Gilles Feutren

CYCLOSPORIN INCREASES THE RATE AND LENGTH OF REMISSIONS IN INSULIN-DEPENDENT DIABETES OF RECENT ONSET: Results of a Multicentre Double-blind Trial

In a double-blind trial 122 patients aged 15-40 years with insulin-dependent diabetes of recent onset were randomly assigned to cyclosporin 7.5 mg/kg per day or placebo. At the sixth month 25.4% of the cyclosporin group and 18.6% of the placebo group were in complete remission (not a significant difference). Treatment was continued in those patients with complete or partial remission (insulin requirement less than 0.25 U/kg per day) and 106 patients were followed to nine months, at which stage 24.1% of the original cyclosporin group and 5.8% of the original placebo group were in complete remission (p less than 0.01). For those patients whose whole-blood trough cyclosporin levels in the first three months averaged 300 ng/ml or more, the rates of complete remission at six and nine months were 37.5% and 37%. The rates of partial remission were also higher in the cyclosporin group and at six months the rate of complete or partial remission was 46% in the whole cyclosporin group and 65.6% in those with an average blood level exceeding 300 ng/ml in the first three months, versus 28.8% in the placebo group. The principal side-effect of cyclosporin was a modest and reversible increase in plasma creatinine. These results indicate that cyclosporin promotes the remission of type I diabetes and suggest the need for new controlled protocols aimed at evaluating the length of the effect and selecting the best drug regimen.

The optimal use of cyclosporin A in autoimmune diseases

The optimal use of cyclosporin (CsA) in autoimmune diseases aims at achieving the best risk/benefit ratio and ensuring the absence of potentially irreversible adverse effects, particularly with respect to the kidney [corrected]. The experience gained with CsA therapy in more than 3,000 patients with autoimmune diseases is the basis for the current recommendations: the initial dose should be the lowest effective one and not exceed 5 mg/kg/day in non-life-threatening conditions; treatment should be as brief as possible (2-4 months) in cases of inefficacy; once a satisfactory clinical improvement has been achieved, the treatment should be maintained in the long-term using the lowest individually titrated effective dose; the dose of CsA should be decreased when serum creatinine rises by more than 30% above pre-CsA level. Continuous clinical and biological monitoring (especially of blood pressure and serum creatinine) is mandatory as long as CsA is prescribed. When these conditions are fulfilled, CsA may be an effective and safe therapy for selected autoimmune diseases, even in long-term treatment.

Plasma C-peptide levels and clinical remissions in recent-onset type I diabetic patients treated with cyclosporin A and insulin.

Remission from insulin dependency in insulin-treated recent-onset type I (insulin-dependent) diabetic patients can result from a partial recovery of insulin secretion, an improvement in tissue sensitivity to insulin, or both. The same hypothesis must be analyzed when remission occurs in cyclosporin A (CsA)-treated patients. In this study, plasma C-peptide levels were serially measured in the basal state and after stimulation in 219 recent-onset type I diabetic patients; 129 received CsA, and all patients were similarly monitored and insulin treated. The results were analyzed in view of the occurrence of remission. Remission was defined as good metabolic control in the absence of hypoglycemic treatment for ≥1 mo. Remission occurred in 44% of the CsA-treated group and lasted for mean ± SE 10.0 ± 0.9 mo vs. 21.6% in the non-CsA-treated group with a duration of 4.4 ± 0.8 mo. Plasma C-peptide levels were initially dramatically lower than normal in both groups in the basal and stimulated states. C-peptide levels increased significantly later, at 3 and 6 mo, in both groups. C-peptide values were proportional to the rates of remission in both groups. In the non-CsA-treated group, C-peptide levels later decreased, and these patients inexorably relapsed to insulin dependency. In contrast, in the CsA-treated group, the initial recovery in insulin secretory capacity was maintained over the 18–24 mo of the study. Furthermore, higher remission rates and longer-lasting remission were obtained in patients who reached higher C-peptide levels at the 3rd mo of treatment. Conversely, a progressive decrease in C-peptide values followed interuption of CsA treatment in some patients who had previously maintained some C-peptide secretory capacity. Our results support the hypothesis of an efficient suspension by CsA of the progressive deterioration of islets. The maintenance of β-cell secretory capacity by CsA plus insulin was better than by insulin alone. However, C-peptide concentrations remained lower than normal in patients in remission. An improvement in sensitivity to insulin may have also contributed to the development of remission.

Immune lysis of hepatocytes in culture: accurate detection by aspartate aminotransferase release measurement

Determination of the immune lysis of epithelial cells, especially of hepatocytes, in short term culture is dealt with inadequately because of the lack of accuracy inherent in most classical methods of measurement of cell lysis or because of the high spontaneous release of the lytic marker. We have studied different methods of detection of lysis of rat hepatocytes cultured for a short term (24-48 h) at a concentration of 10 000 cells/50 microliters. The determination of aspartate aminotransferase (ASAT) release, measured with a centrifugal analyser parallels lactate dehydrogenase (LDH) release and trypan blue dye staining which are indisputable markers of cell death, but ASAT release is a more sensitive determination. Surprisingly, 51chromium release (1.72%/h) is much higher than ASAT release (0.51%/h) for an experimental period of 24 h. In cell mediated cytotoxicity tests, the ASAT content of lymphocytes, in contrast to that of LDH, is much lower than that of hepatocytes and this makes determination of ASAT release a sensitive marker of cytotoxicity under these conditions.

Time course of islet cell antibodies in diabetic and nondiabetic BB rats.

The BB rat develops a spontaneous type I diabetic syndrome with anti-islet autoimmunity. Sera from diabetic and nondiabetic BB rats (from diabetes-prone litters), nondiabetic BB rats (from low-risk lines), and nondiabetes-prone Sprague-Dawley rats were collected twice a week from age 40 days to 160 days. Sera were tested for: (1) complement-dependent toxicity to 51Crlabeled islet cells in vitro; (2) immunoglobulin binding to RIN-5 F insulinoma cells; and (3) ability to selectively suppress insulin secretion from normal islets in vitro. All sera from rats that subsequently became diabetic or glucose-intolerant were toxic to islet cells from various rat strains in the presence of complement. They were toxic neither to hepatocytes nor to fibroblasts. The toxic potency was associated with the globulin fraction. It was, in most cases, maximal either before or immediately after the onset of the disease. Sera from the nondiabetes-susceptible BB rats and the rats which, in diabetes-prone litters, died too early to be classified tended toward greater toxicity to islets. Immunoglobulins from diabetic sera bound to RIN-5 F cells more than did the serum globulins from other groups, their maximal binding capacity occurring afterthe onset of diabetes. Furthermore, BB diabetic sera were capable of selectively inhibiting the insulin secretion from normal rat islets in vitro either in the presence or, in some cases, in theabsence of complement. The A- and D-cell functions were not suppressed. The combination of such results suggests the presence of one or more antibodies capable of binding to beta cells, inhibiting their function, and inducing their lysis. These antibodies may contribute to the beta cell disruption in this model of diabetes.

Hypersensitivity to insulin during remissions in cyclosporin-treated IDDM patients

OBJECTIVE— To test the sensitivity to insulin in recent-onset IDDM patients, its course according to treatment, and the advent of remissions. RESEARCH DESIGN AND METHODS— The euglycemic hyperinsulinemic clamp was used in 54 recent-onset IDDM patients and 14 healthy control subjects. Patients were tested after 1,2, and 4 wk of treatment with either insulin or insulin plus cyclosporin A, during cyclosporin A-associated long-lasting remissions, and during relapses. RESULTS— Insulin sensitivity was markedly decreased in all patients at onset. It was rapidly restored by insulin therapy, whether immunosuppression was associated with it or not. Insulin sensitivity was even higher than normal in the remission patients, who also were characterized by the reappearance of some endogenous insulin secretion and the sustained normalization of blood glucose profiles. During relapses, the deterioration of the blood glucose profiles was associated with some loss of insulin sensitivity. CONCLUSIONS— Cyclosporin A-associated remissions represent an original situation that associates euglycemia with the persistence of low endogenous insulin secretion. Cyclosporin A by itself had no influence on sensitivity to insulin, but allowed the reappearance of some insulin secretory capacity that contributed, with the improvement of insulin sensitivity, to the development of the diabetes honeymoon. The secretion of endogenous insulin, although lower than normal, was sufficient to secure a high sensitivity to insulin and the maintenance of normal blood glucose profiles, presumably because of the fact that insulin was released directly into the portal vein in these conditions. This metabolic state was precarious: the optimal sensitivity to insulin disappeared in patients who relapsed. These results have important clinical consequences: the preservation of islet residual secretory capacity by the use of newer nontoxic immunosuppressive protocols, combined with a minimal supportive insulin therapy in remission patients, may prolong remissions and maintain an optimal insulin sensitivity.

Phagocyte oxidative metabolism in cyclosporine- or placebo-treated patients with insulin-dependent (type I) diabetes mellitus of recent onset.

Several lines of evidence suggest that phagocyte-mediated oxidative processes are involved in damage to pancreatic islet cells of Type I insulin-dependent diabetes mellitus (IDDM). This hypothesis, however, has not yet been explored at the clinical onset of IDDM. Similarly, the possibility that cyclosporine A (Cy-A) might exert a selective influence on these phagocyte-mediated oxidative reactions has also not yet been investigated as compared to a placebo. The present study tested both hypotheses in 32 patients with recently diagnosed IDDM who were part of the recent French multicenter randomized therapeutic trial of Cy-A. The production of reactive oxygen intermediates (ROI) by circulating polymorphonuclear (PMN) and mononuclear (MN) phagocytes was determined by luminol-dependent chemiluminescence (CL), both directly within microamounts of whole blood and in purified PMN or MN phagocyte suspensions. Lastly, CL production was measured in the absence (resting CL) and the presence of a panel of particular and soluble phagocyte membrane-stimulating agents. We found that on entry into the trial, i.e. within less than 2 months of the clinical onset of IDDM, patients had normal whole blood CL production in the absence of a stimulating agent and upon phagocytic challenge with latex or opsonised zymosan particles. By contrast, whole blood CL responses to soluble stimuli such as phorbol myristate acetate (PMA), concanavalin A (Con-A) and F Met-Leu-Phe (FMLP) were significantly higher than in the control group of 52 normal subjects (P less than 0.01). In purified PMN and MN phagocyte suspensions, both resting and stimulated CL productions were normal, regardless of the type of stimulating agent. After 3 months of treatment, whole blood CL responses to Con-A and FMLP returned to almost normal levels in patients treated with Cy-A (15 cases) but not in those receiving the placebo (17 cases); PMA-induced CL responses were also decreased, but this was found in both groups of patients. In purified phagocyte suspensions we detected no effect of Cy-A on PMN, whereas MN phagocytes from Cy-A-treated patients showed reduced CL responses to FMLP but not to other stimuli. Altogether, these results demonstrate for the first time that the capacity of circulating PMN and MN phagocytes to generate ROI is normal at the clinical onset of IDDM and suggest that circulating substances increase oxidative responses to soluble, but not particulate, stimuli.(ABSTRACT TRUNCATED AT 400 WORDS)

Epstein-Barr virus serology and isoelectrofocusing pattern of serum immunoglobulins in cyclosporin or placebo-treated type I diabetics

Epstein-Barr virus (EBV) serology was serially studied for a period of 18 months in 49 recently diagnosed type I diabetics randomly assigned to receive cyclosporin (CsA) (n = 25) or placebo (n = 24). Additionally, isoelectrofocusing of serum (IEF) was serially performed in 59 CsA- and 38 placebo-treated diabetics, over a 36 month period (687 sera) in order to detect restriction of heterogeneity of circulating immunoglobulins. Patients were continuously treated with CsA at a dose of 7.5-10 mg/day during the first 6 months and a dose not exceeding 5 mg/kg/day, thereafter. Before treatment anti-EBV antibody levels were in the normal range for the whole group. In the placebo group, Epstein-Barr nuclear antigen (EBNA) and viral capsid antigens (VCA) IgG were moderately raised during the first 6 months in comparison with baseline level (0.33 +/- 0.13 and 0.30 +/- 0.18 two-fold dilutions respectively). In contrast, in the CsA group, EBNA and VCA IgG decreased slightly (0.26 +/- 0.16 and 0.26 +/- 0.17 dilutions). Changes between the two groups at 3 and 6 months were significantly different (P less than 0.05), but the difference disappeared subsequently. No significant changes in anti-early antigen (EA) IgG and in EA and VCA IgA were observed. No IEF abnormalities appeared in the CsA group. One CsA-treated patient who was initially EBV seronegative developed normal serological signs of recent EBV infection at 12 months without restriction of immunoglobulin heterogeneity or clinical symptoms of infectious mononucleosis. This study indicates that CsA, at moderate dosage, slightly reduces the titer of pre-existing anti-EBV antibodies but does not alter the response to recent EBV infection. These results do not provide any evidence of clinically latent EBV-induced benign or malignant lymphocyte proliferation.

Therapeutic Immunosuppression in Type I (Insulin-dependent) Diabetes

Publisher Summary This chapter presents the therapeutic immunosuppression in type I (insulin-dependent) diabetes. The autoimmune hypothesis of the origin of type I (insulin-dependent) diabetes mellitus is based on numerous data obtained both from human and animal models (BB rat and NOD mouse). The immunological aggression mainly involves T lymphocyte-mediated immunity. It results in the selective destruction of insulin-secreting cells (beta-cells) in the pancreatic islets of Langerhans, following an intense lymphocytic infiltration (insulitis). In most patients, the clinical course paralleled the evolution of insulin secretion capacity measured by plasma C peptide secretion following glucagon injection. The study of the humoral and cellular immune status of Cy-A-treated patients has provided interesting information on the immunological mechanisms by which Cy-A preserved the residual beta cell mass. Cyclosporine had only minimal effects on the production of anti-insulin and anti-islet cell antibodies whether directed to islet cytoplasmic antigens as detected by immunofluorescence (ICA) or membrane antigens as evaluated in a cytotoxicity assay, even in patients undergoing remission.