune pathogenesis in idiopathic POF patients in the absence of adrenal autoimmunity or Addison's disease. Arguments in support of this are: 1) The presence of cellular immune abnormalities in this POF patient group reminiscent of endocrine autoimmune diseases such as IDDM, Graves' disease, and Addison's disease; 2) The more than normal association with IDDM and myasthenia gravis. Data on the presence of various ovarian autoantibodies and anti-receptor antibodies in these patients are, however, inconclusive and need further evaluation. A strong argument against an autoimmune pathogenesis of POF in these patients is the nearly absent histological confirmation (the presence of an oöphoritis) in these cases (< 3%). However, in animal models using ZP immunization, similar follicular depletion and fibrosis (as in the POF women) can be detected. Accepting the concept that POF is a heterogenous disorder in which some of the idiopathic forms are based on an abnormal self-recognition by the immune system will lead to new approaches in the treatment of infertility of these patients. There are already a few reports on a successful ovulation-inducing treatment of selected POF patients (those with other autoimmune phenomena) with immunomodulating therapies, such as high dosages of corticosteroids (288-292).

Mathematical formulae for the prediction of the residual beta cell function during the first two years of disease in children and adolescents with insulin-dependent diabetes mellitus

On the basis of a retrospective study of 71 children followed for 24 months after diagnosis of type I insulin dependent diabetes a fitted mathematical model was constructed for the prediction of the course of beta cell function from the time of diagnosis. Two equations were derived, one for the maximal basal (B-max) and the other for the maximal i.v. glucagon stimulated peak C-peptide (P-max) levels reached during the remission period. The prognostic variables selected for analysis were: peak C-peptide levels at diagnosis (Po), age sex, degree of obesity, pubertal rating, the presence of islet cell antibodies (ICA) and levels of GHb. Multivariate analysis of the data showed that Po (p = 0.0006), puberty (p = 0.041). obesity (p = 0.0021), sex (p = 0.031), ICA (p = 0.0045) and GHb(p = 0.0066) significantly contributed to the prediction formula obtained for B-max whereas the contribution of the above variables for P-max were: Po (p = 0.0019), puberty (p = 0.0187), obesity (p = 0.0058), sex (p = 0.0598), ICA (p = 0.0187) and GHb (p = 0.0027). The residuals of the observed values from the values fitted by the predicted equations served to define two separate groups demonstrating distinct differences in the natural course of beta cell function in type I diabetes. This fitted model may thus be useful in distinguishing between newly diagnosed young patients who will undergo remission, requiring lower insulin doses, and those who have little chance for remission. It might also be helpful in the selection of patients most likely to benefit from immunosuppression or modulation, to maximize the benefit to risk ratio for such patients.

Analysis of peripheral blood lymphocyte subsets, NK cells, and delayed type hypersensitivity skin test in patients with premature ovarian failure

PROBLEM

Premature ovarian failure (POF) probably belongs to the group of autoimmune endocrinopathies. Cell-mediated immune parameters were investigated. Sex steroids have a profound effect on the immune system. POF patients and postmenopausal control women (PM) were tested with or without estrogen substitution.

METHOD

A novel FACS analysis system (using double labeling techniques) was used in 30 patients with POF to enumerate the subjects of peripheral blood lymphocytes and NK cells. Eighteen PM women and 30 healthy men and women served as controls. We also tested the delayed type hypersensitivity skin test (DTH) toward Candida in the POF patient group to be informed on their cell-mediated immune function.

RESULTS

The numbers of blood lymphocytes, CD3+, CD4+ and CD8+T cells, were not abnormal in POF patients. However, HLA-DR+T cells were increased in POF patients and in PM women (P < 0.05). These elevated numbers were partially reversible by estrogen substitution. The number of CD19+ cells (B cells) was elevated, whereas CD3-/CD16+/CD56+ cells (NK cells) were decreased in POF patients (P < 0.05), irrespective of estrogen substitution. DTH skin tests toward 0.1% Candidin (0.1 ml intradermal injection) were negative in 11 out of 20 tested POF patients, compared to only 2 out of 10 tested controls (P < 0.05).

CONCLUSION

POF patients show numerous immune cell abnormalities. These abnormalities were only partially due to estrogen deficiency. We hypothesize that these abnormalities either lead to ovarian autoimmunity or may have direct effects on the ovarian function.

Therapy of streptozotocin induced diabetes with a bifunctional antibody that delivers vinca alkaloids to IL-2 receptor positive cells

IVA039.1 is a bifunctional antibody with specificity for the murine IL-2 receptor and vinca alkaloids. Biodistribution studies show that IVA039.1 can target and deliver vinca alkaloids to tissues that contain IL-2 receptor positive cells. Vinca alkaloids are lymphocytotoxic. Therapy of diabetic mice with IVA039.1 plus vincristine results in a significant decrease in the glucose levels of diabetic compared to untreated mice. The therapeutic effect of IVA039.1 plus vincristine therapy was additive but surprisingly not synergistic. The binding of IVA039.1 to vincristine has moderate affinity with a slow off rate. In vitro studies suggest that, when bound to IVA039.1, the vincristine is inactivated. We attribute the lack of an enhanced therapeutic response to bifunctional antibody therapy using IVA039.1 plus vincristine to the inaccessibility of the drug to the target cells.

T lymphocyte activation in Graves' disease

We examined the proliferative response of T lymphocytes from thirty-eight patients with Graves' disease (17 untreated thyrotoxic and 30 euthyroid on antithyroid medication) to phytohemagglutinin, anti-CD3 MoAb and phorbol esters, as well as the capacities of these lymphocytes to produce interleukin 2 and the density of interleukin 2 receptors and major histocompatibility class II antigens. We found that the response of T lymphocytes to phytohemagglutinin, anti-CD3 monoclonal antibody and phorbol esters from untreated thyrotoxic Graves' disease was significantly enhanced as compared to treated patients and normal controls. Interleukin 2 production by mitogen-triggered T lymphocytes in both treated and untreated patients with Graves' disease was comparable to that of the control population. Interleukin 2 receptor density was found to be normal, whereas that of human leukocyte antigen-DR was increased in both untreated and treated patients. Following lymphocyte stimulation, there was an increase in human leukocyte antigen-DR and interleukin 2 receptor expression in patients with untreated Graves' disease. Significant correlations were found between thyroid hormone concentration and the proliferative responses to the polyclonal mitogen phytohemagglutinin, anti-CD3 monoclonal antibody and phorbol esters in untreated Graves' patients. Furthermore, during the follow-up of 9 patients, attainment of normal thyroid function after antithyroid treatment was associated with a decrease in and normalization of T-proliferative responses. Our data reveal that active Graves' disease is associated with T cell activation and this is probably related to immunological dysregulation as well as to hyperthyroxinemia.

Importance of persistent cellular and humoral immune changes before diabetes develops: prospective study of identical twins

OBJECTIVES

To determine the pattern of cellular and humoral immune changes associated with insulin dependent diabetes before diabetes develops.

DESIGN

Prospective study over 10 years of 25 non-diabetic identical twins of patients with insulin dependent diabetes. The non-diabetic twins were followed up either till they developed diabetes or to the end of the study.

SETTING

Teaching hospital.

SUBJECTS

25 non-diabetic identical cotwins of patients with diabetes; 46 controls of the same sex and similar age tested over the same period. Of the 25 twins (total follow up 144 patient years), 10 developed diabetes (prediabetic twins); the remainder were followed up for a mean of 7.7 years.

MAIN OUTCOME MEASURES

Results of glucose tolerance tests or fasting blood glucose concentrations at each sample point. Measurements of activated T lymphocytes, expressing the HLA-DR antigen, islet cell antibodies, and insulin autoantibodies in samples.

RESULTS

All 10 prediabetic twins had both cellular and humoral changes initially and in most samples before diabetes was diagnosed (activated T lymphocytes in 39/40, islet cell antibodies in 45/47, and insulin autoantibodies to islet cells and insulin were detected infrequently (in 8/54, 6/69, and 0/69 samples, respectively). The combination of cellular and humoral (islet cell antibodies or insulin autoantibodies) immune changes were detected in all 10 of the prediabetic twins but in only one of the 15 non-diabetic twins (P < 0.001). The positive predictive value in this cohort of increased percentages of activated T cells and the presence of antibodies to islet cells or insulin on two consecutive occasions was 100%.

CONCLUSION

Most of the twins had cellular or humoral immune changes at some stage. A combination of cellular and humoral immune changes and their tendency to persist is highly predictive of insulin dependent diabetes and distinguishes twins who develop diabetes from those who do not.

Production and in vivo characterization of a bifunctional antibody (IVA039.1) with specificity for the mouse interleukin-2 receptor and vinca alkaloids

The autoreactive T cell plays a pivotal role in the pathogenesis of type I diabetes in humans and in rodent animal models. Elimination or attenuation of these cells may provide a means to treat the disease. The use of antibodies directed to T cells has shown varying degrees of effectiveness in the treatment of autoimmune disease. The use of a bifunctional antibody directed to T cells with a cytolytic agent may provide an additional level of therapeutic efficacy compared to anti-T-cell antibodies alone. To test this hypothesis, we prepared a bifunctional antibody (IVA039.1) with specificity for the mouse interleukin-2 (IL-2) receptor and vinca alkaloids. The antibody was derived from the fusion of vinca immune spleen cells with PC61 5.3, a hybridoma that produces rat anti-mouse IL-2 receptor antibody. IVA039.1 was purified by affinity chromatography through Protein A and anti-vinca affinity columns followed by TSK-DEAE high-pressure liquid chromatography (HPLC). Bifunctionality of the antibody was confirmed by fluorescence-activated cell sorting (FACS) analysis, enzyme-linked immunoadsorbent assay (ELISA) and a cell assay designed to measure simultaneously both IL-2 receptor and vinca reactivities. The biodistribution of IVA039.1 was determined in normal and streptozotocin-complete Freund's adjuvant (CFA) induced diabetic mice. Enhanced uptake of IVA039.1 was observed in the pancreata, spleens, and lymph nodes of diabetic compared to normal mice. These data suggest that bifunctional antibodies that can deliver cytolytic agents to T cells may be appropriate candidates for the treatment of diabetes and other autoimmune diseases.

Cutaneous manifestations of diabetes mellitus

Diabetes mellitus (DM) is a heterogeneous group of disorders characterized by a high serum glucose level and by disturbances of carbohydrate and lipid metabolism. It is estimated that 11 million persons in the United States have DM, 90% of whom have non-insulin-dependent DM. At least 30% of persons with diabetes have some type of cutaneous involvement during the course of their chronic disease. This review classifies the cutaneous findings in DM into four categories: (1) skin diseases with strong to weak association with DM; (2) cutaneous infections; (3) cutaneous manifestations of diabetic complications; and (4) skin reactions to diabetic treatment. Each of these categories is reviewed as well as the pathophysiology of the normal and diabetic basement membrane for a better understanding of the cutaneous manifestations of DM.

Evidence for different clinical subtypes of type 1 diabetes mellitus: a prospective study

The purpose of this study was to determine whether the sex, age, severity of clinical presentation, presence of ICAs, IAs, and HLA-DR and DQ types could predict, in a cohort of newly-diagnosed diabetic children: (1) the duration of beta-cell function as measured by C-peptide response to a Sustacal meal; and (2) determine if those predictors could identify disease subtypes. A cohort of 170 consecutive patients was followed for 60 months after diagnosis. We found that age (0.0029), sex (0.0136), ICA (0.0001), presence of DKA (0.0070) and C-peptide peak at diagnosis (0.0000) significantly predicted the duration of residual beta-cell function over time. Furthermore, C-peptide secretion at diagnosis, presence of ICA, age and sex allowed the identification of three different prognostic groups with varying acceleration of beta-cell loss.

Lymphocyte subset abnormalities, autoantibodies and their relationship with HLA DR types in children with type 1 (insulin-dependent) diabetes and their first degree relatives

Type 1 (insulin-dependent) diabetes mellitus is associated with abnormalities of circulating lymphocyte subsets and autoantibodies. To investigate the prevalence of these in non-diabetic siblings and non-diabetic patients of children with Type 1 diabetes, we analysed T-cell subsets of function and activation in 31 families with an index case of Type 1 diabetes and related these to autoantibodies and HLA DR type. Using two and three colour cytofluorimetry, we studied total and activated (HLA-DR+) CD3+, CD4+, CD8+, lymphocytes and on CD4+ lymphocytes the CD45RA/RO "naive" and "memory" cell phenotypes. Diabetic children (mean duration of disease 3.1 years) had a reduced total lymphocyte count (p < 0.05), their non-diabetic siblings a reduced CD4+ T-helper cell count (p < 0.05), and their parents a reduced percentage and number of CD3+ T cells (p < 0.01 and p < 0.05) compared with age-matched control subjects. Diabetic children, their siblings and parents all had significantly increased levels of activated CD4+ T-helper cells (p < 0.01, p < 0.05 and p < 0.01). In diabetic children and their siblings there was a significant over-expression of the CD45RO "memory" cell marker and significant under-expression of the CD45RA "naive" cell marker, whilst these were normal in the parents. Islet cell antibody positive diabetic children had significantly higher levels of CD45RO-expressing CD4+ lymphocytes than those who were islet cell antibody negative (p < 0.05). Amongst the siblings and parents, possession of HLA-DR4 was associated with lower percentages of CD4+ and higher percentages of CD8+ T cells. These findings extend current knowledge about the role of immunoregulatory CD45RA/RO cells in Type 1 diabetes. In addition, they demonstrate lymphocyte subset abnormalities in unaffected family members, some of which may be influenced by HLA DR alleles.

T cell clones generated from patients with type 1 diabetes using interleukin-2 proliferate to human islet antigens

T lymphocytes are implicated in the pathogenesis of Type 1 (insulin dependent) diabetes. Activated T lymphocytes expressing IL-2 receptors are found at increased levels in the peripheral blood in the prediabetic period, at diagnosis and for several months after the onset of the disease, but their role in the pathogenesis of the disease is not known. We have used co-culture of peripheral blood lymphocytes with IL-2 alone to selectively generate T cell clones from the in vivo activated T cell population, and examined the phenotype and antigen specificity of the clones derived. From 3 patients with newly-diagnosed Type 1 diabetes 184 clones were generated, the majority of which (39%) were CD4+TCR alpha beta+, whilst 31% were CD8+TCR alpha beta+. From 2 healthy control subjects 90 clones were obtained, of which 62% were CD4+TCR alpha beta+ and 33% were CD8+TCR alpha beta+. Antigen specificity was examined in 46 clones from the patients and 44 from the control subjects in proliferation assays, using as antigens homogenate of human islets of Langerhans, human islet membrane preparation and human liver membrane preparation. Three clones (all CD4+TCR alpha beta+) from the patients, but none from the control subjects, proliferated in a dose dependent fashion in response to stimulation with human islet homogenate presented by autologous APCs, but to neither of the other autoantigen preparations. Our results demonstrate that a relatively high proportion (7%) of T lymphocytes activated in vivo recognise human islet antigens, indicating that they may have a role in the pathogenesis of the disease.

Seasonal variation and sex differences of circulating macrophages, immunoglobulins and lymphocytes in healthy school children

Subpopulations of T and B lymphocytes and levels of serum immunoglobulins G, A, M, E and subclasses G1, G2 and G3 were studied in 45 healthy school children aged 8-16 years during four seasons of the year. There were significant increases in CD4+ T helper cells, total T lymphocytes and CD4+/CD8+ (helper/cytotoxic) T-cell ratio during the spring season. While the levels of CD8+ T cells and total B lymphocytes remained statistically unchanged during all four seasons, the levels of natural (HNK-1) killer cells and macrophages increased significantly during the autumn and summer seasons respectively. The levels of immunoglobulins G, A, M and E remained statistically unchanged during all four seasons. Girls had higher levels of CD4+ T cells and a higher CD4+/CD8+ T-cell ratio than boys. Girls also had slightly higher levels of immunoglobulin G and M. These observations suggest that seasonal variations of some immunological parameters occur in healthy children. This may be an adaptive response to variable climatic and other environmental factors. These natural variations due to seasonal changes should be taken into account when immunological tests are used in clinical investigations.

Study of T-cell activation in type I diabetic patients and pre-type I diabetic subjects by cytometric analysis: antigen expression defect in vitro

In Type I diabetes the observation of a decreased release of interleukin-2 (IL-2) and soluble IL-2 receptors by means of stimulated lymphocytes in vitro indicates that a primary immunoregulatory defect may be involved. To confirm this hypothesis we investigated the T-cell activation trend, evaluating the surface expression of IL-2 receptor (CD25), transferrin (CD71), HLA class II (DR), and CD69 phenotypes after in vitro stimulation with phytohemagglutinin (PHA; 1 and 10 micrograms/ml) and concanavalin A (12.5 micrograms/ml) in six newly diagnosed Type I diabetics and six islet cell- and insulin autoantibody-positive first-degree relatives. As controls were studied six long-standing Type I diabetics and six healthy subjects. T-cell cultures from the four groups were performed on the same day and examined at 0, 24, 48, 96, 120, and 144 hr. Cytometric analysis was performed, keeping PBMC gating constant on the basis of physical parameters (scatter and volume). Using both PHA concentrations, a lower level of CD25, CD71, CD69, and DR antigen expression was found in newly diagnosed patients at all observation times with respect to control cultures (P < 0.001). Unexpectedly, pre-Type I diabetic subjects, after 1 microgram/ml of PHA, showed a significantly reduced expression of CD69 (P < 0.001) and CD71 (P < 0.001). The levels remained low, also with high PHA, at the different observation periods, while CD25 expression was found to be reduced in prediabetics only after 1 micrograms/ml of PHA (P < 0.001). The long-standing patients showed a T cell activation trend very close to the latter. Our data show that in Type I diabetes and in the early phases of the disease, the initial activation signal(s) appears to be affected, particularly with one or more subsequent events necessary to initiate the appearance of "activation antigens." This study suggests that the natural history of immunoregulation in pre-Type I and Type I diabetes is characterized by a primary defect in this system, which also persists in patients with long-standing disease.

Analysis of T-lymphocyte subsets after phytohemagglutinin stimulation in normal and type 1 diabetic mothers and their infants

PROBLEM

Our aim was to investigate the immunological status of diabetic pregnancy, which is an overlap of diabetic immunity abnormalities and the immunological modifications normally occurring during pregnancy.

METHOD

We studied lymphocyte subpopulations and lymphokine production, after 96 h of phytohemagglutinin (PHA) stimulation, from normal and Type I diabetic pregnant women at delivery time and from the respective cord blood.

RESULTS

Peripheral blood mononuclear cells (PBMC) from both normal and Type I diabetic mothers showed an increase in CD8+ and a decrease in CD4+ cells compared to the respective cord blood mononuclear cells (CBMC). Moreover, Type I PBMC showed a lower number of "activated" CD3+ DR+ cells and a higher number of CD8+ CD25+ cells with respect to normal women, which may reflect the dysregulatory pattern due to the autoimmune condition. Type I CBMC showed a big increase in the number of CD4+ Leu8+ cells, a cell subpopulation characterized by inhibitory activity. Finally, as regards lymphokine release in culture supernatants, type I diabetes seemed to be associated with an over-production of IL1 and IL6, although the latter increase is less evident in CBMC cultures.

CONCLUSIONS

The present study shows that diabetic pregnancy is associated with major alterations of cell-mediated immunity leading to a state of immunodepression. Moreover, our study suggests that the maternal immunological status influences fetal immunity, as demonstrated by the increase in the number of regulatory cells and by the altered pattern of lymphokine production (IL1 and IL6) by lymphocytes derived from diabetic CBMC. The latter phenomenon perfectly mirrors maternal PBMC characteristics.

Anti-endothelial cell antibodies in insulin-dependent diabetes mellitus

The prevalence of IgG class antibodies to endothelial cells (AECA) was studied in 136 young patients with insulin-dependent diabetes mellitus by an enzyme immunoassay using human umbilical cord vein endothelial cells. The patients were divided into four groups according to the time between diagnosis and study and their results were compared with those in control children and blood donors. AECA became progressively more frequent with the duration of diabetes, being 4% in diabetics tested within 2 weeks of diagnosis and reaching 34% after an average disease duration of 11.2 years. They were not more common in patients with neuropathy, retinopathy or nephropathy than in patients without these complications, but were associated with co-existing thyroid disease and IgA deficiency. The results suggest that in insulin-dependent diabetes mellitus AECA are associated with co-existing autoimmune disorders but not with diabetic microvascular disease.

Immunological monitoring in organ transplantation and autoimmune disease

The clinical manifestations of graft rejection or autoimmune disease represent the terminal phase in a complex sequence of inflammatory events. Although the spectrum of response to injury within each tissue is normally narrowly defined, the immune mechanisms involved may be heterogeneous, influenced by the immune status of the host, the nature of the stimulus (i.e. viral antigen, allostimulation, or aberrant recognition of self), and the use of exogenous immunosuppression. Within this framework, immunological monitoring is employed to distinguish the causative effector mechanisms, to characterize the disease course, to tailor therapeutic intervention, and to monitor treatment impact in individual immunological disorders.

A comparative study of antigen expression by skin and pancreas in the prediabetic and diabetic state of the BB rat

Type 1, insulin-dependent diabetes mellitus is an autoimmune disease with destruction of beta-cells in islets of Langerhans by activated (antigen-positive) infiltrating mononuclear cells accompanied by serological immune phenomena. The pathological mechanism has not yet been clarified in detail, and some inversion in the proportion of epidermal antigen expression has recently been described in spontaneous diabetes. The BB rat is one of the animal models most closely resembling human type 1 diabetes of autoimmune origin. We compared the class I and class II antigen expression in the islets of Langerhans and in the skin of spontaneously diabetic (BBD) and normoglycaemic (BBND) BB rats in the prediabetic, diabetic and non-diabetic states. Class I and class II antigen expression increased significantly in the islets of BBD rats from prediabetes to diabetes and compared with non-diabetic controls. In the same period, the dermal antigen expression (class I and class II) did not decrease and was not lower in BBD than in BBND animals. These results do not support a loss of activated (antigen-positive) dermal cells at the onset of diabetes in the BB rat and do not show a clear correlation with the antigen expression in infiltrated islets of Langerhans.

Abnormalities within CD4 and CD8 T lymphocytes subsets in type 1 (insulin-dependent) diabetes

Abnormalities in the proportions of various T lymphocyte subpopulations have been found in a number of autoimmune diseases. Monoclonal antibodies labelled with various fluorochromes were used here to define the percentages of subsets, and especially to divide CD4+ (helper/inducer) and CD8+ (suppressor/cytotoxic) cells into phenotypic subgroups. Blood samples were analysed from 25 patients (age 10.1 +/- 3.7 years) with recently diagnosed insulin-dependent diabetes mellitus (IDDM) and 25 age- and sex-matched control subjects. The percentages of CD4+ cells and CD4+CD45RA+ cells described as naive T helper cells or suppressor/inducers were increased in the IDDM patients (P less than 0.05 and P less than 0.05. Student's t-test, respectively), whereas the percentage of CD4+CD45RA- cells (memory T-helper cells, helper/inducers) was similar in the patients and controls. The percentage of CD8+CD11b+ cells containing suppressor/effector lymphocytes was decreased in the IDDM patients as compared with the controls (P less than 0.01) but no significant difference was seen in total CD8+ cells. The percentages of CD3+ cells and the proportions of these simultaneously positive for HLA-DR antigen (activated T cells) were also increased in the recent IDDM patients (P less than 0.001 and P less than 0.05, respectively), while the proportion of CD20+ B cells was decreased (P less than 0.05). The findings support the view that disturbed immune regulation occurs in IDDM and indicate that further division of T cell subpopulations may clarify our understanding of the disease process.

Increased peripheral T lymphocyte activation in patients with karyotypically normal spontaneous premature ovarian failure

OBJECTIVE

To determine if soluble interleukin 2 (IL-2) receptor measured in serum by an enzyme-linked immunosorbent assay (ELISA) might be useful in managing patients with karyotypically normal spontaneous premature ovarian failure.

DESIGN

Prospective, controlled observation.

SETTING

Tertiary care research institution.

INTERVENTIONS

None.

PATIENTS, PARTICIPANTS

Twenty-four patients with karyotypically normal spontaneous premature ovarian failure comprised the study group. Forty-two healthy men and women comprised the normal reference group.

MAIN OUTCOME MEASURES

We measured peripheral T lymphocyte human leukocyte antigen locus-DR (HLA-DR) expression and IL-2 receptor expression using monoclonal antibodies and flow cytometry. We measured soluble IL-2 receptor levels in serum using an ELISA.

RESULTS

Consistent with previous findings, our patients had significantly higher HLA-DR expression on peripheral T lymphocytes (5.3 +/- 0.46) as compared with controls (3.5 +/- 0.34) (mean +/- SEM, P less than 0.01). Seven patients also had elevated IL-2 receptor expression on peripheral T lymphocytes (P less than 0.05). However, soluble IL-2 receptor levels in the serum did not differ significantly from normals.

CONCLUSIONS

Patients with karyotypically normal spontaneous premature ovarian failure have a modest increase in peripheral T lymphocyte activation measured by flow cytometry. This degree of activation does not result in increased soluble IL-2 receptor release measured by ELISA.

Immune activation and T cell subset abnormalities in circulation of patients with recently diagnosed type I diabetes mellitus

The peripheral blood lymphocytes from patients with insulin-dependent diabetes mellitus (IDDM) and healthy controls were analysed for the HLA-DR+, interleukin-2 receptor-positive (IL-2R+) activating antigens, and for CD45R+ and CDw29+ subsets from the purified CD4+ and CD8+ T cells populations. Patients with IDDM had an increased percentage of HLA-DR+ and IL-2R+ cells in both CD4+ and CD8+ T cells. However, the percentage of CD4+ CD45R+ suppressor/inducer T cells were decreased and CD4+ CDw29+ helper/inducer T cells increased in all patients with IDDM, compared with healthy controls. Thus, IDDM patients exhibit a deficiency in the CD4+ CD45R+ suppressor/inducer T cell subsets, which is probably related to the autoimmune phenomenon in this disease. In contrast, the percentage of CD8+ CDw29+ T cell subsets showed no major differences between patients with IDDM and controls. An alteration in the CD4+ CD45R+ and CD4+ CDw29+ T cell subsets appears to be a characteristic feature, and may relate to the impaired cell-mediated immunity in IDDM. These data provide new evidence for T cell dysregulation in IDDM.

MHC-linked protection from diabetes dissociated from clonal deletion of T cells

The I-E molecule of the major histocompatibility complex (MHC) can prevent the spontaneous development of diabetes in nonobese diabetic (NOD) mice. The mechanism of this protection has been investigated by breeding wild-type and promoter-mutated E kappa alpha transgenes onto the NOD genetic background. Animals carrying the various mutated transgenes expressed I-E on different subsets of immunocompetent cells, and thus cells important for the I-E protective effect could be identified. Although the wild-type transgene prevented the infiltration of lymphocytes into pancreatic islets, none of the mutants did. However, all of the transgenes could mediate the intrathymic elimination of T cells bearing antigen receptors with variable regions that recognize I-E. Thus, the I-E molecule does not protect NOD mice from diabetes simply by inducing the deletion of self-reactive T cells.

Immune activation and autoantibodies in humans with long-term inhalation exposure to formaldehyde

Four groups of patients with long-term inhalation exposure to formaldehyde (HCHO) were compared with controls who had short-term periodic exposure to HCHO. The following were determined for all groups: total white cell, lymphocyte, and T cell counts; T helper/suppressor ratios; total Ta1+, IL2+, and B cell counts; antibodies to formaldehyde-human serum albumin (HCHO-HSA) conjugate and autoantibodies. When compared with the controls, the patients had significantly higher antibody titers to HCHO-HSA. In addition, significant increases in Ta1+, IL2+, and B cells and autoantibodies were observed. Immune activation, autoantibodies, and anti-HCHO-HSA antibodies are associated with long-term formaldehyde inhalation.

Identification of susceptibility loci for type 1 (insulin-dependent) diabetes by trans-racial gene mapping

A major component of inherited susceptibility to Type 1 (insulin-dependent) diabetes mellitus has been mapped to the major histocompatibility complex. Certain gene alleles in this region determine susceptibility and resistance to the disease. Mapping of susceptibility is hindered by the limitations of conventional tissue typing techniques, and by strong linkage disequilibrium within this part of the genome. Recombinant DNA technology and trans-racial studies have been used to allow finer mapping of genetic predisposition to Type 1 diabetes. These techniques have localised alleles encoding susceptibility and resistance to the DQ region. Other alleles determining disease susceptibility remain poorly localised.

Immune responses to insulin and lymphocyte subclasses at diagnosis of insulin-dependent diabetes and one year later

Insulin induced proliferation of blood mononuclear cells, numbers of blood B and T cells, of blood lymphocytes bearing interleukin 2 receptors or HLA class II molecules were assayed at diagnosis and one year later in children with insulin-dependent diabetes mellitus (IDDM) and in healthy children. Insulin and islet cell antibodies were also studied. The numbers of lymphocytes expressing HLA class II molecules and NK cells were increased at diagnosis. T cells of the helper/inducer (CD4+) phenotype and interleukin 2 receptor positive lymphocytes were increased both at diagnosis and one year later. At diagnosis, insulin induced proliferation of blood mononuclear cells in 65% and one year later in 50% of the patients. Insulin antibodies were detected in 10% and islet cell antibodies in 90% of patients at diagnosis, and in 67% and 78%, respectively, one year later.

Effect of initiation of insulin therapy on T-lymphocyte activation in type 1 diabetes

Levels of activated T-lymphocytes are characteristically increased in recently diagnosed patients with Type 1 diabetes and remain elevated up to 6 months after diagnosis. To determine whether insulin treatment has a role in initiating or maintaining this activation 12 patients were studied at diagnosis and again 1, 5, and 70 days after the start of insulin therapy. Levels of activated T-lymphocytes were found to be elevated at diagnosis (9.7 +/- 1.6% (+/- SD)) before insulin treatment compared with normal control subjects (4.2 +/- 1.1%; p less than 0.001). One day after starting insulin therapy, the level of activated T-lymphocytes had not changed but by day 5 it had fallen significantly (7.6 +/- 1.9%; p less than 0.05) compared with pre-treatment levels. By day 70, activated T-lymphocytes were returning towards the high levels found before treatment. Investigation of the phenotype of the activated T-lymphocytes showed that there was an increase in the percentage of activated cells expressing the CD8 (suppressor/cytotoxic) phenotype at 70 days compared with pre-treatment values (p less than 0.02). These results show that elevated levels of activated T-lymphocytes found in recently diagnosed Type 1 diabetes are not a result of insulin treatment. Treatment may, however, have a role in maintaining T-lymphocyte activation and modifying the distribution of functional subsets of the activated cells.

Immunogenetics of early-onset insulin-dependent diabetes mellitus among the Japanese: HLA, Gm, BF, GLO, and organ-specific autoantibodies--the J.D.S. study

The Japan Diabetes Society (JDS) conducted a multicenter study on the immunogenetics of early-onset insulin-dependent diabetes mellitus (IDDM) of the Japanese. Human leukocyte antigen (HLA), properdin factor B (BF), immunoglobulin heavy-chain complex (Gm), and glyoxalase of erythrocytes (GLO) were typed, and organ-specific autoantibodies, including islet cell antibody (ICA), were assayed in 159 Japanese IDDM patients and their family members and in 258 healthy Japanese controls. The HLA-DRw9 phenotype and HLA-Bw61/DRw9 haplotype were significantly increased among the patients with autoantibodies other than ICA but with no autoimmune diseases (RR = 5.84, cP less than 0.001; and RR = 7.45, P less than 0.001), whereas the HLA-DR4 phenotype and HLA-Bw54/DR4 haplotype were significantly increased in those without either the autoantibodies or autoimmune diseases (RR = 2.64, cP less than 0.001; and RR = 4.55, P less than 0.001). The HLA-DR4 phenotype was significantly increased in the patients with autoimmune thyroid diseases (RR = 6.21, cP less than 0.05). In all groups of patients, the HLA-DR2 phenotype was significantly decreased, and the relative risk of the HLA-DRw9/DR4 genotype was highest among all HLA-DR genotypes. No significant association was found between HLA type and the duration or incidence of ICA. Gm types of g and gft were significantly increased in the patients with the autoantibodies (RR = 2.11, P less than 0.05; and RR = 34.11, P less than 0.05), whereas the BF-F phenotype was significantly decreased in the patients either with or without autoantibodies (RR = 0.43, P less than 0.05; and RR = 0.46, P less than 0.05). There was no association between IDDM and GLO type. These data indicate that immunogenetic bases underlying IDDM of the Japanese are heterogeneous, as are those in Caucasians.

Activated CD4-positive T-lymphocytes and impaired cell-mediated immunity in patients with carcinoma of the urinary bladder with schistosomiasis

Patients with schistosomiasis of the urinary bladder (SB) associated with carcinoma of the bladder (SCB) or carcinoma of the prostate (SCP) have a variety of immunologic abnormalities, including the presence of HLA-DR+ and interleukin-2 receptor-positive (IL-2R+) T-lymphocytes in circulating blood. This study demonstrated that, the HLA-DR+ and IL-2R+ antigens are selectively expressed on majority of the CD4+ T-lymphocytes of patients with SCB, whereas, these antigens are expressed almost equally on both CD4+ and CD8+ T-lymphocytes of patients with SB and SCP. Expressions of HLA-DR+ and IL-2R+ antigens in CD4+ T-lymphocytes, and a depressed response of this T-cell subset to phytohemagglutinin and Concanavalin A stimulations seems to be the characteristic feature of these patients with SCB. In addition, the autologous mixed lymphocyte reaction (AMLR) and allogenic mixed lymphocyte reaction (MLR) was depressed in patients with SCB. However, patients with SCP demonstrated a normal MLR, even though the AMLR was highly depressed. The immunoregulatory role of the HLA-DR+, IL-2R+, CD4+ helper/inducer T-lymphocytes, and the AMLR and MLR abnormalities we have identified in patients with SCB may be important and could play a role in the pathobiology of these diseases in humans.

Increased circulating HLA-DR+ CD4+ T cells in systemic lupus erythematosus: alterations associated with prednisolone therapy

Patients with active systemic lupus erythematosus (SLE) in the circulation have a selective increase of a subset of the CD4+ helper/inducer T cells bearing HLA-DR+, major histocompatibility complex class II antigens. We studied prednisolone-induced alterations of HLA-DR+, CD4+, and CD8+ T-cell subsets in three patients with active SLE. Prednisolone therapy was accompanied by a drastic reduction in circulating HLA-DR+, CD4+ T-cell subsets, serum anti-DNA titre, normalization of the serum immunoglobulin profile, and CD4+ T-cell responses to phytohaemagglutinin and concanavalin A. These changes in immune functions were associated with eventual improvement in the clinical condition of active SLE. A low percentage of HLA-DR+, CD8+ T-cell subsets was present in the circulation, which was not changed by prednisolone therapy. These results suggest that HLA-DR+, CD4+ T-cell subsets play a major role in the pathogenesis of active SLE, and that prednisolone-induced immunosuppression in this disease is mediated by changes in the HLA-DR+, CD4+ T-cell subsets in circulating blood.

Activated CD4+ and CD8+ T-lymphocytes in newly diagnosed type 1 diabetes: a prospective study

Peripheral lymphocytes from 13 Type 1 diabetic patients (age 28 +/- 11 (+/- SD) years) were studied at diagnosis, and 1 month and 7 months later. The lymphocytes were labelled with phycoerythrin-conjugated anti-HLA-DR antibody and/or fluorescein-conjugated OKT4 or OKT8 antibody, and then studied using a double channel flow-cytometer. The overall percentage of activated T-lymphocytes (CD4+ + CD8+ cells) was (mean +/- SE) 3.1 +/- 0.5% at diagnosis, 2.1 +/- 0.3% at 1 month and 2.2 +/- 0.5% at 7 months test. The percentages at diagnosis and 1 month were higher than in 12 healthy control subjects (1.0 +/- 0.2%, p less than 0.001 and p less than 0.01, respectively). Among the CD4+ cells the percentage of activated cells fell from diagnosis (2.8 +/- 0.7%), to 1 month (1.5 +/- 0.3%, p less than 0.05), and 7 months (1.5 +/- 0.4%, p less than 0.05), whereas among the CD8+ cells they remained unchanged (3.3 +/- 0.6, 2.5 +/- 0.5 and 3.1 +/- 0.6%). The percentage of activated CD4+ cells at diagnosis, and of CD8+ cells at all times, were higher (p less than 0.02) than in control subjects (CD4+, 0.8 +/- 0.2%; CD8+, 1.2 +/- 0.2%). In conclusion, the activated T-lymphocytes present in Type 1 diabetic patients at diagnosis are equally increased among CD4+ and CD8+ cells, but after 7 months the increase is predominantly in CD8+ cells.

Increase in activated T cells and reduction in suppressor inducer T cells in systemic sclerosis

Blood lymphocytes from 37 patients with systemic sclerosis were characterised using monoclonal antibodies in a two colour flow cytometric (fluorescence activated cell sorter (FACS)) analysis. The ratio of helper CD4+ to suppressor/cytotoxic CD8+ T cells was raised in patients compared with that in 30 healthy controls owing to decreased CD8+ cells. In the patients CD4+ and CD8+ cells displayed an increased expression of the activation marker HLA-DR. The relative number of CD11b+ CD8+ lymphocytes (suppressor T cells) was normal, but the calculated absolute counts of this cell type were slightly reduced. The proportions and absolute numbers of suppressor inducer T cells, defined as CD45R+ CD4+ cells, were on average only half the levels observed in controls. These findings were not related to the inflammatory activity as measured by acute phase plasma proteins or serum immunoglobulins. Activated T cells were seen at all stages of the sclerotic process and especially during the early stages of the disease and in patients who had suffered occupational exposure to silica dust. A high proportion of activated T cells was also linked with impaired small intestine function but not with the degree of skin or lung involvement. A loss of suppressor inducer T cells was more pronounced later in the disease and in patients with the CREST (calcinosis, Raynaud's phenomenon, oesophageal dysmotility, sclerodactyly, telangiectasia) syndrome. These data provide further evidence for an involvement of T cell mediated immunity in the perpetuation of systemic sclerosis.

Increased interleukin 2 receptor expression in post-gestational women: relationship to impaired glucose tolerance and islet cell antibodies in pregnancy

Fifteen women with positive islet cell antibodies were identified in a group of 115 consecutive patients found to have impaired glucose tolerance in pregnancy. These subjects were postulated to be at increased risk of later developing type 1 diabetes mellitus. They were examined post--partum for HLA types known to be associated with this disease and for any increase in Interleukin 2 receptor expression or alteration of T cell subsets of possible relevance to its pathogenesis. Fifteen women negative for islet antibodies and with normal glucose tolerance during previous pregnancy and 15 women with a normal fasting plasma glucose who had never been pregnant were studied as controls. Using flow cytometric techniques a significant increase in both the number and proportion of activated (Interleukin 2 receptor, CD25) lymphocytes in the peripheral blood of women who had islet cell antibodies and previous impaired glucose tolerance in pregnancy was found (0.14 +/- SE 0.03 x 10(9)/l; 7.1 +/- 1.1%) when compared with normal parous controls (0.09 +/- 0.01 x 10(9)/l; 4.2 +/- 0.6%), p less than 0.01 x 10(9)/l; showed significant increases when compared with nulliparous controls (0.04 +/- 0.01 x 10(9)/l; 2.1 +/- 0.2%), p less than 0.01. No differences were detected between the three groups with respect to total T-lymphocytes (CD3), helper T-lymphocytes (CD4), suppressor cytotoxic T-lymphocytes (CD8), or the inducer of suppressor (Leu 3+/Leu 8+) subset of T-lymphocytes. Three women persistently islet cell antibody positive, two of whom were HLA DR4, showed impaired glucose tolerance at the time of lymphocyte subset analysis, while two further patients, one DR3 and the other DR4, had developed type 1 (insulin-dependent) diabetes. No correlation between increased Interleukin 2 receptor expression and glucose intolerance was demonstrated. We conclude that islet cell antibody positive women with impaired glucose tolerance during pregnancy are at increased risk of later developing type 1 diabetes but that heightened immune activation present in these women is in part a post-pregnancy phenomenon.

Normal suppressive T cell function of Epstein-Barr virus induced B cell activation in type 1 (insulin dependent) diabetes mellitus

Several studies have demonstrated abnormalities of T cell regulation of Epstein-Barr virus-induced B cell activation in systemic autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematous, and systemic sclerosis. However, a normal suppressive peripheral T cell function was observed in Graves' disease. To investigate whether this abnormality is a common feature to other autoimmune diseases, we studied T cell regulation of Epstein-Barr virus induced B cell activation in 15 newly diagnosed type 1 (insulin dependent) diabetes mellitus patients and 10 normal control subjects. Peripheral B lymphocytes infected with Epstein-Barr virus were cultured for 20 days in the presence or absence of autologous T cells at different ratios (1:1 and 1:4). IgM and IgG secretions into the supernatants were determined using an enzyme-linked immunosorbent assay. The extent of suppression when T cells were added, as measured by a suppression ratio, was not significantly different in type 1 (insulin dependent) diabetes mellitus patients and normal subjects. We conclude that in type 1 (insulin dependent) diabetes mellitus, the autoimmune reactivity is not dependent upon a generalized suppression defect. It can be hypothesized, therefore, that in type 1 diabetes mellitus as well as in Graves' disease, a local or organ specific suppressor deficit may induce the autoimmune phenomena.

Cluster analysis of an insulin-dependent diabetic cohort towards the definition of clinical subtypes

Clinical and biochemical data on 111 consecutive insulin-dependent diabetic children enrolled in a longitudinal prospective study were analyzed to determine if more than one clinical expression of Type I diabetes exists. Use of multivariate statistical methods, including Correspondence Analysis, kappa-means clustering and RECPAM (RECursive Partition and AMalgamation), show that there are two well differentiated clinical expressions of IDDM each characterized by a cluster. One is characterized by later age, less severe onset, longer symptom duration, less beta-cell disappearance after 12 months, more females; the other by earlier age, more sudden and severe onset, DR 3/4, earlier disappearance of beta-cell function and more males. RECPAM analysis provides further insight into the structure of the two clusters. An other RECPAM tree identifies low, medium and high risk groups of disappearance of beta-cell function at 12 months after diagnosis.

The presence of splenic T cells specific for islet cell antigens in nonobese diabetic mice

Nonobese diabetic (NOD) mice display a syndrome with dramatic clinical and pathological features similar to Type 1 diabetes in man. Mononuclear cells intensively infiltrate the pancreas (insulitis), mostly T cells taking part. However, the functional role and specificity of these cells are currently uncertain. We investigated the response of splenic T cells from NOD mice to islet cells, using interleukin 2 (IL-2) production and cell proliferation. Splenic T cells from NOD mice responded with IL-2 production and proliferation when both islet cell antigens from NOD mice and mitomycin C-treated spleen cells (source of antigen-presenting cells) from NOD mice or major histocompatibility complex (MHC)-compatible ILI mice were present. Splenic T cells could produce IL-2 in response to islet cells from sources other than the NOD mouse, but could not produce significantly this lymphokine in response to submandibular gland, gastric mucosal, liver, spleen, and ovarian cells from NOD mice. NOD T cells produced this antigen-specific response first when the mice were 8 weeks old, the response grew stronger until 20 weeks of age and then tapered off. The present study indicates the presence of T cells specific for islet cell antigens in the spleen of NOD mice and suggests that the antigen-specific T cell response increases in parallel with the development of insulitis.