Vitiligo: interplay between oxidative stress and immune system

Vitiligo is a multifactorial polygenic disorder with a complex pathogenesis, linked with both genetic and non-genetic factors. The precise modus operandi for vitiligo pathogenesis has remained elusive. Theories regarding loss of melanocytes are based on autoimmune, cytotoxic, oxidant-antioxidant and neural mechanisms. Reactive oxygen species (ROS) in excess have been documented in active vitiligo skin. Numerous proteins in addition to tyrosinase are affected. It is possible that oxidative stress is one among the main principal causes of vitiligo. However, there also exists ample evidence for altered immunological processes in vitiligo, particularly in chronic and progressive conditions. Both innate and adaptive arms of the immune system appear to be involved as a primary event or as a secondary promotive consequence. There is speculation on the interplay, if any, between ROS and the immune system in the pathogenesis of vitiligo. The article focuses on the scientific evidences linking oxidative stress and immune system to vitiligo pathogenesis giving credence to a convergent terminal pathway of oxidative stress-autoimmunity-mediated melanocyte loss.

High prevalence of insulin resistance in postpubertal Asian Indian children is associated with adverse truncal body fat patterning, abdominal adiposity and excess body fat

OBJECTIVE

The objectives were to study the relationships of insulin resistance with generalized and abdominal obesity, and body fat patterning in urban postpubertal Asian Indian children.

DESIGN

Cross-sectional, population-based epidemiological study.

SUBJECTS

In all, 250 (155 males and 95 females) healthy urban postpubertal children.

MEASUREMENTS

Anthropometric profile, percentage of body fat (%BF), fasting serum insulin, and lipoprotein profile.

RESULTS

Fasting insulin correlated significantly with body mass index (BMI), %BF, waist circumference (WC), central and peripheral skinfold thicknesses and sum of four skinfold thicknesses (Sigma 4SF) in both sexes, and with systolic blood pressure and waist-to hip circumference ratio (W-HR) in males only. Consistent increase in fasting insulin was noted with increasing values of central skinfold thickness at each tertile of peripheral skinfold thickness, WC, and %BF. Central skinfold thickness correlated with fasting insulin even after adjusting for WC, W-HR, and %BF. The odds ratios (OR) (95% CI) of hyperinsulinemia (fasting insulin concentrations in the highest quartile) were 4.7 (2.4-9.4) in overweight subjects, 8 (4.1-15.5) with high %BF, 6.4 (3.2-12.9) with high WC, 3.7 (1.9-7.3) with high W-HR, 6.8 (3.3-13.9) with high triceps skinfold thickness, 8 (4.1-15.7) with high subscapular skinfold thickness, and 10.1 (5-20.5) with high Sigma 4SF. In step-wise multiple logistic regression analysis, %BF [OR (95% CI): 3.2 (1.4-7.8)] and Sigma 4SF [OR (95% CI): 4.5 (1.8-11.3)] were independent predictors of hyperinsulinemia, similar to insulin resistance assessed by HOMA (homeostatic model of assessment) in the study.

CONCLUSION

A high prevalence of insulin resistance in postpubertal urban Asian Indian children was associated with excess body fat, abdominal adiposity, and excess truncal subcutaneous fat. Primary prevention strategies for coronary heart disease and diabetes mellitus in Asian Indians should focus on the abnormal body composition profile in childhood.

Decreased regulatory T-cells and CD4(+) /CD8(+) ratio correlate with disease onset and progression in patients with generalized vitiligo

The aim of present study was to evaluate CD4(+) /CD8(+) ratio and CD4(+) CD25(hi) FoxP3(+) Tregs in GV patients with reference to their effect on disease onset and progression. Flow cytometry was used for determination of CD4(+) /CD8(+) ratio and Tregs in 82 patients and 50 controls. CD8(+) T-cell counts were significantly higher in GV patients as compared with controls (p = 0.003). Active GV patients showed higher CD8(+) T-cell counts compared with stable GV patients (p = 0.001). The CD4(+) /CD8(+) ratio decreased significantly in patients as compared with controls (p = 0.001). Moreover, the ratio in active GV patients significantly lowered as compared with stable GV patients (p = 0.002). Significant decrease in Treg cell percentage and counts in GV patients was observed compared with controls (p = 0.009, p = 0.008) with significant reduction in FoxP3 expression (p = 0.024). Treg cell percentage and counts were significantly decreased in active GV patients compared with stable GV patients (p = 0.007, p = 0.002). Our results suggest that an imbalance of CD4(+) /CD8(+) ratio and natural Tregs in frequency and function might be involved in the T-cell mediated pathogenesis of GV and its progression.

Induction of regulatory T cells: A role for probiotics and prebiotics to suppress autoimmunity

Regulatory T cells (Tregs) are comprised of a heterogeneous population of cells that play a vital role in suppressing inflammation and maintaining immune tolerance. Given the crucial role of Tregs in maintaining immune homeostasis, it is probably not surprising that many microbial species and their metabolites have the potential to induce Tregs. There is now great interest in the therapeutic potential of probiotics and prebiotics based strategies for a range of autoimmune disorders. This review will summarise recent findings concerning the role of probiotics and prebiotics in induction of Tregs to ameliorate the autoimmune conditions. In addition, the article is focused to explain the different mechanisms of Treg induction and function by these probiotics and prebiotics, based on the available studies till date. The article further proposes that induction of Tregs by probiotics and prebiotics could lead to the development of new therapeutic approach towards curbing the autoimmune response and as an alternative to detrimental immunosuppressive drugs.

Large-diameter balloon dilation after endoscopic sphincterotomy for removal of difficult bile duct stones

BACKGROUND AND STUDY AIMS

Endoscopic sphincterotomy followed by extraction using a Dormia basket or an extraction balloon catheter is the procedure that is generally used for the removal of bile duct stones. This is not successful in all patients, however, and some stones have to be extracted using lithotripsy devices. In an attempt to avoid mechanical lithotripsy, we used large-diameter balloons after sphincterotomy for removing stones that could not be extracted using the conventional methods.

PATIENTS AND METHODS

In this retrospective pilot study, large-diameter (15-mm, 18-mm, or 20-mm maximum sizes) balloon dilation of the sphincterotomy site was performed in 50 patients in whom bile duct stones could not be removed by endoscopic sphincterotomy and Dormia basket or balloon catheter extraction.

RESULTS

The stones varied in size from < 15 mm to 25 mm. Common bile duct stones could be removed in all the patients using the large-diameter balloon technique. A Dormia basket or an extraction balloon catheter was required for removal of stones in 29 patients (58 %); and mechanical lithotripsy was required in five patients (10 %). Minor oozing of blood was seen in 16 patients (32 %), but the ooze stopped spontaneously during the endoscopy. Melena occurred in two patients and major bleeding requiring surgery occurred in one patient. Mild acute pancreatitis that resolved with conservative management occurred in four patients (8 %). There were no perforations and no deaths.

CONCLUSIONS

Large-diameter balloon dilation of the sphincterotomy site is an effective procedure for removal of bile duct stones that cannot be extracted by endoscopic sphincterotomy and conventional extraction devices. Mechanical lithotripsy could be avoided in the majority of these patients using this approach.

Regulatory T cells in vitiligo: Implications for pathogenesis and therapeutics

Vitiligo is a hypomelanotic autoimmune skin disease arising from a breakdown in immunological self-tolerance, which leads to aberrant immune responses against melanocytes. Regulatory T cells (Tregs) are crucial to the development of self-tolerance and so are major foci in the study of autoimmune pathogenesis of vitiligo. This review will summarise recent findings concerning the role of Tregs in the pathogenesis of vitiligo. In addition, as antigen-specific Tregs are a potential route for the reinstatement of immune tolerance, new strategies that expand or induce de novo generation of Tregs and which are currently being investigated as therapies for other autoimmune diseases, will be discussed. These approaches will highlight the opportunities for Treg cell-based therapeutics in vitiligo.

Prevalence and factors influencing hemorrhoids, anorectal varices, and colopathy in patients with portal hypertension

BACKGROUND AND STUDY AIMS

Little is known about the colon in patients with portal hypertension. The present study was carried out in order to assess the prevalence of, and factors influencing, hemorrhoids, anorectal varices, and colopathy in these patients.

PATIENTS AND METHODS

Seventy patients with cirrhosis and portal hypertension, and seventy controls, were prospectively studied. Full-length colonoscopy was carried out in all cases, and the presence of hemorrhoids, anorectal varices, and colopathy was noted.

RESULTS

Hemorrhoids and anorectal varices were seen in 36% and 40% of patients, compared to 40% and 0% in the controls. The difference was statistically significant only for anorectal varices (p < 0.001). Neither hemorrhoids nor anorectal varices were associated with the Child's grade of cirrhosis, the grade of esophageal varices, the presence of gastric varices, portal hypertensive gastropathy, or whether or not patients received sclerotherapy. Nor were they associated with each other. Colopathy was seen in 48.5% of the patients and 3% of the controls (p < 0.001). It was seen more frequently in patients with large esophageal varices compared to those with small varices (87% vs. 28.5%; p < 0.001), and more often in those with gastric varices than those without (71% vs. 28.5%; p < 0.001). It had no association with the severity of liver disease, the presence of hemorrhoids, portal hypertensive gastropathy, or whether or not patients received sclerotherapy.

CONCLUSIONS

It is concluded that the prevalence of hemorrhoids is not increased in patients with portal hypertension. However, the prevalence of anorectal varices and colopathy is higher in these patients. Portal colopathy occurs more commonly in patients with large esophageal varices, those with gastric varices, and those who do not have anorectal varices.

Colonic tuberculosis: clinical features, endoscopic appearance and management

BACKGROUND

Although rare in the West, colonic tuberculosis is not an uncommon disease in developing countries. However, the clinical manifestations and radiological appearance of the disease are non-specific. In recent years, colonoscopy has been found to be very useful in diagnosing patients with colonic tuberculosis.

METHODS

Clinical features, colonoscopic findings, histology and response to treatment were recorded in 50 patients with colonic tuberculosis.

RESULTS

Abdominal pain, fever, anorexia, weight loss and diarrhoea were the common symptoms. The colonoscopic features consisted of ulcers (92%), nodules (88%), deformed caecum and ileocecal valve (42%), strictures (25%), multiple fibrous bands (8%) and polypoid lesions (6%). Segmental tuberculosis and lesions simulating carcinoma were seen in 22 and 16% of patients, respectively. Histological examination of the colonic biopsy specimens showed well-formed, non-caseating granulomas in 18%, collection of loosely arranged epithelioid cells in 40% and chronic non-specific inflammatory changes in 42% of the patients. Six patients needed surgical intervention. The other 44 patients responded well to anti-tuberculous therapy and became asymptomatic.

CONCLUSIONS

It is concluded that colonoscopy is a useful method for diagnosing colonic tuberculosis. It is suggested that if the clinical picture and colonoscopic appearance are suggestive of tuberculosis and target biopsies reveal non-caseating granulomas, a collection of loosely arranged epithelioid cells, or even non-specific changes, then a therapeutic trial of anti-tuberculous drugs should be given and continued if there is clinical improvement.

Increased Tumor Necrosis Factor (TNF)-α and its promoter polymorphisms correlate with disease progression and higher susceptibility towards vitiligo

Tumor Necrosis Factor (TNF)-α, is a paracrine inhibitor of melanocytes, which plays a critical role in the pathogenesis of several autoimmune diseases including vitiligo, as abnormal immune responses have frequently been observed in vitiligo patients. Moreover, vitiligo patients show higher lesion levels of TNF-α. Genetic polymorphisms in the promoter region of TNF-α are involved in the regulation of its expression. The present study explores TNF-α promoter polymorphisms and correlates them with TNF-α transcript and protein levels in vitiligo patients and controls of Gujarat along with its effect on disease onset and progression. PCR-RFLP technique was used for genotyping of these polymorphisms in 977 vitiligo patients and 990 controls. TNF-α transcript and protein levels were measured by Real time PCR and ELISA respectively. The genotype and allele frequencies for the investigated polymorphisms were significantly associated with vitiligo patients. The study revealed significant increase in TNF-α transcript and protein levels in vitiligo patients compared to controls. In particular, haplotypes: AATCC, AACCT, AGTCT, GATCT, GATCC and AGCCT were found to increase the TNF-α levels in vitiligo patients. Analysis of TNF-α levels based on the gender and disease progression suggests that female patients and patients with active vitiligo had higher levels of TNF-α. Also, the TNF-α levels were high in patients with generalized vitiligo as compared to localized vitiligo. Age of onset analysis of the disease suggests that the haplotypes: AACAT, AACCT, AATCC and AATCT had a profound effect in the early onset of the disease. Moreover, the analysis suggests that female patients had an early onset of vitiligo. Overall, our results suggest that TNF-α promoter polymorphisms may be genetic risk factors for susceptibility and progression of the disease. The up-regulation of TNF-α transcript and protein levels in individuals with susceptible haplotypes advocates the crucial role of TNF-α in autoimmune pathogenesis of vitiligo.

Histomorphometric study of portal hypertensive enteropathy

Histopathologic features of duodenal and jejunal mucosal biopsy specimens obtained from 58 patients with portal hypertension and 30 healthy volunteers were studied. Dilated mucosal vessels with thickened walls were seen in duodenal and jejunal biopsy specimens from 39 (67%) and 41 (71%) of the patients, respectively, compared with corresponding biopsy specimens from 8 (27%) and 6 (2%) of the control subjects. The difference between the two groups was statistically significant. Other important histologic features in the patient group included edema of the lamina propria, fibromuscular proliferation, a decreased villous/crypt ratio, and thickened muscularis mucosae. The mean +/- SD thickness of capillary wall and diameter were significantly more in the patient group compared with those in the control subjects. We conclude that thick-walled dilated vessels along with edema of the lamina propria, fibromuscular proliferation, a decreased villous/crypt ratio, and thickened muscularis mucosae form a characteristic picture of portal hypertensive enteropathy. These changes seem to be a part of the changes seen in the gastrointestinal tract of patients with portal hypertension without any meaningful clinical implication except the increased chance of occult gastrointestinal blood loss.

Pancreaticobiliary ductal union

The main pancreatic duct and the common bile duct open into the second part of the duodenum alone or after joining as a common channel. A common channel of greater than 15 mm (an anomalous pancreaticobiliary duct) is associated with congenital cystic dilatation of the common bile duct and carcinoma of the gall bladder. Even a long common channel (greater than or equal to 8 mm) is associated with a higher frequency of carcinoma of the gall bladder. Gall stones smaller than the common channel and a long common channel predispose to gall stone induced acute pancreatitis. Separate openings for the two ductal systems predisposes to development of gall stones and alcohol induced chronic pancreatitis. The role of ductal union has also been investigated in primary sclerosing cholangitis and biliary atresia.

Interleukin-4 genetic variants correlate with its transcript and protein levels in patients with vitiligo

BACKGROUND

Vitiligo is an acquired pigmentary disorder resulting from loss of melanocytes. Interleukin (IL)-4 has been shown to stimulate B-cell proliferation, to regulate immunoglobulin class switching (IgG1 and IgE) and to promote T-cell development. Polymorphisms in the IL4 gene are known to increase its expression, thereby implicating its role in vitiligo susceptibility.

OBJECTIVES

To explore intron 3 VNTR (IVS3) and -590 C/T (rs2243250) promoter polymorphisms in the IL4 gene and to correlate them with the IL4 transcript, serum IL-4 and IgE levels to achieve genotype-phenotype correlation in patients with vitiligo from Gujarat. A replication study was done in a North Indian population.

METHODS

The case-control study was performed to investigate these polymorphisms in 505 patients and 744 controls in Gujarat, and 596 patients and 397 controls in North India by polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism analysis. IL4 transcript levels were monitored by real-time PCR. Serum IL-4 and IgE levels were measured by enzyme-linked immunosorbent assay and electrochemiluminescence immunoassay, respectively.

RESULTS

The genotype frequencies differed significantly between patients with generalized vitiligo and controls for both the polymorphisms in both populations. Allele frequencies significantly differed between patients with generalized vitiligo and controls for both the polymorphisms in the population from Gujarat. Interestingly, genotype and allele frequencies for -590 C/T single nucleotide polymorphism were significantly different between patients with localized vitiligo and controls in both the populations. The study revealed significantly increased IL4 mRNA, serum IL-4 and IgE levels in patients from Gujarat. Age of onset analysis of disease in patients suggested that the TTR2R2, TTR1R2 and CTR2R2 haplotypes had a profound effect in the early onset of the disease.

CONCLUSIONS

Our results suggest that these polymorphisms of the IL4 gene may be genetic risk factors for susceptibility towards vitiligo and the upregulation of the IL4 transcript, protein and IgE levels in individuals with susceptible haplotypes reveal the crucial role of IL-4 in the pathogenesis of vitiligo.

Association of neuropeptide Y (NPY), interleukin-1B (IL1B) genetic variants and correlation of IL1B transcript levels with vitiligo susceptibility

BACKGROUND

Vitiligo is a depigmenting disorder resulting from loss of functional melanocytes in the skin. NPY plays an important role in induction of immune response by acting on a variety of immune cells. NPY synthesis and release is governed by IL1B. Moreover, genetic variability in IL1B is reported to be associated with elevated NPY levels.

OBJECTIVES

Aim of the present study was to explore NPY promoter -399T/C (rs16147) and exon2 +1128T/C (rs16139) polymorphisms as well as IL1B promoter -511C/T (rs16944) polymorphism and to correlate IL1B transcript levels with vitiligo.

METHODS

PCR-RFLP method was used to genotype NPY -399T/C SNP in 454 patients and 1226 controls; +1128T/C SNP in 575 patients and 1279 controls and IL1B -511C/T SNP in 448 patients and 785 controls from Gujarat. IL1B transcript levels in blood were also assessed in 105 controls and 95 patients using real-time PCR.

RESULTS

Genotype and allele frequencies for NPY -399T/C, +1128T/C and IL1B -511C/T SNPs differed significantly (p<0.0001, p<0.0001; p = 0.0161, p = 0.0035 and p<0.0001, p<0.0001) between patients and controls. 'TC' haplotype containing minor alleles of NPY polymorphisms was significantly higher in patients and increased the risk of vitiligo by 2.3 fold (p<0.0001). Transcript levels of IL1B were significantly higher, in patients compared to controls (p = 0.0029), in patients with active than stable vitiligo (p = 0.015), also in female patients than male patients (p = 0.026). Genotype-phenotype correlation showed moderate association of IL1B -511C/T polymorphism with higher IL1B transcript levels. Trend analysis revealed significant difference between patients and controls for IL1B transcript levels with respect to different genotypes.

CONCLUSION

Our results suggest that NPY -399T/C, +1128T/C and IL1B -511C/T polymorphisms are associated with vitiligo and IL1B -511C/T SNP influences its transcript levels leading to increased risk for vitiligo in Gujarat population. Up-regulation of IL1B transcript in patients advocates its possible role in autoimmune pathogenesis of vitiligo.

HLA alleles and amino-acid signatures of the peptide-binding pockets of HLA molecules in vitiligo

Vitiligo is a depigmenting disorder of the skin that is characterized by the loss of functional melanocytes from the lesional sites. Although the exact etiology is not understood, autoimmunity is thought to be a crucial deterministic factor. A recurring theme of several autoimmune disorders is the aberrant presentation of self-antigens to the immune system, which triggers downstream perturbations. Here we examine the role of alleles of HLA class I and class II loci to delineate vitiligo manifestation in two distinct populations. Our studies have identified three specific alleles, HLA-A*33:01, HLA-B*44:03, and HLA-DRB1*07:01, to be significantly increased in vitiligo patients as compared with controls in both the initial study on North Indians (N=1,404) and the replication study in Gujarat (N=355) cases, establishing their positive association with vitiligo. Both generalized and localized vitiligo have the same predisposing major histocompatibility complex alleles, i.e., B*44:03 and DRB1*07:01, in both the populations studied, beside the differences in the frequencies of other alleles, suggesting that localized vitiligo too may be an autoimmune disorder. Significant differences in the amino-acid signatures of the peptide-binding pockets of HLA-A and HLA-B α-chain and HLA-DR β-chain were observed between vitiligo patients and unaffected controls.

Role of oxidative stress and autoimmunity in onset and progression of vitiligo

Vitiligo is an acquired depigmentation disorder characterized by the loss of functional melanocytes from the epidermis. Two major theories of vitiligo pathogenesis include autoimmunity and oxidative stress-mediated toxicity in melanocytes. The present study aimed to evaluate both the hypotheses in vitiligo patients and to investigate their role in the disease onset and progression. Antimelanocyte antibody levels and lipid peroxidation (LPO) levels were evaluated in 427 patients and 440 controls; antithyroid peroxidase (TPO) antibody levels were estimated in 102 patients and 72 controls. Patients showed a significant increase in LPO and antimelanocyte antibody levels compared to controls. Antimelanocyte antibody and LPO levels were higher in active vitiligo compared to stable. Only 9.8% of patients showed the presence of anti-TPO antibodies in their circulation. Oxidative stress may be the initial triggering event to precipitate vitiligo in Gujarat population, which is exacerbated by contributing autoimmune factors together with oxidative stress.

Involvement of interferon-gamma genetic variants and intercellular adhesion molecule-1 in onset and progression of generalized vitiligo

Interferon-gamma (IFN-γ) is a paracrine inhibitor of melanocytes and genetic variability due to intron 1 polymorphisms in IFNG has been reported to be associated with increased risk for several autoimmune diseases. The aim of present study was to determine whether intron 1 +874A/T (rs2430561) and CA microsatellite (rs3138557) polymorphisms in IFNG are associated with generalized vitiligo (GV) susceptibility and expression of IFNG and intercellular adhesion molecule-1 (ICAM1) affects the disease onset and progression. Here we report that IFNG CA microsatellite but not +874A/T may be a genetic risk factor for GV; however, +874T allele plays a crucial role in increased expression of IFNG mRNA and protein levels which could affect the onset and progression of the disease. Active GV patients showed increased IFNG levels compared to stable GV patients. The genotype-phenotype analysis revealed that IFNG expression levels were higher in patients with +874 TT genotypes and 12 CA repeats. Patients with the early age of onset showed higher IFNG expression and female GV patients showed higher IFNG and ICAM1 expression implicating gender biasness and involvement of IFN-γ in early onset of the disease. Moreover, the increased IFN-γ levels in patients lead to increased ICAM1 expression, which could be a probable link between cytokines and T-cell involvement in pathogenesis of GV.

Endoscopic and histologic appearance of the gastric mucosa in patients with portal hypertension

To assess reliability of the endoscopic and histologic appearance of the gastric mucosa for diagnosing portal hypertension, 50 patients with portal hypertension and 1323 controls were studied. Endoscopic evidence of mild gastritis was seen more frequently in patients with portal hypertension than in the control group (42% vs. 13.1%, p less than 0.001). The mosaic sign was also seen more frequently in patients with portal hypertension compared with controls (14% vs. 0.9%, p less than 0.001). However, the mosaic sign was found to be nonspecific, and the sensitivity for diagnosis of portal hypertension was only 14%. Biopsy specimens from the stomach of all patients with portal hypertension and 100 controls with a normal endoscopic appearance revealed mucosal vascular congestion in 72% of patients with portal hypertension compared with 59% of controls (NS). There was no correlation between endoscopic and histologic evidence of congestive gastropathy. Similarly, there was no correlation between the severity of mucosal vascular congestion and the degree of inflammatory changes observed in the biopsy specimens; both in the control (r = 0.1) and in patients with portal hypertension (r = 0.14). It is concluded that endoscopic and histologic features of the gastric mucosa in patients with portal hypertension are of low sensitivity and nonspecific and cannot be used to diagnose portal hypertension.

Involvement of superoxide dismutase isoenzymes and their genetic variants in progression of and higher susceptibility to vitiligo

Oxidative stress has been implicated as the initial triggering event in vitiligo pathogenesis leading to melanocyte destruction. Here, we report a significant increase in oxidative stress in vitiligo patients as evidenced by high lipid peroxidation levels suggesting an imbalance in the antioxidant enzyme system as reported in our previous studies. This study examined the role of the enzymatic antioxidant SOD, which converts the pro-oxidant superoxide into H2O2, in vitiligo pathogenesis. The activity of three isoforms of SOD, i.e., SOD1, SOD2, and SOD3, was significantly higher in vitiligo patients. To identify the underlying mechanism for the increase in activities of SOD isoforms, we explored the SOD1, SOD2, and SOD3 genes for their genetic variations and transcript levels. The SOD2 Thr58Ile (rs35289490) and Leu84Phe (rs11575993) polymorphisms were significantly associated with vitiligo patients, and the Val16Ala (rs4880) polymorphism was associated with active vitiligo patients. Interestingly, SOD2 activity was contributed by these polymorphisms along with its increase in transcript levels in patients. SOD3 activity was associated with the Arg213Gly (rs8192291) polymorphism. The SOD3 transcript levels were also increased in patients, which might contribute to the increased SOD3 activity. However, we could not establish the genotype-phenotype correlation for SOD1 as we could not detect any novel or reported SNPs in SOD1. In addition, both transcript and protein levels of SOD1 were unchanged between patients and controls, though SOD1 activity was increased in patients. Activities of SOD isoforms also correlated with progression of the disease as the activity was higher in active cases of vitiligo compared to stable cases. Here, we report that SOD2 and SOD3 polymorphisms may be genetic risk factors for susceptibility and progression of vitiligo and hence the genetic makeup of an individual may form a basis for the effective treatment of the disease. Overall, our results suggest that increased activity of SOD isoforms under the influence of genetic factors may lead to accumulation of H2O2 in cytoplasmic, mitochondrial, and extracellular compartments resulting in oxidative damage to the melanocytes.

Diagnosing ascites: value of ascitic fluid total protein, albumin, cholesterol, their ratios, serum-ascites albumin and cholesterol gradient

Ascitic fluid total protein, albumin, cholesterol, their ascites/serum ratios, serum-ascites albumin and cholesterol gradients were measured for their ability to differentiate cirrhotic, malignant and tuberculous ascites in 76 patients. The mean +/- s.d. ascitic fluid total protein, albumin, cholesterol, their respective ascitic fluid/serum ratios in cirrhotic ascites were lower than malignant and tuberculous groups (P < 0.001 for each). The difference between malignant and tuberculous groups was significant for ascitic fluid/serum total protein (P < 0.05) and ascitic fluid/serum albumin (P < 0.01) only. Mean serum-ascites albumin gradient in cirrhotics was higher than in the malignant and tuberculous groups (P < 0.001 for each). The difference between malignant and tuberculous groups was significant (P < 0.01). Mean +/- s.d. serum-ascites cholesterol gradient in cirrhotics was higher than that in malignant and tuberculous groups (P < 0.001 for each). The difference between malignant and tuberculous groups was also significant (P < 0.01). Both serum/ascitic fluid total protein less than 0.5 and ascitic fluid cholesterol less than 55 mg/dL had 94% diagnostic accuracy for differentiating cirrhotic from malignant and tuberculous differentiating cirrhotic from malignant and tuberculous ascites. Serum ascitic fluid albumin gradient greater than 1.1 g/dL, ascitic fluid/serum albumin less than 0.65 and ascitic fluid albumin less than 2 g/dL had diagnostic accuracy of 92, 92 and 91%, respectively. Ascitic fluid total protein had diagnostic accuracy of 88%. None of the tests was able to differentiate between malignant and tuberculous ascites. Measurement of ascitic fluid cholesterol concentration is a simple method of differentiating cirrhotic from non-cirrhotic ascites.

Association of NLRP1 genetic variants and mRNA overexpression with generalized vitiligo and disease activity in a Gujarat population

BACKGROUND

It has been suggested that NLRP1 is involved in susceptibility to a wide range of autoimmune diseases including generalized vitiligo (GV). Genetic polymorphisms in the gene encoding NLRP1 (previously known as NALP1) have previously been shown to be associated with GV and there is speculation about their involvement in the regulation of NLRP1 expression.

OBJECTIVES

To explore NLRP1 polymorphisms and investigate their association with NLRP1 mRNA expression and disease activity in patients with GV.

METHODS

Polymerase chain reaction (PCR)-restriction fragment length polymorphism and TaqMan single nucleotide polymorphism (SNP) genotyping techniques were used to genotype NLRP1 A/G (rs2670660), T/C (rs6502867) and A/T (rs12150220) polymorphisms in 537 patients with GV and 645 controls in Gujarat. NLRP1 mRNA levels were measured in the whole blood of 122 patients with GV and 175 controls using real-time PCR.

RESULTS

The NLRP1 rs2670660 and rs6502867 polymorphisms were found to be in significant association with GV, minor alleles of these SNPs being prevalent in active cases of GV. The rs12150220 polymorphism was found have a marginal association with GV. The frequency of susceptible haplotype 'GCT' was significantly higher in patients with GV and increased the risk of vitiligo twofold. A significant increase in NLRP1 mRNA expression was observed in patients with GV and patients with active GV. NLRP1 mRNA expression was increased in patients with GV with the susceptible GG (rs2670660) and CC (rs6502867) genotypes. Patients with the susceptible GG (rs2670660) and CC (rs6502867) genotypes had early age of onset of GV. Moreover, patients in the age at onset group of 1-20 years showed increased expression of NLRP1 mRNA compared with the older age groups. Female patients showed a significant increase in NLRP1 mRNA and early age at onset of GV compared with male patients.

CONCLUSIONS

Our results suggest that NLRP1 rs2670660 and rs6502867 polymorphisms may be genetic risk factors for susceptibility to and progression of GV. The upregulation of NLRP1 mRNA in patients with susceptible genotypes advocates the crucial role of NLRP1 in GV.

Altered expression of nuclear factor of activated T cells, forkhead box P3, and immune-suppressive genes in regulatory T cells of generalized vitiligo patients

The study was aimed to analyze expression of nuclear factor of activated T cells (NFATs), forkhead box P3 (FOXP3), and their associated genes (sCTLA4, flCTLA4, IL10, TGFB, IL2, IL4, CD25) in regulatory T cells (Tregs) of 48 generalized vitiligo (GV) patients and 45 unaffected controls. The transcripts of NFATC1 to NFATC4, FOXP3, IL10, flCTLA4 (p < .0001), NFAT5 (p = .0003), sCTLA4 (p = .001), and FOXP3 protein in Tregs and plasma IL-10 levels were reduced significantly (p < .0001) in GV Tregs compared to controls. The FOXP3 promoter polymorphisms [rs3761548(C > A), rs3761547(A > G), and rs2232365(A > G)] revealed significantly decreased FOXP3 protein levels in patients' Tregs with susceptible AA, GG, and GG genotypes (p < .0001, p = .028, p = .022, respectively). The active vitiligo Tregs showed reduced levels of NFATC3, NFATC4, NFAT5, FOXP3, TGFB, and flCTLA4 transcripts (p = .0005, p = .0003, p = .0002, p = .020, p < .0001, p = .006, respectively) and FOXP3 and TGF-β proteins (p = .0394 and p = .0013) compared to stable vitiligo. Early-onset patients (1-20 years) demonstrated decreased IL-10, sCTLA-4, flCTLA-4, TGFB, and FOXP3 transcripts and FOXP3 protein as compared to late-onset patients (41-60 years) (p = .001, p = .003, p = .009, p = .005, p = .038, p = .0226, respectively). Overall, our results for the first time suggest a likely role of NFATs and FOXP3 together with Treg immune-suppressive genes in GV pathogenesis and disease progression, warranting additional investigations.

Colonic changes in patients with cirrhosis and in patients with extrahepatic portal vein obstruction

BACKGROUND AND STUDY AIMS

Figures for the prevalence of anorectal varices and portal hypertensive colopathy have varied considerably in the available studies of patients with cirrhosis, and few studies have observed these changes in patients with extrahepatic portal vein obstruction (EHPVO). Our aim was to investigate the colonic changes, if any, in patients with EHPVO and to compare them with those seen in patients with cirrhosis of the liver.

PATIENTS AND METHODS

A total of 50 patients with cirrhosis and 35 patients with EHPVO, all of whom had a history of at least one episode of bleeding from esophageal varices, underwent both upper gastrointestinal endoscopy and colonoscopy.

RESULTS

Anorectal varices were seen more commonly in patients with EHPVO than in patients with cirrhosis (63 % vs. 38 %, P < 0.03). Of the patients with anorectal varices, large anorectal varices were also more common in patients with EHPVO than in patients with cirrhosis (73 % vs. 32 %, P < 0.01). Colopathy was noted in 40 % of patients with EHPVO and in 62 % of patients with cirrhosis (P < 0.05). Of the patients with EHPVO, colopathy was noted in 27 % of patients who also had anorectal varices and in 61.5 % of patients without anorectal varices (P < 0.05). Similarly, patients with both cirrhosis and anorectal varices were found to have a lower prevalence of colopathy than cirrhotic patients without anorectal varices (42 % vs. 74 %, P < 0.03).

CONCLUSIONS

Anorectal varices are more common in patients with EHPVO, while portal hypertensive colopathy is more common in patients with cirrhosis. Large anorectal varices are also more common in patients with EHPVO than in patients with cirrhosis and there is an inverse relationship between anorectal varices and colopathy in both cirrhotic patients and patients with EHPVO.

A prospective randomized trial comparing repeated endoscopic sclerotherapy and propranolol in decompensated (Child class B and C) cirrhotic patients

A prospective randomized study was conducted to compare the efficacy of long-term endoscopic sclerotherapy vs. propranolol in Child class B and C patients with variceal bleeds within the 30 days before the study. Forty-five and 46 patients were randomized to receive sclerotherapy and propranolol, respectively, after preentry stratification for Child scores. Sclerotherapy was administered with 1% polidocanol at 10-day intervals until obliteration of varices was achieved. Propranolol was administered to achieve a reduction in resting pulse rate of 25%. Rebleeding occurred in 19 patients undergoing sclerotherapy and in 31 receiving propranolol (p less than 0.05). The number of episodes of rebleeding was higher (p less than 0.05) in the propranolol group (n = 64) than in the sclerotherapy group (n = 35). The mean bleeding risk factor, number of hospitalizations for rebleeding and blood transfusion requirement were also significantly higher in the propranolol-treated patients. The median bleed-free period was more than 36 mo in the sclerotherapy group and 2.5 mo in the propranolol group (p less than 0.01). The median survival time was significantly longer in the sclerotherapy group (greater than 36 mo) than in the propranolol group (greater than 24 mo). We conclude that in decompensated cirrhotic patients, long-term endoscopic sclerotherapy is superior to propranolol in preventing rebleeding and improving survival.

Decreased suppression of CD8+ and CD4+ T cells by peripheral regulatory T cells in generalized vitiligo due to reduced NFATC1 and FOXP3 proteins

Regulatory T cells (Tregs) are involved in the suppression of activated T cells in generalized vitiligo (GV). The study was aimed to investigate Tregs functional defects in Treg:CD8⁺ and Treg:CD4⁺ T cells' co-culture systems of 55 GV patients and 45 controls. CD8⁺ and CD4⁺ T-cell proliferation was assessed by BrdU assay; production of IL-10, TGF-β and IFN-γ cytokines was assessed by ELISA; and FOXP3, CD25, NFATC1 and CD44 proteins were measured by flow cytometry. Generalized vitiligo patients showed reduced suppression of CD8⁺ and CD4⁺ T cells (P = .0384, P = .0084), increased IFN-γ (P < .0001, P = .0019), decreased IL-10 and TGF-β (P < .0001) and decreased FOXP3, CD25 and NFATC1 proteins (P < .0001). Active vitiligo (AV) patients showed reduced suppression of CD8⁺ & CD4⁺ T cells (P = .006, P = .015), increased IFN-γ (P = .036, P = .045), decreased IL-10 (P = .009, P = .021), FOXP3 (P = .0244) and NFATC1 (P = .019). Severe GV (50%-75% VASI) patients showed reduced suppression of CD8⁺ and CD4⁺ T cells (P = .0003, P = .001), increased IFN-γ (P = .0029, P < .0001), decreased IL-10 (P = .0057, P = .0017), FOXP3 (P = .002) and NFATC1 (P = .0347). VASI score was positively correlated with the suppression of CD8⁺ and CD4⁺ T cells (P = .0006, P < .0001), IL-10 (P = .0096, P = .029), FOXP3 (P = .0008) and NFATC1 (P = .043), whereas it was negatively correlated with IFN-γ (P = .0029, P = .0017). Early age of onset patients' Tregs demonstrated decreased suppression of CD8⁺ and CD4⁺ T cells (P = .0156, P = .0074), decreased TGF-β (P = .0212, P = .0083) and NFATC1 (P = .0103). NFATC1 was positively correlated with FOXP3 in Tregs (P < .0001). Our results suggest impaired Tregs suppressive function in GV patients due to decreased NFATC1, FOXP3, CD25, IL-10 and TGF-β resulting into increased CD8⁺ and CD4⁺ T-cell proliferation and IFN-γ production. For the first time, decreased NFATC1 levels were correlated with decreased FOXP3, thereby altering Treg cell function in GV patients. Additionally, decreased Treg cell function also affected onset, activity and severity of GV.