Altered serum uric Acid level in lichen planus patients

Bilirubin as a new antioxidant in melasma

BACKGROUND

Oxidative stress and its role in the pathogenesis of cutaneous diseases have been widely investigated. However, there are few studies that have solely assessed the contribution of intracellular antioxidants in the etiopathology of melasma. Furthermore, there are convincing reports about antioxidant properties of bilirubin (Bil) and uric acid (UA) in some skin disorders but not melasma.

OBJECTIVE

This study aimed to determine serum levels of two major extracellular antioxidants (Bil and UA) levels in patients with melasma and their correlation with the severity and extent of the disease.

METHODS

In this case-control study, the serum levels of bilirubin and uric acid of 50 melasma patients were compared with 50 healthy controls. Moreover, the correlation of serum concentrations of these antioxidants with the extent and severity of the disease were assessed.

RESULTS

The serum concentration of Bil was significantly higher in the case group (p < 0.05). Furthermore, serum Bil level had a positive correlation with the extent of the melasma (correlation coefficient, +0.3; p < 0.05). No significant difference was found between the serum concentrations of UA between the study and control group. Neither Bil nor UA had a significant correlation with the severity of the disease.

CONCLUSION

Oxidative stress may play a major role in the etiopathology of melasma and bilirubin, as an antioxidant, could be involved in the process of oxidative stress.

Thiol-Disulfide Homeostasis in Skin Diseases

Oxidative stress represents the imbalance between oxidants and antioxidants and has been associated with a wide range of diseases. Thiols are the most important compounds in antioxidant defense. There is an equilibrium between thiols and their oxidized forms, disulfides, known as dynamic thiol-disulfide homeostasis (TDH). In 2014, Erel and Neselioglu developed a novel automated assay to measure thiol and disulfide levels. Subsequently, many researchers have used this simple, inexpensive and fast method for evaluating TDH in various disorders. We have reviewed the literature on the role of TDH in skin diseases. We identified 26 studies that evaluated TDH in inflammatory diseases (psoriasis, seborrheic dermatitis, atopic dermatitis, vitiligo, acne vulgaris and rosacea), allergic diseases (acute and chronic urticaria) and infectious diseases (warts, pityriasis rosea and tinea versicolor). The results are heterogeneous, but in most cases indicate changes in TDH that shifted toward disulfides or toward thiols, depending on the extent of oxidative damage.

Oxidative Stress in Cutaneous Lichen Planus-A Narrative Review

Lichen planus (LP) is a chronic, immune-mediated inflammatory skin condition that mainly affects the skin (cutaneous LP, CLP) and oral mucosa (oral LP, OLP). However, the mechanisms involved in the pathogenesis of the disease are not fully elucidated. Over time, several theories that could explain the appearance of LP lesions have been postulated. The key players in LP pathogenesis are the inflammatory infiltrate consisting of T cells and the proinflammatory cytokines. The cytokines stimulate the production of reactive oxygen species that induce cell apoptosis, a defining element encountered in LP. The lead inquiry triggered by this revolves around the role of oxidative stress in LP development. There are currently numerous studies showing the involvement of oxidative stress in OLP, but in terms of CLP, data are scarce. In this review, we analyze for the first time the currently existing studies on oxidative stress in CLP and summarize the results in order to assess the role of oxidative stress in skin lesions offering a fresher updated perspective.

Evaluation of serum uric acid levels in patients with rosacea

Rosacea is an inflammatory skin disease with a chronic course. Although the pathogenesis of rosacea is not completely understood, it is regarded as an inflammatory process. The aim of the present study was to evaluate uric acid (UA) levels in patients with rosacea and to detect the correlation of UA levels with disease activity. A total of 61 patients with rosacea and 64 sex- and age-matched controls were included in the study. Demographic characteristics, medical history, and dermatological examination of the patient and control groups were recorded. Concentrations of serum UA and C-reactive protein (CRP) were evaluated and compared in both groups. This study included 61 patients with rosacea (39 females, 22 males, median age = 30 years) and 64 age- and sex-matched controls. Metabolic syndrome was significantly more common in patients with rosacea than in the control group. Patients with rosacea had significantly higher body mass index (BMI) values compared with those of controls. Serum UA and CRP values were significantly higher in the rosacea group than values in the control group. There was no statistically significant correlation between serum UA level and clinical rosacea severity. This study suggests that rosacea is not only a skin-related disease but also an inflammatory disease that can be related to higher uric acid levels, BMI values, and metabolic syndrome. It may be recommended that clinicians pay careful attention to the clinical follow-up of these patients to avoid missed associated comorbidities.

Roles of serum uric acid, prolactin levels, and psychosocial factors in oral lichen planus

Free radicals play important roles in the mechanisms underlying lichen planus (LP). Uric acid (UA) is an important anti-oxidant in plasma. Prolactin (PRL) is an immunomodulatory hormone that may promote LP, as has been documented in other autoimmune disorders, such as systemic lupus erythematosus, rheumatoid arthritis, and psoriasis. PRL has multiple immune-stimulatory effects and promotes the development of such autoimmune disorders. Prolactin and uric acid may serve as biomarkers of disease activity in lichen planus. The aim of the present study was to evaluate the roles of depression, stress, and anxiety in LP, as well as serum levels of UA and PRL as potential biomarkers of disease activity and compare these findings with those of the control group. Thirty-nine patients clinically diagnosed with oral LP (study group) and 39 age- and sex-matched controls (control group) were selected in this study. Serum UA and PRL levels were measured. The Depression Anxiety Stress Scale-21 was used for psychometric evaluation of LP patients and controls. Serum UA level was found to be significantly higher in the control group as well as during the remission phase of disease in the study. There was no significant difference in serum PRL levels between cases and controls. Depression and stress scores were higher in the study group.

Ascorbic acid deficiency in patients with lichen planus

OBJECTIVES

Recent studies have highlighted the role of oxidative stress in the pathogenesis of lichen planus (LP). In the present study, the interest of the authors is focused on the investigation of ascorbic acid status in patients with LP and identification of parameters that might influence the level of this vitamin.

MATERIAL AND METHOD

We analyzed the level of urinary ascorbic acid (reflectometric method) in 77 patients with LP (cutaneous LP (CLP)-49 cases; oral LP (OLP)-28 cases) and 50 control subjects. The evaluation of all participants included clinical examination and laboratory and imaging tests.

RESULTS

Compared to the control group (19.82 mg/dl) the level of ascorbic acid was significantly lower both in patients with CLP (8.47 mg/dl, p = 0.001) and in those with OLP (8.04 mg/dl, p = 0.001). In patients with LP it was found that the deficiency of ascorbic acid increases with age (r = -0.318, p = 0.032). The urinary concentrations of ascorbic acid were significantly lower in patients with LP associated with infections compared to patients with LP without infections.

CONCLUSIONS

The urinary ascorbic acid level may be a useful parameter in identifying patients with LP who are at risk of developing viral or bacterial infections.

Physiological functions and pathogenic potential of uric acid: A review

Uric acid is synthesized mainly in the liver, intestines and the vascular endothelium as the end product of an exogenous pool of purines, and endogenously from damaged, dying and dead cells, whereby nucleic acids, adenine and guanine, are degraded into uric acid. Mentioning uric acid generates dread because it is the established etiological agent of the severe, acute and chronic inflammatory arthritis, gout and is implicated in the initiation and progress of the metabolic syndrome. Yet, uric acid is the predominant anti-oxidant molecule in plasma and is necessary and sufficient for induction of type 2 immune responses. These properties may explain its protective potential in neurological and infectious diseases, mainly schistosomiasis. The pivotal protective potential of uric acid against blood-borne pathogens and neurological and autoimmune diseases is yet to be established.

Assessment of Uric Acid Level in the Saliva of Patients with Oral Lichen Planus

OBJECTIVE

The aim of this study was to evaluate the level of uric acid (UA) in saliva, which is considered to be an antioxidant defense biomarker against oxidative stress in patients with oral lichen planus (OLP).

SUBJECTS AND METHODS

In this case-control study, 25 OLP patients were included. The reticular form of OLP was verified by a clinical examination with Wickham striae, and other types (erosive, atrophic, ulcerative) were confirmed by histopathological assessment. Thirty healthy individuals matched for age and gender were selected as the control group. In both groups, the Navazesh technique was used to collect the unstimulated saliva. Then, the amount of UA was measured using a Cobas Mira autoanalyzer with a wavelength of 546 nm. The Student t test was used to analyze the data assuming a significance level at <0.05.

RESULTS

Of the 25 patients, the most common type of OLP was erosive (n = 11, 44%), and the most common site of OLP was seen as bilateral in the buccal mucosa (n = 12, 48%). The mean level of salivary UA was significantly lower in the patients with OLP (2.10 ± 0.19 mg/dL) in comparison with the control group (4.80 ± 0.29 mg/dL; p < 0.001).

CONCLUSION

In this study, OLP was associated with a decrease in UA levels in the saliva. Salivary UA as a biomarker could be used for monitoring and treating OLP.

Serum uric acid levels during leprosy reaction episodes

Background. Leprosy reactions are acute inflammatory episodes that occur mainly in the multibacillary forms of the disease. The reactions are classified as type 1 (reverse reaction) or type 2 (erythema nodosum leprosum). Leprosy-associated oxidative stress has been widely demonstrated. Several recent studies have shown uric acid (UA) to have antioxidative effects under pathologic conditions. The objective of this study was to assess serum levels of UA in patients with leprosy reactions, with the aim of monitoring their levels before and after treatment, compared with levels in leprosy patients without reactions.

Methods. The study included patients aged 18–69 years assisted at a leprosy treatment reference center in the Central Region of Brazil. Patients who were pregnant; were using immunosuppressant drugs or immunobiologicals; or had an autoimmune disease, human immunodeficiency virus infection, acquired immune deficiency syndrome, or tuberculosis were excluded. Upon recruitment, all individuals were clinically assessed for skin lesions and neural or systemic impairment. Some patients had already completed treatment for leprosy, while others were still undergoing treatment or had initiated treatment after being admitted. The treatment of the reactional episode was started only after the initial evaluation. Laboratory assessments were performed upon admission (baseline) and at approximately 30 and 60 days (time points 1 and 2, respectively).

Results. A total of 123 leprosy patients were recruited between June 2012 and June 2015; among them, 56, 42, and 25 presented with type 1, type 2, and no reactions, respectively. Serum UA levels were significantly reduced in patients with type 2 leprosy reactions compared with patients in the control group and remained lower in the two subsequent assessments, after initiation of anti-reaction treatments, with similar values to those recorded before the treatment.

Discussion. The decreased serum UA levels in patients with type 2 leprosy reactions might be due to the consumption of UA to neutralize the enhanced production of oxygen- and nitrogen-reactive species that occurs during type 2 reactions. The maintenance of the reduced levels in the follow-up assessments may indicate persistence of oxidative stress in the initial post-treatment stages, despite improved clinical conditions. The results of this study suggest that serum UA may play an antioxidative role during type 2 leprosy reactions.