Suppressor cell function and T lymphocyte subpopulations in peripheral blood of patients with progressive systemic sclerosis

Systemic sclerosis and the risk of tuberculosis

OBJECTIVE

Pulmonary involvement is common in patients with systemic sclerosis (SSc), and this condition causes substantial morbidity and mortality. Disrupted immunity from the disease or associated medication may render such patients subject to tuberculosis (TB) infection. However, the relationship between SSc and TB has not yet been investigated.

METHODS

Using the Taiwan National Health Insurance Research Database, 838 patients with SSc diagnosed in Taiwan during 2000-2006 were identified and followed for emergence of TB infection. Incidence rate ratios (IRR) of TB compared to 8380 randomly selected age-, sex-, and comorbidity-matched controls without SSc were calculated. The Cox proportional hazards model was used for multivariate adjustment to identify independent risk factors for TB infection.

RESULTS

The risk of TB infection was higher in the SSc cohort than in controls (IRR 2.81, 95% CI 1.36-5.37; p = 0.004), particularly for pulmonary TB (IRR 2.53, 95% CI 1.08-5.30; p = 0.022). Other independent risk factors for TB infection in patients with SSc were age ≥ 60 years [hazard ratio (HR) 3.52, 95% CI 1.10-11.33; p = 0.035] and pulmonary hypertension (PH; HR 6.06, 95% CI 1.59-23.17; p = 0.008). Mortality did not differ for SSc patients with or without TB.

CONCLUSION

In this nationwide study, the incidence of TB infection was significantly higher among patients with SSc than in controls without SSc. Special care should be taken in managing patients with SSc who are at high risk for TB, especially those aged ≥ 60 years or who also have PH.

Tumor necrosis factor-costimulated T lymphocytes from patients with systemic sclerosis trigger collagen production in fibroblasts

OBJECTIVE

The role of tumor necrosis factor (TNF) in systemic sclerosis (SSc) remains controversial. The present study was undertaken to investigate the influence of TNF receptor (TNFR)-costimulated lymphocytes on collagen expression in fibroblasts.

METHODS

TNFR expression on mononuclear cells from the dermis and blood of SSc patients was assessed by flow cytometry. Peripheral blood CD3+ lymphocytes were activated with CD3/CD28 beads and costimulated with TNFR-selective variants. Expression of interleukin-6 (IL-6), soluble IL-6 receptor (sIL-6R), IL-10, and IL-13 was detected by enzyme-linked immunosorbent assay or quantitative reverse transcription-polymerase chain reaction. Healthy fibroblasts were incubated with conditioned media from TNFR-costimulated T lymphocytes, and type I collagen expression was quantified.

RESULTS

TNFRI and TNFRII were up-regulated on dermal T lymphocytes from patients with diffuse cutaneous SSc. TNFRII expression correlated with skin thickening. After CD3/CD28 activation, peripheral blood lymphocytes from SSc patients produced more IL-6, sIL-6R, and IL-13 compared to healthy lymphocytes. Costimulation with TNFRI-selective ligands and soluble TNF further increased IL-6 expression, whereas costimulation with TNFRII led to greater release of sIL-6R. IL-10 expression, which normally occurs after TNFRII costimulation, was impaired in SSc T cells. Supernatants of TNF-costimulated SSc lymphocytes induced higher type I collagen expression in fibroblasts, which was partially reversible by dual inhibition of IL-6 and IL-13. Expression of TNFR and IL-6 in the dermis was reversible in a patient who received lymphoablative therapy prior to autologous hematopoietic stem cell transplantation.

CONCLUSION

TNF-costimulated T lymphocytes from SSc patients have a propensity to secrete profibrotic cytokines, while the ability to produce IL-10 is weakened. These results suggest that T lymphocytes in SSc support fibrosis, but might lack the capacity to resolve inflammation.

Response of T-cell subpopulations to superantigen and recall antigen stimulation in systemic sclerosis

Background:

There is great disagreement regarding which effector T-cells are responsible for the pathogenesis of systemic sclerosis. Further, the possible role of superantigens in modulating the T-cell phenotype responsible for the immunopathogenesis of this disease and the response of these patients to common recall antigens have not been adequately determined.

Aims:

To investigate the T-cell subsets and activation markers in peripheral blood mononuclear cells of systemic sclerosis patients before and after stimulation with different bacterial superantigens and common recall antigens to better understand the immunopathogenesis of this disease.

Materials and Methods:

T-cells (CD3⁺) from 20 systemic sclerosis patients and 17 age-matched healthy controls were studied using flow cytometry for the expression of CD4, CD8, CD45RA, and CD45RO at baseline and upon stimulation with different superantigens and recall antigens. Patients were also tested for skin delayed hypersensitivity to common recall antigens.

Results:

The proportions of CD45RA⁺ (naive) and CD45RO⁺ (memory) CD4⁺ T-cells were found to be significantly higher in patients than in controls upon stimulation with bacterial superantigens. However, T-cells from these patients responded weakly to recall antigen stimulation, indicating a loss of specific memory cells. This was further supported by the skin delayed hypersensitivity test in which 16 patients were found to be anergic.

Conclusions:

Our findings suggest that both naïve (CD45RA⁺) and memory (CD45RO⁺) CD4⁺ superantigen-reactive T-cells are effector T-cells that may modulate the pathogenic autoantibody response in systemic sclerosis. Accumulation of these cells in these patients may result in increased risk of relapses and resistance to therapy.

CD8+ T-Cell Deficiency, Epstein-Barr Virus Infection, Vitamin D Deficiency, and Steps to Autoimmunity: A Unifying Hypothesis

CD8+ T-cell deficiency is a feature of many chronic autoimmune diseases, including multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus, Sjögren's syndrome, systemic sclerosis, dermatomyositis, primary biliary cirrhosis, primary sclerosing cholangitis, ulcerative colitis, Crohn's disease, psoriasis, vitiligo, bullous pemphigoid, alopecia areata, idiopathic dilated cardiomyopathy, type 1 diabetes mellitus, Graves' disease, Hashimoto's thyroiditis, myasthenia gravis, IgA nephropathy, membranous nephropathy, and pernicious anaemia. It also occurs in healthy blood relatives of patients with autoimmune diseases, suggesting it is genetically determined. Here it is proposed that this CD8+ T-cell deficiency underlies the development of chronic autoimmune diseases by impairing CD8+ T-cell control of Epstein-Barr virus (EBV) infection, with the result that EBV-infected autoreactive B cells accumulate in the target organ where they produce pathogenic autoantibodies and provide costimulatory survival signals to autoreactive T cells which would otherwise die in the target organ by activation-induced apoptosis. Autoimmunity is postulated to evolve in the following steps: (1) CD8+ T-cell deficiency, (2) primary EBV infection, (3) decreased CD8+ T-cell control of EBV, (4) increased EBV load and increased anti-EBV antibodies, (5) EBV infection in the target organ, (6) clonal expansion of EBV-infected autoreactive B cells in the target organ, (7) infiltration of autoreactive T cells into the target organ, and (8) development of ectopic lymphoid follicles in the target organ. It is also proposed that deprivation of sunlight and vitamin D at higher latitudes facilitates the development of autoimmune diseases by aggravating the CD8+ T-cell deficiency and thereby further impairing control of EBV. The hypothesis makes predictions which can be tested, including the prevention and successful treatment of chronic autoimmune diseases by controlling EBV infection.

Increased CD8+ T cell apoptosis in scleroderma is associated with low levels of NF-kappa B

Our objectives were (1) to compare lymphocyte subpopulation apoptosis rates in SSc patients versus healthy controls and (2) to compare Bcl-2 and NF-kappa B expression in cultured CD8 lymphocytes of SSc patients versus controls. Peripheral blood samples were obtained from 27 SSc patients meeting the American College of Rheumatology criteria for SSc and 28 healthy individuals. Mononuclear cells were isolated by Ficoll-Hypaque density gradient separation and cultured for 48 hr. For determination of apoptosis within specific cell populations, samples were labeled with PE-conjugated monoclonal antibody to CD8, CD4, and a FITC-conjugated monoclonal antibody to Annexin V. Flow cytometry was carried out with a FACS operating with Cellquest software. CD8+ lymphocytes were positively selected with magnetic microbeads conjugated to antihuman CD8. CD8 T cells were separated, then incubated with activation for 48 hr, and NF-kappa B and Bcl-2 analysis was carried out using Western immunoblotting. The CD4:CD8 ratio was increased in SSc compared to controls (2.6 +/- 1.13 vs.1.87 +/- 0.76; P = 0.018). The spontaneous apoptosis rate of SSc CD8 lymphocytes was increased compared to that of controls of (21.9 +/- 13.7 vs. 13.3 +/- 9.9; P = 0.019). No difference was found in the rate of CD4 apoptosis of SSc patients versus controls (9.8 +/- 5.2 vs. 7.18 +/- 4.89%; P = ns). The expression of NF-kappa B in SSc CD8 lymphocytes was decreased compared with that of CD8 lymphocytes from healthy controls (144 +/- 13 vs. 188 +/- 11; P = 0.018). Whereas expression of Bcl-2 was similar in activated CD8+ T cells of SSc patients and healthy controls, CD8+ T cell apoptosis rate was found to be in reverse correlation with expression of NF-kappa B in these cells ( r = - 0.53, P = 0.029). The increased CD4:CD8 ratio in SSC may result from increased CD8+ T cell apoptosis. Increased SSc CD8 T cell apoptosis is associated with low levels of NF-kappa B.

Fatal exacerbation of paraneoplastic systemic sclerosis after neoadjuvant chemotherapy in a breast cancer patient

Paraneoplastic systemic sclerosis (SSc) occurs in about 3%-7% of individuals with SSc. There are reports of accelerated SSc syndromes associated in particular with breast cancer. Further exacerbations of the rheumatic condition may be induced by treatment of the cancer. We report a 30-year-old African-American woman with a contiguous diagnosis of breast cancer and paraneoplastic SSc. She was treated with neoadjuvant chemotherapy and developed an accelerated SSc syndrome with pericarditis and cardiac tamponade, with lethal results. This case report stresses the need for control of the rheumatic condition prior to the initiation of antineoplastic therapy.

The Th1/Th2 paradigm in the pathogenesis of scleroderma, and its modulation by thalidomide

The immunity generated in response to an antigenic stimulus can result in at least two distinct subclasses of immune responses, commonly referred to as Th1 and Th2. This review describes Th1- and Th2-type immune responses in animal models and in human mediated disease. Evidence obtained from working within these models suggests that manipulating the Th1/Th2 balance in the immune response can alter disease processes. The possible application of this strategy in scleroderma is presented. The immune modulating effects of the drug thalidomide on Th1 and Th2 immunity are also described, along with the drug's potential application to disease processes like scleroderma.

Role of T cells and cytokines in effecting fibrosis

A number of humoral and cellular immune abnormalities are present in patients with early scleroderma (systemic sclerosis). Most of these abnormalities reflect ongoing autoimmune reactions of the cellular and humoral types, resulting in a variety of autoantibodies to cellular and tissue constituents. Evidence exists for a defect(s) in immunoregulation favoring excessive helper T cell activity. The presence of circulating cytokines and shed interleukin-2 receptors suggest ongoing cellular immune reactions are occurring, generating cytokines and lymphokines that are capable of effecting the vascular and fibrotic lesions that are hallmarks of the disease. Future directions for research are suggested that would focus on determining if, and at what point, fibroblasts might function autonomously to generate excessive matrix components and on determining the nature of the original antigenic stimulus that starts the scleroderma process.

CD4+ and CD8+ subsets: naive and memory cells in the peripheral blood of patients with systemic sclerosis

Systemic Sclerosis (SSc; scleroderma) is associated with several immunological abnormalities, including altered proportion between lymphocyte subsets. Peripheral blood lymphocyte subsets from 25 patients with SSc were studied by two-colour flow cytometry using monoclonal antibodies against CD45RA and CD29 markers, which allow a dissection of CD4+ and CD8+ populations into 'naive' and 'memory' subsets. A decrease of the percentage of CD8+ (p < 0.05) and of CD8+CD29+ (p < 0.001) cells was observed compared to that in 20 age and sex-matched controls. These abnormalities were not significantly associated with the extension of cutaneous disease or other clinical features of SSc nor with treatment, pattern of autoantibodies or HLA phenotype.

Immunologic parameters in systemic sclerosis

BACKGROUND

Immunologic abnormalities seem to play an important role in important role in systemic sclerosis (SSc).

METHODS

We studied the following immune parameters to get more insight into SSc: autoantibodies (antinuclear antibodies (ANA), anti-Scl-70, anticentromere antibodies (ACA) subsets of lymphocyte subpopulations and markers of their activation, as well as serum levels of IL-2, the soluble IL-2 receptor (SIL-2R), IL-6 and its correlation to N-terminal procollagen-III propeptide (P III P), and finally, the IL-6 production by SSc and normal dermal fibroblasts.

RESULTS

In patients with active SSc, we found a reduced number of CD2+ T-lymphocytes and an increase in the expression of T-lymphocyte activation markers such as CD25+ and CD71+, HLA-DR Ia, as well as elevated serum levels of SIL-2LR and IL-6. SSc fibroblasts did not produce more IL-6 than normal fibroblasts in monolayer cultures.

CONCLUSIONS

Our data show that a wide range of immunologic parameters are altered in SSc. In general, T-helper (TH) lymphocytes are activated possibly because of reduced T-suppressor (TS) and natural killer (NK)-cell levels. TH may polyclonally stimulate B cells, which in turn produce higher amounts of autoantibodies. Our findings support the concept that TH cell-derived cytokines/growth factors stimulate matrix protein synthesis by fibroblasts, resulting in generalized fibrosis.

Interstitial lung disease and myositis in a patient with simultaneously occurring sarcoidosis and scleroderma

A patient initially presented with sarcoidosis in combination with myositis of sarcoid origin and Raynaud's phenomenon. During the course of his disease, he additionally developed scleroderma. Bronchoalveolar lavage, performed because of increase of interstitial markings in the presence of enlarged hilar nodes, showed an increased percentage of granulocytes and a low CD4 to CD8 ratio of lymphocytes, suggesting a change to scleroderma lung disease.

Analysis of lymphocyte subpopulations in peripheral blood in adult and juvenile cases of dermatomyositis

Dermatomyositis, recognized as an autoimmune disorder, occurs not only in adults but also in children. In this study, we evaluated lymphocyte subpopulations in the peripheral blood of 24 adult dermatomyositis and 14 juvenile dermatomyositis patients and in 17 healthy adults and 9 healthy children by flow cytometry using monoclonal antibodies. When compared with healthy adults and adult patients with inactive dermatomyositis, the adult patients with active disease had significantly lower percentages of CD3+ and CD8+ cells and a significantly higher percentage of CD20+ cells. In contrast, juvenile dermatomyositis patients had lymphocyte subpopulations not significantly different from those of healthy children; the activity/inactivity of disease did not make any difference. These results support our hypothesis that adult and juvenile dermatomyositis may be diseases of entirely different scope.

Abnormalities of T lymphocyte subsets in systemic sclerosis demonstrated with anti-CD45RA and anti-CD29 monoclonal antibodies

T cell subpopulations were assessed by two colour flow cytometry with phycoerythrin conjugated anti-CD45RA and anti-CD29 and fluorescein conjugated anti-CD4 and anti-CD8 monoclonal antibodies, on peripheral blood lymphocytes from 12 patients with systemic sclerosis and from nine control subjects. The percentage of CD4+CD29+ cells was significantly higher in patients with systemic sclerosis than in controls (mean (SEM) 68.8 (3.1) v 47.9 (4.1) respectively). CD4+CD45RA+ cells were not significantly different in patients and controls. CD8+CD29+ and CD8+CD45RA+ subpopulations were significantly higher in patients with systemic sclerosis than in controls (83.0 (3.2) v 58.7 (6.8) and 80.2 (3.0) v 66.9 (3.2) respectively). The increase in the percentage of CD29+ cells suggests an activation of memory cells in patients with systemic sclerosis, which may play an important part in the pathogenesis of the disease.

Altered T cell subpopulations and lymphocytes expressing natural killer cell phenotypes in patients with progressive systemic sclerosis

Scleroderma (progressive systemic sclerosis [PSS]) is known to be associated with abnormal T cell immunoregulation. In the present study, we evaluated lymphocyte phenotypes in patients with PSS and normal control subjects by flow cytometry and monoclonal antibodies for total T (CD3), T suppressor (CD8), T helper (CD4), T helper-inducer (CDw29), T suppressor-inducer (CD45R), human leukocyte antigen, DR+B (CD19), DR+T, and natural killer subsets, HNK-1 (CD57) and NKH-1 (CD56) cells. Patients with PSS compared to normal subjects had significantly lower percentages of CD3+ (p less than 0.005) and CD8+ (p less than 0.05) (similar to several patients with rheumatoid arthritis also evaluated), as well as CD45R (p less than 0.05), T+DR+ (p less than 0.05), and NKH-1 (CD56) (p less than 0.0005) cells. Patients with PSS with late-limited or generalized disease had lower percentages of CD8+, CD19, NKH-1+, and CDw29, but higher percentages of CD4+, HNK-1, and CD45R cells compared to patients with early stage disease, but these results were not statistically significant. These unique alterations in patients with PSS may prove to be useful in monitoring the stage of disease activity for therapy and further define immunologic defects.

Soluble and cellular markers of immune activation in patients with systemic sclerosis

The peripheral blood lymphocyte pattern, the lymphocyte responses in vitro, as well as the soluble markers of immune activation were studied in 24 patients with systemic sclerosis (SSc patients). The proportions of total T cells (CD3), their CD4 subset, as well as B lymphocytes were within the normal range. The relative proportion of CD8 lymphocytes, however, was significantly reduced. Patients with SSc had a slightly lower percentage of CD4/4B4+ cells, whereas their proportion of CD4/2H4+ cells was elevated as compared to healthy controls. The proportion of lymphocytes expressing the interleukin-2 receptor (IL-2R) was significantly higher in SSc patients. The proliferative responses of peripheral blood mononuclear cells to PHA stimulation were reduced in the patient group, while expression of IL-2R on lymphocytes after such in vitro stimulation was comparable to that of controls. Expression of IL-2R on patient but not control lymphocytes was increased after in vitro exposure to laminin. Such exposure failed to induce IL-2 production or cell proliferative responses. Soluble plasma IL-2R level (sIL-2R) and soluble CD8 (sCD8) molecule levels in SSc patients were significantly elevated. These results indicate the presence of an ongoing lymphocyte activation in this disease process.

Natural killer activity and antibody-dependent cellular cytotoxicity in progressive systemic sclerosis

Enhanced natural killer (NK) activity and normal lymphocyte antibody-dependent cellular cytotoxicity (ADCC) were observed in 16 patients with a diagnosis of progressive systemic sclerosis (PSS). Higher NK activity levels were observed against NK-sensitive K562 target cells, while the NK-resistant P815, Daudi and Raji cell lines were not lysed. Cytofluorimetric studies and morphological analysis of peripheral blood lymphocytes (PBL) showed an increased number of CD16 positive cells and large granular lymphocytes (LGL), indicating that the enhancement observed was probably attributable to an increase in the number of circulating NK cells.

Cyclosporin A treatment of systemic sclerosis

Ten patients with severe progressive systemic sclerosis were treated with cyclosporin A at dosages of 1.5-7.5 mg/kg per day:two patients showed a marked improvement with softening of the involved skin; in one patient there was healing of persistent digital ulcers; one patient showed initial improvement followed by a marked exacerbation; one patient was slightly improved; two patients were unchanged. The clinical results correlated well with levels of serum aminoterminal propeptide of type III procollagen. In the eight patients completing treatment, side-effects such as slight tremor and a transient increase in the serum creatinine and blood pressure were either absent or reverted to normal when the dosage was decreased, except one case who had to be treated with anti-hypertensive drugs.

Soluble interleukin-2 receptors in patients with systemic sclerosis. Clinical and laboratory correlations

Plasma levels of soluble interleukin-2 receptors (sIL-2R) were measured by an enzyme-linked immunosorbent assay in 79 patients with systemic sclerosis (SSc). These levels were significantly elevated in SSc patients, compared with normal controls (mean +/- SEM 866.0 +/- 63.6 units/ml versus 293.0 +/- 20.5; P less than 0.001). Soluble IL-2R levels were highest in patients with generalized disease, were strongly associated with mortality (P less than 0.001) and inversely correlated with disease duration (P = 0.003), but were not related to sex, age, specific visceral involvement, serologic status, peripheral lymphocyte count, or therapy. Levels of sIL-2R in the supernatants of peripheral blood mononuclear cells were low in patients and controls, and showed comparable increases following phytohemagglutinin stimulation. Exposure of peripheral blood mononuclear cells to laminin did not induce sIL-2R release. Circulating IL-2 levels were comparably low in patients and controls. Our findings suggest the presence of lymphocyte activation in SSc, and further suggest that measurement of sIL-2R may prove to be a useful laboratory technique for assessing disease activity.

Recombinant interferon-gamma in the treatment of systemic sclerosis

PURPOSE

Recombinant interferon-gamma (IFN-gamma) is a potent and selective inhibitor of collagen production by dermal fibroblasts in vitro and has numerous immunoregulatory activities. We assessed the effects of recombinant IFN-gamma in the treatment of patients with systemic sclerosis.

PATIENTS AND METHODS

Ten patients entered the study and nine completed the six-month study period. Recombinant IFN-gamma was administered once daily for seven days per week by intramuscular injections: 10 micrograms/day for 10 days, 25 micrograms/day for 10 days, 50 micrograms/day for 10 days, and 100 micrograms/day for the next five months.

RESULTS

After the six-month treatment period, a significant improvement, as compared with base-line values, was observed in total skin score, maximal oral opening, range of motion of wrists and elbows, grip strength, functional index, dysphagia, and creatinine clearance. No serious side effects were observed; however, a significant decrease in white blood cell counts and in peripheral blood lymphocytes was noted.

CONCLUSION

These results suggest that recombinant IFN-gamma may be beneficial in the treatment of patients with systemic sclerosis.

Immunosuppression with chlorambucil, versus placebo, for scleroderma. Results of a three-year, parallel, randomized, double-blind study

Placebo and chlorambucil (0.05-0.1 mg/kg/day) were compared as treatments for scleroderma in a 3-year, randomized, double-blind, parallel study of 65 patients. Slopes of change over time, calculated for each organ system of each patient, failed to show significant differences between treatment groups. An immunosuppressive effect in the chlorambucil-treated group was shown by decreases in the white blood cell counts (P = 0.02), platelet counts (P = 0.04), lymphocyte counts (P = 0.001), IgA/IgM concentrations (P less than or equal to 0.05), and wheal size on mumps skin tests (P = 0.02). Three years of immunosuppressive treatment with chlorambucil did not benefit this scleroderma population.

Increased proto-oncogene expression in peripheral blood T lymphocytes from patients with systemic sclerosis

The expression of c-myc, c-myb, and c-ras proto-oncogenes, determined using RNA hybridization techniques (slot-blot), was significantly increased in peripheral blood T lymphocytes, but not in B cells, from 17 patients with systemic sclerosis with diffuse scleroderma, compared with the expression in normal control subjects. The magnitude of expression of c-myc and c-myb tended to be higher in patients with early, active disease. These results demonstrate an in vivo activation of T cells from systemic sclerosis patients, which may play an important role in the pathogenesis of the disease.

Lymphocyte proliferative response to mitogenic monoclonal antibodies in systemic sclerosis. Evidence for unresponsiveness to murine monoclonal antibodies of IgG1 isotype

Proliferative response of peripheral blood mononuclear cells to phitohemoagglutinin and anti-CD3 mitogenic monoclonal antibodies (MoAbs) of the IgG2a (OKT3) and IgG1 (PanT2, CLB T3/4.1) isotypes was studied in 39 patients with systemic sclerosis (SSc) and in 82 control subjects. The effect of IL-2 on this response was also investigated. No difference in the response to PHA and to IgG2a anti-CD3 MoAb OKT3 was seen between scleroderma patients and controls. Both the patient and control groups contained responders and non-responders to IgG1 anti-CD3 MoAbs. The percentage of non-responders was significantly higher in scleroderma patients than in controls. When purified lymphocytes from non-responder scleroderma patients were cultured with monocytes from control responders, proliferative response to IgG1 MoAbs was restored. Our results show that monocytes from patients with systemic sclerosis bear a defect leading to IgG1 unresponsiveness by T lymphocytes.

Reduced natural killer cell activity in patients with systemic sclerosis. Correlation with clinical disease type

Natural killer (NK) cell number and function were determined in 69 systemic sclerosis (SSc) patients (41 with diffuse cutaneous SSc, 24 with limited cutaneous SSc, and 4 with scleroderma in an overlap syndrome). The results were compared with those obtained from 5 patients with Raynaud's disease and from 27 normal controls. Natural and antibody-dependent killing was reduced in the total group of SSc patients compared with controls, but these differences were primarily attributable to patients with the diffuse form of the disease who were seen early in their illness (less than 5 years after onset). NK cell numbers were not significantly reduced in patients compared with controls, although lower numbers were observed in individuals with early diffuse disease. Other clinical parameters, such as treatment with D-penicillamine or the presence of scleroderma-specific autoantibodies, did not exert an independent effect on NK cell function. These findings suggest a possible central role for NK cells in the pathogenesis of SSc.

Theophylline-resistant and theophylline-sensitive "active" and "total" E rosette-forming lymphocytes in patients with systemic scleroderma

Using the E rosette test and its modification with theophylline, we have studied T regulatory lymphocytes in various forms of systemic scleroderma. Mean percentages of active rosette-forming cells (ARFC) as well as the fraction resistant to theophylline incubation (ARFC-res) were significantly decreased, irrespective of the variety of the disease, compared to the age-matched controls. Late ("cold") rosette-forming fractions were unimpaired. The theophylline-sensitive fraction of total rosette-forming cells (TRFC-sens), which contains mainly cells from the suppressor circuit, was found to be lowered in all patients groups studied, whereas the ARFC-sens fraction was significantly decreased only in patients with diffuse scleroderma over 50 years of age, in whom there was a tendency to a more severe course, as manifested by pronounced systemic organ involvement. The lowered values of E rosette tests were found in a majority of SSc patients and were correlated with the appearance in the sera of factors capable of inhibiting ARFC formation by normal human peripheral blood T lymphocytes. Normal values of the E rosette test were related to the presence in the patients' sera of factors stimulating ARFC formation by normal lymphocytes. We surmise from the results that in SSc patients the T-cell defect is not only restricted to T suppressor cells but also refers to the active theophylline-resistant fraction containing mainly T inducer and T cytotoxic cells.

Systemic scleroderma. Clinical and pathophysiologic aspects

Systemic scleroderma is a generalized disease of connective tissue involving mainly the skin, the gastrointestinal tract, the lungs, the heart, and the kidneys. It can be present in different forms, of which acroscleroderma, with limited cutaneous and extracutaneous involvement, and diffuse scleroderma within a more rapid progression are most characteristic. Circulating antibodies against antinucleolar antigens are present in most patients with systemic scleroderma. They are helpful for establishing a classification and for determining the prognosis of the disease; their involvement in the pathogenesis, however, is still unclear. Alterations of the blood vessels and induction of fibroblasts by potent mediators are thought to play an important role in the early phase of scleroderma. Therefore early diagnosis is required, which then can initiate vasoactive therapy. In patients with systemic scleroderma, who also suffer from additional myositis, interstitial lung diseases, or arthritis, anti-inflammatory treatment with prednisolone and azathioprine is suggested. Development and progression of fibrosis cannot yet be influenced sufficiently. Only D-penicillamine affecting cross-linking of collagen has been widely used in scleroderma and has some beneficial effect.

Enhanced production of interleukin-2 in patients with progressive systemic sclerosis. Hyperactivity of CD4-positive T cells?

A significant enhancement of interleukin-2 production was observed in phytohemagglutinin-stimulated peripheral lymphocytes from patients with progressive systemic sclerosis (PSS). Their Leu-3a:Leu-2a ratio was also significantly higher than normal. Moreover, Leu-3a+ cells freshly purified from PSS patients' blood produced much more interleukin-2 than did cells from normal subjects. These results suggest that T cell hyperactivity, especially among Leu-3a+ T cells, occurs in patients with PSS.

Malignant thymoma associated with progressive systemic sclerosis

A 65-year-old man manifested certain features of scleroderma several years before discovery of malignant thymoma. Following tumor resection, the signs and symptoms of scleroderma did not improve, and the patient experienced the abrupt onset of renal failure with malignant hypertension 7 months after the operation. The scleroderma renal crisis caused terminal renal failure, which was treated by chronic hemodialysis. This is the second reported case of thymoma associated with progressive systemic sclerosis (PSS). The authors suggest that thymoma and various immunologic disorders have a common etiologic factor which has not yet been found. This case emphasizes that thymectomy frequently has little effect on the course of the immunologic disease. The implications of the association of thymoma and PSS are discussed.

Abnormal lymphocyte function in scleroderma: a study on identical twins

This paper describes immunologic studies on a set of identical twins discordant for the presence of scleroderma. The affected twin had a low absolute T-cell count, low numbers of T4 helper/inducer cells, and an increase in the T8 suppressor/cytotoxic cell count. The T cells of the patient responded poorly to mitogens and to allogeneic and autologous stimuli. By contrast, T-cell-helper activity for pokeweed mitogen-induced IgM synthesis was markedly enhanced in the patient. Furthermore, activated mononuclear cell supernatants from the patient markedly enhanced the synthesis of collagen by normal cultured fibroblasts. The unaffected twin by contrast displayed normal responses in these assays. The results suggest that the immunologic defects in scleroderma are not entirely genetically determined.

Progressive systemic sclerosis occurring in patients exposed to chemicals

Eight patients with systemic sclerosis previously exposed to organic chemical agents were investigated. Laboratory and clinical data of these patients were evaluated. The interval between the beginning of exposition and symptoms was 6.1 +/- 4.9 years. Considering the laboratory findings, a slight decrease in OKT4 positive T cell number was found. The antinucleolar and fine speckled antinuclear antibody pattern was found simultaneously in five cases. The possible role of chemical agents in the development of sclerodermic changes is discussed.

Natural killer cell activity of peripheral blood mononuclear cells from patients with various forms of systemic scleroderma

Peripheral blood mononuclear cells from 63 patients with systemic scleroderma, including incipient or prodromal acrosclerosis, and from 20 healthy individuals were tested for natural killer (NK) cell activity and antibody-dependent cell cytotoxicity in a 4 h 51Cr release assay using K562 and L1210 cell lines respectively. In patients with systemic scleroderma natural killer cell activity was significantly decreased compared with the controls. NK cell activity was markedly lowered in patients with diffuse scleroderma and in transitional form acrosclerosis-diffuse scleroderma, and was normal in cases of acrosclerosis and/or CREST syndrome and in cases of prodromal or incipient scleroderma. Antibody-dependent cell cytotoxicity of mononuclear cells from the systemic scleroderma patients was within the normal range. The lowered natural killer cell activity correlated with the severity of systemic scleroderma, in terms of the extent of skin and organ involvement.

Defective Epstein-Barr virus specific suppressor T cell function in progressive systemic sclerosis

Several immunoregulatory defects of Epstein-Barr virus (EBV) induced B cell activation have been described in patients with rheumatoid arthritis (RA), suggesting that EBV may have a role in the pathogenesis of RA. We assessed EBV specific T cell regulation in 20 patients with progressive systemic sclerosis (PSS) and immune to EBV and in 10 control subjects also immune to EBV by comparing the secretion of IgM into supernatants of 16 day cultures of B cells alone and cocultures of B and autologous T cells. In control subjects autologous T cells mediated a significant decrease in the secretion of IgM by B cells at 12 and 16 days of culture. Analysis of individual responses showed the existence of two subgroups of patients with PSS: group I (10 patients) had a suppressor T cell function similar to that of controls; group II (10 patients) had a defective T cell function. Differences in the duration or severity of the disease, the slow acting therapeutic agents, and anti-inflammatory drugs could not account for these subdivisions. These results suggest that several immunoregulatory defects of EBV induced B cell activation exist in different connective tissue diseases.

The cardiovascular manifestations of systemic sclerosis (scleroderma)

In conclusion, systemic sclerosis is both a fascinating and frustrating affliction. It is a systemic disease of multiple stages. Prognosis is dependent on the site and extent of visceral involvement. There is evidence to implicate the vascular system as the primary target organ of the disease. The cardiovascular manifestations include myocardial fibrosis, pericarditis, and a variety of arrhythmias and conduction abnormalities. Intractable heart failure or sudden cardiac death can ensue. Cardiac involvement in systemic sclerosis portends an ominous prognosis, and is probably most directly related to the extent of myocardial fibrosis which is present. The pathogenesis of myocardial fibrosis has not been determined, but it appears to be a result of an impairment of myocardial perfusion at both the small artery and microvasculature level. Obstructive, vasospastic, and devascularization factors all may be playing a role.

Cell-mediated immunity in rheumatic disease

Rheumatoid arthritis, systemic lupus erythematosus, and systemic sclerosis are the three most common systemic rheumatic diseases in which disordered immune function is thought to play a pathogenetic role. Each disease has different and characteristic abnormalities of the cellular immune system. In rheumatoid arthritis the identified abnormalities of immunoregulation are largely limited to specific antigens: Epstein-Barr virus and collagen. Systemic lupus erythematosus is characterized by exuberant B-cell activity with exaggerated humoral response, a diversity of autoantibodies, non-antigen-specific loss of suppressor cell function, and general suppression of cell-mediated immunity. In systemic sclerosis systemic defects of cellular and humoral immune function are mild, but the release of lymphokines and monokines at sites of inflammatory lesions is thought to be important in the pathogenesis of the disease. Similar immune cell-connetive tissue cell interactions are probably important in the propagation of rheumatoid synovitis. Thus, despite the many shared clinical and serologic features of these diseases as well as the presence of many patients who have clinically overlapping features of more than one of these entities, the immune defects and the immunopathogenesis of these disorders appear to be distinct.

Anti-nuclear RNP antibodies in two sisters

Two sisters with clinical elements of mixed connective tissue disease were found to have anti-nuclear RNP (nRNP) antibodies. These antibodies were not found in the six other family members examined. The sisters had inherited an identical HLA haplotype A2-Bw61-Cw3-DR1 from their mother who had had Raynaud's phenomenon for several years. Analysis of peripheral lymphocyte subsets in the patients and their immediate relatives showed decreased OKT-4-positive cells in one of the patients and increased OKT-8-positive cells in both patients, their father and their brother, resulting in lower OKT 4/OKT 8 ratios in these members of the family. This is the third description of the familial occurrence of anti-nRNP antibodies and it adds further evidence for the implication of genetic factors in the development of anti-nRNP antibodies.

A general strategy for the use of allogeneic lymphocyte infusions in the treatment of disorders characterized by impaired helper or suppressor T cell function: autoimmune diseases and the acquired immunodeficiency syndrome (AIDS)

Allogeneic lymphocytes can exert very potent non-specific immunomodulatory effects both in vitro and in vivo. Repeated infusions of allogeneic suppressor or helper populations may find use in the treatment of diseases characterized by impaired suppressor function (such as many autoimmune diseases) or impaired helper function (such as AIDS), respectively. Nutritional adjuvants for use with allogeneic suppressor therapy may include essential fatty acids, zinc, selenium, and vitamin E; the latter two nutrients as well as vitamin C and beta carotene may have value as adjuvants for allogeneic helper therapy. In a small preliminary trial, long-lasting normalization of rheumatoid factor titers and clinical symptoms has been achieved in 5 of 7 cases of chronic rheumatoid arthritis treated with allogeneic lymphocyte infusions, selenium, and vitamin E. These results indicate that allogeneic lymphocyte infusions accompanied by antioxidant support can promote the induction of new appropriate suppressor activity in the host. This phenomenon of allogeneic suppressor induction may be more clinically important than direct allosuppression of host B cells under the conditions of this study, and may find application in the treatment of a number of autoimmune disorders.

Lymphokine/monokine inhibition of fibroblast proliferation and collagen production: role in progressive systemic sclerosis (PSS)

A normal fibrotic response to inflammatory stimuli appears to be dependent on the balanced production of a number of stimulatory and inhibitory fibroblast-regulatory mediators by activated mononuclear cells (MNL). To investigate whether altered mediator production contributes to the fibrosis observed in progressive systemic sclerosis (PSS), we stimulated human peripheral blood MNL with concanavalin A (Con A) and lipopolysaccharide (LPS) to produce macromolecular mediators that inhibit the proliferation and the collagen production of cultured normal human fibroblasts. The two Con A-induced mediators were lymphokines (LK) as they were exclusively produced by activated T cells and they coeluted from a Sephacryl S-200 column with a Mr of 50,000. In contrast, the two LPS-induced mediators were monokines (MK) as they were exclusively produced by activated monocytes, and they coeluted in the Mr 20,000 range. Each pair of inhibitory LK and MK may also be distinct as inhibition of collagen production still occurred in proliferatively quiescent cultures. A quantitative comparison of the levels of fibroblast-inhibitory LK/MK produced by normal volunteers and long-term PSS patients revealed that although PSS MNL produced normal levels of both collagen production inhibitory mediators, they were aberrant producers of both proliferation inhibitory mediators, being hypo-producers (-49%) of the LK and hyper-producers (+196%) of the MK. These results suggest that reduced production of proliferation inhibitory LK may allow stimulatory mediators to induce the unrestricted fibroblast proliferation observed in early active PSS, which then may be stabilized in long-term PSS by the increased production of proliferation inhibitory MK.

Lymphocytes in the skin of patients with progressive systemic sclerosis. Quantification, subtyping, and clinical correlations

Mononuclear cells (MNC) present in the dermis of the forearm and in the blood of patients with progressive systemic sclerosis (PSS) were quantified and analyzed for subsets using monoclonal antibodies. The findings were correlated with cutaneous and systemic features of the disease. Total T lymphocytes and their subsets, B cells, and macrophages were enumerated in the skin samples of 21 patients with PSS. The dermal MNC infiltrates consisted mostly of activated T lymphocytes with a mean T helper/T suppressor (T4/T8) ratio of 2.4 +/- 1.3 SD. Few B1-positive or T6-positive cells (macrophages) were observed. There was no correlation between the skin or blood T4/T8 ratios and the degree of skin thickening. On histologic examination, 58 of 115 (50%) untreated patients with PSS had prominent dermal MNC infiltration. Significant correlations between the degree of MNC infiltration and both the degree (P less than 0.05) and progression (P less than 0.05) of skin thickening were observed. No correlations with other systemic disease features of PSS were noted. These results suggest that cutaneous T lymphocytes may play a role in mediating dermal sclerosis in PSS.