Hepatotoxicity of antiretroviral drugs.

The use of highly active antiretroviral therapy (HAART) has significantly slowed the HIV disease progression. However, adverse effects are now a limiting cause of HAART benefit in a substantial proportion of patients. Particularly hepatotoxicity which is a common complication occurring during every HAART regimen. All antiretroviral (ARV) drugs classes, Nucleoside/Nucleotide reverse transcriptase inhibitors (NRTI), non-Nucleoside reverse transcriptase inhibitors (nNRTI) and Protease Inhibitors (PI) may cause hepatotoxicity but in different pathways. Many risk factors have been identified for developing antiretroviral-related hepatotoxicity, however severe hepatitis remains very uncommon in patients receiving HAART, also if the incidence of hepatotoxicity is rather high. That being the case, means that every new available antiretroviral drug strongly necessities studies which can evaluate its hepatotoxicity and drug-drug interactions, to define the potential risk factors and the outcome of any side effects. This report will review the risk factors, the epidemiology and the pathogenic mechanisms of hepatotoxicity caused in every antiretroviral drug.

Autoantibodies in recent onset type-1 diabetic patients to a Mr 60K microsomal hepatic protein: new evidence for autoantibodies to the type-2 glucose transporter.

Here we describe the presence of IgG antibodies, in the sera of patients presenting with insulin-dependent diabetes mellitus (IDDM), that react in Western blots with a 60-kD protein (Mr 60K) from rat hepatic microsomal extracts. Sera from 60 IDDM patients were screened and 31.6% were positive for the Mr 60K band. This antibody reactivity was indistinguishable in terms of both molecular weight and isoelectric point (pI 5.4) from that described in some patients presenting with autoimmune hepatitis who may also develop IDDM. We hypothesized that the type-2 glucose transporter (Glut-2) that is expressed on both hepatocytes and pancreatic beta cells could be a putative target for the detected antibodies. A polyclonal antisera to rat Glut-2 used in the liver microsome Western blot identified a 60-kD band superimposable upon that evidenced by IDDM sera. Antisera to Glut-2 successfully inhibited the binding of the patient's IgGs to liver microsomes, further suggesting that the two proteins may be identical. Using protein extracts from a rat insulinoma cell line (RIN) transfected with the human Glut-2 cDNA, further evidence was obtained suggesting that these IDDM IgGs are specific for the human Glut-2 transporter.

Anti-bovine serum albumin antibodies: genetic heterogeneity and clinical relevance in adult-onset IDDM.

OBJECTIVE: To evaluate the prevalence of anti-bovine serum albumin (BSA) antibodies in patients with adult-onset insulin-dependent diabetes mellitus (IDDM) and investigate a possible link between their presence and genetic susceptibility or resistance determined by human leukocyte antigen (HLA) complex. RESEARCH DESIGN AND METHODS: Sera from 60 recent-onset diabetic patients, 5 prediabetic subjects, and 102 healthy control subjects were tested using a radioimmunoprecipitation assay. HLA-DRB and -DQB alleles were determined by means of allele-specific oligonucleotide typing. Islet cell antibodies (ICAs) were assayed by indirect immunofluorescence. RESULTS: Levels of anti-BSA antibodies were significantly higher in IDDM patients (18.1 +/- 3.5%, n = 60) than in healthy control subjects (7.5 +/- 1.2%, n = 102) (P < 0.001), but in only 16.6% of IDDM patients (10 of 60) were the titers above the 95th percentile of control values. Anti-BSA antibody titers were higher in HLA-DR3 and/or -DR4 patients (23.4 +/- 4.9%, n = 41) compared with DR3 and/or DR4 control subjects (3.1 +/- 1.0%, n = 10) (P < 0.001). DR3 IDDM patients showed higher levels of anti-BSA antibodies (26.3 +/- 6.3%, n = 30) than non-DR3 patients (9.9 +/- 2.6%, n = 30) (P < 0.01) and healthy control subjects. Only two out of five prediabetic subjects had significant anti-BSA levels before clinical onset of diabetes. CONCLUSIONS: Our data confirm that antibodies to BSA are present in adult-onset IDDM patients, particularly in HLA-DR3-positive patients. However, the prevalence of anti-BSA antibodies was lower than previously reported in children, and there was a considerable overlap with healthy control subjects. Only two out of the five prediabetic patients demonstrated anti-BSA antibodies. Taken together, these results do not bring strong support to the clinical usefulness of anti-BSA antibodies as a relevant marker in diabetes prediction or diagnosis.

Aberrant function and long-term survival of mouse beta cells exposed in vitro to high glucose concentrations.

In vitro culture of murine Langerhans islets usually ends in islet death after 1-3 wk. Given contradictory published data, we studied the influence of glucose on the function and survival of islets from DBA/2 mice. Islets were cultured on plastic microwells, using 1, 2, or 11 g/l glucose concentrations. Using our routine technique, insulin secretion was evaluated after islet incubation for 15 min in basal medium [(sIS), 1 g/l glucose], followed by 15 min in stimulating medium [(sIS), 3 g/l glucose, 20 mM/l arginine, 5 mM/l theoophylline]. Insulin secretion of islets cultured in 1 g/l glucose remained stable and normal over a period of 2 mo [Day 7: bIS, 6.3 +/- 3.1 microU/50 microliters; sIS, 16.6 +/- 6.8 microU/50 microliters. Day 60: bIS, 6.0 +/- 4.0 microU/50 microliters; sIS, 21.3 +/- 10.5 microU/50 microliters]. Islet morphology also remained normal. Islets cultured in 2 g/l glucose showed elevated insulin response under basal and stimulating conditions during 2-3 wk, followed by a dramatic drop in insulin secretion [Day 7: bIS, 19.5 +/- 5.7 microU/50 microliters; sIS, 80.9 +/- 10.7 microU/50 microliters. Day 60: bIS, 5.4 +/- 5.0 microU/50 microliters; sIS, 2.7 +/- 1.4 microU/50 microliters]. Severe morphologic alterations appeared rapidly and islet destruction was nearly complete by 60 days. At 11 g/l glucose, functional and morphological islet alterations were accelerated [Day 7: bIS, 10.3 +/- 2.7 microU/50 microliters; sIS, 18.8 +/- 4.9 microU/50 microliters. Day 21: bIS and sIS almost undetectable].(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of interleukin-2 infusion on cell cycle kinetics in the Walker-256 carcinosarcoma.

The effect of recombinant human interleukin-2 (IL-2) on tumor cell cycle kinetics was evaluated in rats bearing the Walker-256 carcinosarcoma. Seven days after implantation, tumor-bearing rats were infused intravenously with IL-2 at a dose of 500 mg/kg body weight or 5% dextrose for 6 h. Tumor cell mean DNA synthesis time (TDNA), labeling index, potential doubling time (Tpot), and growth fraction (GF) were determined in vivo by use of bromodeoxyuridine (BrdUrd) pulse labeling and bivariate BrdUrd/DNA analysis using flow cytometry. IL-2 treatment significantly reduced the relative number of S-phase cells by 11.9% and increased the number of cells in the G0/G1 phase by 9.4%. The labeling index was reduced from 41.3 +/- 2.5% to 32.7 +/- 1.2% (P < .01). Estimates of TDNA derived from the change in BrdUrd movement relative to DNA content were not affected by IL-2 treatment. Based on these cytokinetic changes, IL-2 infusion significantly increased tumor Tpot from 15.3 +/- 0.3 h to 21.5 +/- 0.2 h (P < .001) and reduced GF from 1.01 +/- 0.07 to 0.83 +/- 0.01 (P < 0.001). The inhibitory effect of IL-2 infusion on tumor cell growth, which may be either direct or secondarily mediated by other factors, contrasts with other stimulatory effects of this cytokine on lymphoid cell proliferation.

DNA flow cytometric analysis and prognosis of axillary lymph node-negative breast carcinoma.

METHODS: The prognostic significance of flow cytometric analysis in patients with node-negative invasive breast carcinoma was evaluated in a retrospective series of 158 patients with a minimum follow-up study of 9 years. RESULTS: The ploidy status could be assessed in 147 specimens (93%), and the proliferative phase or S-phase fraction (SPF) could be assessed in 136 tumors (86%); 70 tumors (48%) were diploid, 49 tumors (33%) were aneuploid, and 28 tumors (19%) were tetraploid. Ploidy status and SPF were correlated significantly with tumor size, histologic grade, nuclear grade, and mitotic rate. By itself, ploidy was not a statistically significant prognostic factor, although all of the patients with multiploid and hypertetraploid tumors had recurrence of disease. The SPF was related significantly to recurrence of disease (P = 0.04). However, when multivariate analysis of various histopathologic variables was performed, SPF ceased to be a significant prognostic determinant, whereas peritumoral lymphovascular invasion was the most important variable. The combination of tumor size and flow cytometric parameters permitted stratification into three groups with different prognoses at the 9-year follow-up review (P less than 0.001). In the low-risk group (diploid tumors less than or equal to 2 cm in diameter with a low SPF or small tetraploid tumors), the recurrence rate was 12%. In the intermediate-risk group (diploid tumors greater than 2 cm in diameter with a low SPF or aneuploid tumors with a low SPF), the recurrence rate was 21%. In the high-risk group (diploid or aneuploid tumors with a high SPF or large tetraploid tumors), the recurrence rate was 49%. The high-risk group status remained a significant variable in the Cox proportional hazards multivariate analysis model. CONCLUSIONS: These results indicate that flow cytometry in breast carcinoma contributes useful but limited prognostic information and stress the importance of using multiple prognostic factors to improve prognostication and optimize patient management.

The effects of interleukin-1 on pancreatic beta cell function in vitro depend on the glucose concentration.

Insulin-dependent diabetes mellitus is characterized by progressive autoimmune destruction of pancreatic Beta cells mediated by ill-defined effector mechanisms. Experimental data suggest that cytokines, e.g. interleukin 1 and tumor necrosis factor, could play a fundamental role. The aim of this study was to analyze the effect of recombinant IL-1 beta (rIL-1 beta) on both islet functional capacity and morphology, using long-term cultures and various glucose concentrations. Islet cultured with 1 g/l (5.5 mmol/l) glucose maintained normal insulin- secretion and morphology for more than two months. In contrast, islets cultured with 2 g/l (11 mmol/l) glucose showed an altered insulin secretion and a shorter survival (40 days). At 11 g/l (60 mmol/l) glucose, islets died by 2 weeks of culture. rIL-1 beta exerted a cytotoxic effect on islet cells only when added to cultures containing supraphysiological glucose concentrations. But, in the presence of 1 g/l glucose, the addition of rIL-1 beta (40 ng/ml) for prolonged periods (14 days), did not alter islet function. Our results suggest that in auto-immune type I diabetes, IL-1 beta represents an aggravating factor in lesion formation more than a primary pathogenic mechanism.

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 greater than or equal to 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.(ABSTRACT TRUNCATED AT 250 WORDS)

[Polyendocrinopathy combined with primary pulmonary arterial hypertension]. / Polyendocrinopathie associée à une hypertension artérielle pulmonaire primitive.

We report the case of a woman who had premature menopause, adrenal insufficiency and hypothyroidism by peripheral gland lesion, all most probably due to an autoimmune disorder, and who subsequently developed primary pulmonary arterial hypertension. The causes of this hypertension are ill-defined, but an autoimmune origin has often been envisaged since primary pulmonary arterial hypertension is not unfrequently associated with connective tissue diseases. Its association with an autoimmune polyendocrinopathy has only been reported, to our knowledge, on four occasions; in all 4 cases the thyroid gland was involved, and a connective tissue disease was present in 3 of them. Our case, which includes adrenal insufficiency and premature menopause is, as far as we know, unique. The possible link between these various diseases is their autoimmune nature, in which case primary pulmonary arterial hypertension would belong to the category of organ-specific autoimmune diseases. Our case supports the hypothesis that a number of isolated primary pulmonary arterial hypertensions could be of autoimmune origin.

[How should the plasma ACTH level in treated Addison's disease patients be interpreted?]. / Comment interpréter l'ACTH plasmatique de l'addisonien traité?

The ACTH plasma levels of 73 treated Addisonian patients have been analysed and compared to those obtained in 40 normal subjects after metyrapone-induced nocturnal cortisol deprivation (75 to 700 pg/ml). Using this new criterion, it appears that patients with ACTH plasma levels lower than 75 pg/ml are most often over-treated; those with ACTH plasma levels between 75 to 700 pg/ml are most often well substituted; and those with ACTH plasma levels higher than 700 pg/ml are under-treated. In this latter group coincidental high plasma renin activity is generally present, pointing to the possible role of the renin-angiotensin system in maintaining high ACTH plasma levels.

Clinical comparison of glucose quantitation methods.

Quantitation of glucose in human serum, plasma, or whole blood by several commercially available methods and a manual hexokinase method were compared in various combinations. The techniques were selected as being representative of those available in large and small laboratory settings. Each differs as to reagent configuration and/or nature of sample required, such that a particular technique is more or less desirable depending on the unique situation of the user. Differences in relative performances in respect to accuracy and precision were revealed. Some are statistically significant and medically important. These differences must be appreciated by professionals of both large and small clinical laboratories, the managing physicians, and the patients.