Cytokine plasma levels and lymphocyte subsets in patients with newly diagnosed insulin-dependent (type 1) diabetes mellitus before and following initial insulin treatment

The role of cytokines and vitamin D in vitiligo pathogenesis

Vitiligo is a pigment-related disease with a global prevalence of 0.2% to 1.8% associated with considerable burden on quality of life. The treatment is still a challenge because of relapses and/or incomplete re-pigmentation. Although the exact cause is still unclear, its pathogenesis seems to be justifiable with the autoimmune theory, supported by the results of clinical research. In this narrative review, we aimed to summarize the evidence related to cytokines and vitiligo development. This review is consisted of English articles published in PubMed and Google Scholar concerning levels of inflammatory mediators, especially interleukins, in vitiligo patients over the last 20 years. References of relevant articles were also considered for review. Crucial role of dysregulated levels of interleukins and their synergistic function to each other, in the onset or progression of the disease is evident. The theory of autoimmune vitiligo is reinforced by the results of the studies in the literature, due to the association of pathogenesis with increased secretion of pro-inflammatory mediators and reduction of anti-inflammatory mediators. Decreased vitamin D levels may have a considerable role in vitiligo development by affecting Th1- and Th17-related immune responses. Cytokines play an important role in the pathogenesis or progression of the disease. Moreover, we believe that decreased vitamin D level has a considerable role in vitiligo development by affecting Th1- and Th17-related immune responses.

Factors Associated with Higher Pro-Inflammatory Tumor Necrosis Factor-α Levels in Young Women with Type 1 Diabetes

AIMS

While cytokines play a role in the etiology of type 1 diabetes, cytokines later in the disease are less understood. We therefore investigated associations of pro-inflammatory tumor necrosis factor-α levels measured at prolonged disease duration with C-peptide at diagnosis, long-term glycemic control, diabetes duration, clinical factors, and health behaviors.

METHODS

Data and blood were collected during an ancillary study to the longitudinal Wisconsin Diabetes Registry, a population-based cohort followed since diagnosis of type 1 diabetes. The ancillary study was conducted at 13-18 years diabetes duration, and enrolled premenopausal women age 18-45 years (n=87).

RESULTS

Higher tumor necrosis factor-α levels at 13-18 years diabetes duration were independently associated with longer duration (p=0.0004) and worse current renal function (p=0.02). Additionally, diabetes duration modified both of the positive associations of tumor necrosis factor-α levels (both interactions p≤0.01) with mean glycemic control during the previous 10 years (significant only in women with longer durations) and current daily caffeine intake (significant only in women with shorter durations). In women with C-peptide measured at diagnosis (n=50), higher tumor necrosis factor-α levels at 13-18 years duration were associated with lower C-peptide (p=0.01), independent of glycemic control during the previous 10 years.

CONCLUSIONS

Lower residual C-peptide at diagnosis and poor long-term glycemic control independently predicted higher pro-inflammatory tumor necrosis factor-α levels years later. The novel relationship with C-peptide needs confirmation in a larger cohort. Given the association between tumor necrosis factor-α and diabetes complications, further longitudinal studies may help clarify the potentially complex associations between glycemic control, inflammatory cytokines, and complications.

Responses of GLP1-secreting L-cells to cytotoxicity resemble pancreatic β-cells but not α-cells

Little is known about responses of intestinal L-cells to chemical or cytokine-mediated attack and how these compare with pancreatic β- or α-cells. Administration of streptozotocin to mice induced severe diabetes, islet lymphocytic infiltration, increased α-cell proliferation and decreased numbers of β- and L-cells. In vitro, streptozotocin and cytokines reduced cell viability with higher lethal dose 50 values for α-TC1 cells. mRNA expression of Glut2 was lower and Cat was greater in GLUTag and α-TC1 cells compared with MIN6 cells. Cytotoxins affected the transcription of genes involved in secretion in GLUTag and MIN6 cells. They are also involved in upregulation of antioxidant defence enzymes, transcription of NfκB and Nos2, and production of nitrite in all cell types. Cytotoxin-induced DNA damage and apoptosis were apparent in all cells, but α-TC1 cells were less severely affected. Thus, responses of GLP1-secreting L-cells to cytotoxicity resemble β-cells, whereas α-cells are resistant due to differences in the expression of genes involved in cytotoxicity or antioxidant defence.

Fibroblasts from type 1 diabetics exhibit enhanced Ca(2+) mobilization after TNF or fat exposure

The effects of cytokine and fatty acid treatment on signal transduction in dermal fibroblasts from type 1 diabetics and matched controls were compared. Chronic exposure to TNF, accentuated Ca²⁺ mobilization in response to bradykinin (BK) in cells from both controls and diabetics; responses were three-fold greater in cells from diabetics than in controls. Similarly, with chronic exposure to IL-1β, BK-induced Ca²⁺ mobilization was accentuated in cells from type 1 diabetics compared to the controls. Pretreatment with the protein synthesis inhibitor cycloheximide or the protein kinase C inhibitor calphostin C prior to the addition of TNF completely abrogated the TNF-induced increment in peak bradykinin response. Ca²⁺ transients induced by depleting endoplasmic reticulum (ER) Ca²⁺ with thapsigargin were also greater in TNF treated fibroblasts than in untreated cells, with greater increases in cells from diabetics. Exposing fibroblasts for 48 hours to 2 mM oleate also increased both the peak bradykinin response and the TNF-induced increment in peak response, which were significantly greater in diabetics than controls. These data indicate that cells from diabetic patients acquire elevated ER Ca²⁺ stores in response to both cytokines and free fatty acids,and thus exhibit greater sensitivity to environmental inflammatory stimuli and elevated lipids.

Serum concentration of IL-6, IL-2, TNF-α, and IFNγ in Vitiligo patients

Background:

Vitiligo is an acquired depigmenting disorder characterized by the loss of functional melanocytes from the epidermis. Although the etiology of vitiligo is unknown, over the last few years, substantial data from clinical research has greatly supported the ‘Autoimmune theory’ and this is supported by the frequent association of vitiligo with disorders that have an autoimmune origin, including Hashimoto's thyroiditis, Graves disease, type 1 insulin-dependent diabetes mellitus, and Addison's disease. As cytokines are important mediators of immunity, there is evidence to suggest that they play a major role in the pathogenesis of autoimmune diseases.

Aim:

Keeping this in view we have assayed sera for cytokine IL-6, IL-2, Tumor necrosis factor (TNF)-α, and IFNγ in 80 cases of vitiligo and compared it with healthy subjects, in order to find out whether they play a role in the pathogenesis of vitiligo or not.

Materials and Methods:

Serum IL-6, IL-2, TNF-α, and IFNγ were done by the indirect enzyme linked immunosorbent assay (ELISA).

Results:

The mean serum IL-6 and IL-2 levels in the patient group were significantly higher when compared with those of the normal controls. The mean serum IFNγ level in patients with vitiligo was significantly lower than that in the control group. There was no significant difference in the serum level of TNF-α between vitiligo and healthy controls.

Conclusion:

An increase in the production of proinflammatory cytokines such as IL-6 and IL-2 in vitiligo patients may play an important role in melanocytic cytotoxicity. Thus, we speculate that the cytokine production of epidermal microenvironment may be involved in vitiligo.

Modulatory role of green tea extract on antinociceptive effect of morphine in diabetic mice

Diabetic neuropathic pain is an important microvascular complication, and morphine has been demonstrated to be ineffective in this condition. Therefore the present study was designed to investigate the modulatory effect of green tea extract (GTE) on the decreased antinociceptive effect of morphine in diabetic mice. The tail withdrawal test was performed for measurement of the nociceptive threshold in both streptozotocin (STZ)-injected and control mice. Four weeks after administration of STZ, antinociception of morphine (5 mg/kg, s.c.) alone or in combination with GTE (25, 50, and 100 mg/kg, i.p.) was measured. Experimental diabetes markedly decreased the antinociceptive effect of morphine. The decrement in morphine response was significantly attenuated by GTE administration. When GTE (25 mg/kg) and a nitric oxide (NO) inhibitor, L-N(G)-nitroarginine methyl ester (L-NAME) (10 mg/kg, i.p), were co-administered along with morphine (5 mg/kg, s.c) in diabetic mice, the antinociceptive action of morphine was significantly increased as compared with the GTE + morphine-treated diabetic group, but the increased antinociceptive action was significantly attenuated by administration of an NO precursor, L-arginine (100 mg/kg, i.p), instead of L-NAME. Plasma nitrite concentrations were estimated using the Griess reagent. Diabetes significantly increased the plasma nitrite levels that were attenuated by GTE administration. When GTE (25 mg/kg) and L-NAME (10 mg/kg, i.p) were co-administered along with morphine (5 mg/kg, s.c) in diabetic mice, the plasma nitrite levels were significantly decreased as compared with the GTE + morphine alone-treated diabetic group, but the decreased plasma nitrite levels were significantly reversed by administration of L-arginine (100 mg/kg) instead of L-NAME. It may be concluded that increased NO formation may be responsible for the decreased antinociceptive effect of morphine in diabetic mice and that GTE restored the antinociceptive effect of morphine by inhibition of NO production. The results of the present study indicate the possibility of adding GTE as an adjuvant in the treatment of diabetic neuropathic pain.

Transforming growth factor beta at clinical onset of Type 1 diabetes mellitus. A pilot study

AIMS

The aims of the study were to determine whether transforming growth factor beta1 TGF-beta1 levels are raised at diagnosis of Type 1 diabetes mellitus and are related to blood glucose.

SUBJECTS AND METHODS

Fourteen patients (mean age 24.3 +/- 4.9 years) admitted to hospital for onset of Type 1 diabetes were studied. On the first day of hospitalization, before insulin therapy, and at 1, 4 and 16 weeks, fasting blood glucose, HbA(1c), lipid profile and TGF-beta1 levels and TGF-beta1 levels in 24-h urine were determined. The control group included 14 non-diabetic subjects with similar characteristics to those of the diabetic group.

RESULTS

Plasma and urinary TGF-beta1 levels were significantly lower in controls (4.7 (1.6-6.8) ng/ml P < 0.001; 5.7 (1.5-8.5) ng/mg urinary creatinine, P < 0.01) than in patients with Type 1 diabetes mellitus [10.5 (1.8-24.9) ng/ml; 10.1 (4.2-29.8) ng/mg urinary creatinine]. On study completion, HbA(1c) fell from 11.6 +/- 2.0 to 5.4 +/- 0.6% (P < 0.001). Improved metabolic control was not associated with changes in plasma (9.4 (2.6-19.5)/5.9 (1.6-21.5)/7.0 (2.3-30.2)/10.5 (1.8-24.9) ng/ml at baseline, 1, 4 and 16 weeks, respectively) or urinary (12.0 (4.7-29.5)/10.9 (1.5-20.5)/8.7 (4.3-16.9)/10.1 (4.2-29.8) ng/mg urinary creatinine) TGF-beta1 levels. A statistically significant correlation was observed between plasma TGF-beta1 and insulin dosage (U/kg/day) (r = 0.52, P = 0.037).

CONCLUSIONS

The increased TGF-beta1 production observed herein was not modulated by glycaemic reduction and could be a response to immuno-inflammatory activation present at the onset of Type 1 diabetes.

Cytokine response to diabetic ketoacidosis and its treatment

The objectives of this study were to monitor plasma cytokines as markers of cellular activation and as potential markers for the progression of the acute complications of diabetic ketoacidosis (DKA). Blood samples were obtained prior to, during and after treatment of severe DKA (pH < 7.2) in six children and adolescents. Plasma IL-10, IL-1beta, TNF-alpha, IL-6, IL-8 and IL-2 cytokine levels were assayed by ELISA at each of the time points. Prior to treatment, elevations of multiple cytokines were found, the highest being IL-10. Treatment of DKA resulted in a significant decrease of IL-10 at 6-8 h (p = 0.0062), and further increases in the inflammatory cytokines at 6-8 h and/or 24 h vs 120 h (baseline): IL-1beta (p =.0048); TNF-alpha (p =.0188) and IL-8 (p =.0048). This study strengthens the hypothesis that the metabolic crisis of DKA, and its treatment, have differential effects on cellular activation and cytokine release. The time frame for the increase in inflammatory cytokines correlates with the reported progression of subclinical brain edema, interstitial pulmonary edema and the development of clinical brain edema.

An association of autoantibody status and serum cytokine levels in type 1 diabetes

At onset of type 1 diabetes, the islet autoantibody status of patients has been reported to predict progression of the disease. We therefore tested the hypothesis that the systemic immunoregulatory balance, as defined by levels of circulating cytokines and chemokines, is associated with islet autoantibody status. In 50 patients with recent-onset type 1 diabetes, antibodies to GAD and insulinoma-associated antigen 2 (IA-2) were analyzed by radioimmunoassay; cytoplasmic islet cell antibodies were determined by indirect immunofluorescence. Cytokine and chemokine concentrations were measured by rigidly evaluated double antibody enzyme-linked immunosorbent assay. Of four classically defined Th1/Th2 cytokines (gamma-interferon, interleukin [IL]-5, IL-10, IL-13), none showed an association with multiple autoantibody positivity. Of six mediators mainly produced by innate immunity cells, three were associated with multiple autoantibody status (IL-18 increased, MIF and MCP-1 decreased) and three were unaffected (IL-12, MIP-1beta, IP-10). GAD and/or IA-2 antibody titers negatively correlated with systemic concentrations of MIF, MIP-1beta, and IL-12. Combining the data of several cytokine and chemokine levels made it possible to predict islet antibody positivity in individual patients with 85% sensitivity and 94% specificity. These data suggest a close association of islet antibody status with systemic immunoregulation in type 1 diabetes.

Increased interleukin-6 and granulocyte-macrophage colony stimulating factor levels in the sera of patients with non-segmental vitiligo

BACKGROUND

Although the cause of vitiligo is unknown, an autoimmune theory has been proposed, and there is now convincing evidence that cytokines have an important role in pathogenesis of autoimmunity.

OBJECTIVE

To study the possible role of interleukin-1, beta (IL-1 beta), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-alpha) and granulocyte-macrophage colony stimulating factor (GM-CSF) in the pathogenesis of vitiligo.

METHODS

The authors measured the serum levels of the above-mentioned cytokines from 50 patients with the vitiligo compared with 20 healthy volunteers, employing the method of radioimmunoassay.

RESULTS

The results showed that the serum levels of both IL-6 and GM-CSF of the patients with both focal type and generalized type of vitiligo, and the serum level of IL-1 beta of the generalized type,were significantly, higher than those of normal controls in the patients with segmental vitiligo, the serum levels of all the cytokines tested were not significantly different from those of the normal controls. The GM-CSF levels of both focal type and generalized type, and the IL-6 level of the generalized type in progressive stage were significantly higher than those in stable state.

CONCLUSION

It is speculated that IL-6 and GM-CSF may be involved in the autoimmune mechanism of non-segmental vitiligo. However, more evidence is required before a definite conclusion can be drawn.

The interaction between IL-1beta and morphine: possible mechanism of the deficiency of morphine-induced analgesia in diabetic mice

It is known that diabetic mice are less sensitive to the analgesic effect of morphine. Some factor(s) derived from mononuclear cells, e.g. interleukin-1beta (IL-1beta), may be responsible for the diminished analgesic effect of morphine in diabetic mice. Therefore, we examined direct effects of IL-1beta, intracerebroventricularly (i.c.v.), on morphine-induced analgesia, subcutaneously (s.c.), in diabetic and control mice by using the tail-flick test. Morphine at doses of 1, 2 and 5 mg/kg (s.c.) produced dose-dependent analgesia in diabetic and control mice but diabetic mice were less sensitive to the analgesic effect of morphine when compared to the controls. IL-1beta at a dose of 0.1 ng/mouse produced analgesia in control mice but not in diabetics, whereas IL-1beta at a dose of 10 ng/mouse produced a hyperalgesic effect both in diabetic and control mice. IL-1beta at a dose of 1 ng/mouse has neither an analgesic nor a hyperalgesic effect in control and diabetic mice. Administration of a neutral (neither analgesic nor hyperalgesic) dose of IL-1beta, 1 ng/mouse (i.c.v.), just prior to administration of morphine (s.c.) abolished the analgesic effect of morphine at doses of 1, 2 and 5 mg/kg in control mice and the analgesic effect of morphine became similar to that in diabetics. The diminished analgesic effect of morphine in diabetes was attenuated further with IL-1beta at a dose of 1 ng/mouse (i.c.v.). These results suggest that the decreased analgesic effect of morphine in diabetes may be related to IL-1beta.

Systemic levels of cytokines and GAD-specific autoantibodies isotypes in Chinese IDDM patients

It is not clear if a Th1/Th2 imbalance in Type 1 diabetes (insulin-dependent diabetes mellitus, IDDM) would lead to a particular antigen-specific IgG subclass dominant as had been shown in the mouse model. In new-onset Type 1 diabetics, an autoantibody response to glutamate decarboxylase (GADab) is frequently observed but the GADab subclass repertoire is not well-established. We determined the systemic levels of representative Th1 and Th2 cytokines and the GADab IgG subclass distribution in 41 Chinese IDDM patients of whom 26 were recently diagnosed (< or = 1 year) and 32 had GADab, to ascertain a likely association of antigen-specific antibody isotype and the Th1/Th2 dichotomy. With high-sensitivity ELISA systems that measure sub-picogram cytokine concentrations, 26 of the 41 patients (63.4%) had at least one of the pro-inflammatory Th1 cytokines (TNF-alpha, IFN-gamma and IL-12) detected. Fewer patients (4/41) had the anti-inflammatory Th2 cytokine IL-4 detected. For IL-10, all subjects had measurable quantities but only three diabetics had levels above the upper limit for healthy subjects (n = 20). Grouped according to the profile of detectable cytokines, there were 24 Th1, 2 Th2 and 2 Th0 patterns. GAD-specific IgG1 antibody was more frequently expressed; 22 of 32 GADab[+] patients. The rank order for the GADab subclasses was IgG1 > 4 > 3 > 2; IgG2 was found in 11 GADab[+] patients. Recent-onset diabetics have a similar ranking of the GAD-specific IgG subclasses. In human Type 1 diabetes, a predominance of GAD-specific IgG1 antibody response is observed together with a dominant Th1 cytokine pattern.

Decreased secretion of Th2 cytokines precedes Up-regulated and delayed secretion of Th1 cytokines in activated peripheral blood mononuclear cells from patients with insulin-dependent diabetes mellitus

Recent evidence suggests that autoimmune animal diabetes is associated with an imbalance between the Th1 and Th2 arms of the cellular immune system. However, limited data is available regarding the Th1/Th2 imbalance in human Insulin dependent diabetes mellitus (IDDM) patients. Therefore, we examined the peak levels, secretory pattern and total cytokine production (calculated as the area under the curve, AUC) of the Th1 cytokines, IL-2 and IFN-gamma, and Th2 cytokines, IL-4 and IL-10, from stimulated peripheral blood mononuclear cells, from 17 IDDM patients and 24 normal controls. In contrast to controls, diabetic patients were characterized by an early, uniformly low secretion of Th2 cytokines, followed by a late increased secretion of Th1 cytokines. This resulted in significant differences in secretory patterns of IFN-gammaIL-2, IL-4 and IL-10 between the two groups; P<0.001, P<0.005, P<0.005 and P<0.001, respectively. No correlation was found in the diabetic patients between any profiles of the cytokines and their various clinical parameters, including age, gender, disease duration, insulin requirements or glycated hemoglobin levels. In conclusion, our data provides the first comprehensive evidence for an independent and persistent impairment of both Th1 and Th2 cytokine secretory patterns in IDDM patients.

Elevated serum levels of macrophage-derived cytokines precede and accompany the onset of IDDM

To determine whether cytokines could have a role in the development of insulin-dependent diabetes mellitus (IDDM), we measured serum levels of cytokines derived from T helper 1 (interleukin-2 and interferon-gamma), T helper 2 (interleukin-4 and interleukin-10) lymphocytes and macrophages (tumour necrosis factor-alpha, interleukin-1 alpha and interleukin-1 beta) in patients before and after the onset of IDDM. Recently diagnosed IDDM patients had significantly higher levels of interleukin-2, interferon-gamma, tumour necrosis factor-alpha and interleukin-1 alpha than patients with either long-standing IDDM, non-insulin-dependent diabetes (NIDDM), Graves' disease, or control subjects (p < 0.05 for all). Compared with control subjects, patients with long-standing IDDM and those with NIDDM had higher interleukin-2 and tumour necrosis factor-alpha levels (p < 0.01 for all). Interleukin-4 and interleukin-10 were detectable in sera of patients with Graves' disease only, while interleukin-1 beta was not detectable in the serum of any control or test subject. To investigate whether high cytokine levels precede the onset of IDDM, we studied 28 non-diabetic identical co-twins of patients with IDDM, followed-up prospectively for up to 6 years after the diagnosis of the index. Levels of tumour necrosis factor-alpha and interleukin-1 alpha were elevated above the normal range more frequently in the eight twins who developed diabetes than in those 20 who did not (p < 0.005). Analysis of T helper 1 and T helper 2 profiles of the twin groups did not reveal a clear difference between prediabetic twins and twins remaining non-diabetic. These results support the notion that T helper 1 lymphocytes may play a role in the development of IDDM. This is associated with release of macrophage-derived cytokines, which is also a feature of the prediabetic period. The lack of evidence of a dominant T helper 1 profile of cytokine release before diabetes onset suggests that additional events, activating this arm of the cellular immune response, are required in the immediate prediabetic period.

Interleukin-1 beta: a common cause of Alzheimer's disease and diabetes mellitus

Alzheimer disease is characterized by the presence of beta-amyloid protein deposits, neurofibrillary tangles and cholinergic dysfunction throughout the hippocampal region. In addition, the hippocampus, hypothalamus and olfactory bulb--the three areas where the insulin receptors are most dense--are also subject to neurodegeneration. The exact cause of the beta-amyloid deposits and NFTs is unknown. However, it is our intention to explicate the various pathogenic pathways through which Alzheimer disease arises. Fundamentally, the structural and metabolic damage found in Alzheimer disease is due to sustained elevation of interleukin-1 beta, a feature which is also found in insulin-dependent diabetes mellitus. Similarly, the beta-AP deposits found in the Alzheimer brain share the same molecular structure as the amylin deposits found in the pancreatic beta-cells in non-insulin-dependent diabetes mellitus (NIDDM), and are equally neurotoxic. These, and other pathophysiological parallels, afford some insight into the probably cause of Alzheimer disease and, as such, forms the basis of the causal hypothesis advanced in this paper.

Plasma levels of IL-1, TNF alpha, IL-6, IL-8, G-CSF, and IL1-RA during febrile neutropenia: results of a prospective study in patients undergoing chemotherapy for acute myelogenous leukemia

Plasma levels of IL-1, IL-6, IL-8, IL1-RA, TNF alpha, and G-CSF were prospectively studied during 23 chemotherapy cycles of 20 patients suffering from acute myelogenous leukemia. Increased plasma levels of IL-6, IL-8, and G-CSF were observed in patients with febrile neutropenia and/or major infection. Plasma levels of IL-6, IL-1, TNF alpha and IL-1-RA measured 1 day before and 1 day after the onset of febrile episodes did not accurately predict the development of major infection. In contrast, IL-8 plasma levels were significantly higher in those patients who subsequently developed major infection. The question whether IL-8 plasma levels identify high risk or low risk patients with sufficient specificity and sensitivity has to be answered in large scale clinical trials.