الفهرس 
Introduction and Aim of the workOnly 14 pages are availabe for public view
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Abstract
Psoriasis is a chronic, recurrent, immune-mediated inflammatory disease. It is characterized by epidermal hyperplasia, dilated and prominent blood vessels in the dermis, and an inflammatory infiltrate of leukocytes, predominantly in the dermis.
It affects 1-3% of the world population and characterized by well-demarcated erythematous plaques with adherent silvery scales. The most frequent areas of involvement include the elbows, knees, lower back, and buttocks but the disease can involve any cutaneous surface. The disease varies widely in severity and extent of involvement as some patients present with a few isolated plaques and others can have complete coverage of their body surface. Variations in the morphology of psoriasis have been classified into several clinical subtypes as plaque psoriasis, guttate psoriasis, erythrodermic psoriasis, psoriatic arthritis and pustular psoriasis. The pathogenesis is unknown but factors such as genetic factors, immunological factors and environmental factors were taken into account. Researchers focused their attention on oxidative stress, considering it an important factor in psoriasis pathogenesis and research in this field has been increasing during the last few years.
Oxidative stress is defined as disturbance in the balance between the production of reactive oxygen species (ROS) and antioxidant defense mechanisms. In psoriasis, generation of reactive oxygen species may play an important role in psoriatic process.
Glucose-6-phosphate dehydrogenase (G6PD) enzyme is the first & rate limiting step of hexose monophosphate pathway which protects the cells from oxidant injury.
G6PD is one of the main antioxidant enzymes in the body. The low erythrocyte levels of this enzyme have been shown to be a reliable indicator of oxidative stress.
The aim of this study was to measure erythrocyte levels of G6PD, one of the enzymatic indices of antioxidant status, in patients with mild and severe psoriasis to determine its possible role in the pathogenesis and progress of psoriasis. And if it can be used as a biochemical marker of oxidative stress in psoriasis.
This study was carried out at Dermatology, Andrology & STDs and Medical Biochemistry Departments, Faculty of Medicine, Menoufia University. It included 39 subjects: 26 patients with psoriasis & 13 age and gender matched healthy individuals as controls.
Patients were randomly recruited from outpatient clinics, of Dermatology, Andrology & STDs Department, Menoufia University Hospitals during the period between October 2017 and March 2018.
All patients were not on any topical or systemic therapy for at least 3 months. All studied cases were subjected to complete history taking as (personal history, present history, family history, history of drug intake, history of other dermatological autoimmune diseases, history of systemic diseases) and to general and dermatological examination including assessment of PASI score. Blood levels of G6PD & hemoglobin were estimated after taking an informed consent.
The results of this study revealed the following:
The mean age of mild psoriatic cases (group1) was (34.54±14.92 years) and that of the severe cases (group2) was (43.85±5.05 years) while in the control group (group3) it was (36.62±5.69 years). So, there was significant difference between group1 and 2 whereas non-significant difference existed between group 1 & 3 and group 2& 3.
There was non-significant difference between the three studied groups
regarding gender (P-value = 0.734).
The mean duration of illness of mild cases (group 1) was (2.77 ± 1.74 years) and that of the severe cases (group2) was (4.54 ± 1.76 years).
There was statistically significant difference between the two studied patient groups regarding PASI score as mean of PASI score of mild cases (group1) was (7.77 ± 1.09) whereas of severe cases (group2) was (32.85 ± 9.75).
Only 6 cases (23.1%) had positive family history of psoriasis.
Elbows and knees were the most common sites affected 25 cases (96.2%).
There was statistically significant difference between G6PD enzyme levels among the three groups (P-value<0.001), whereas there was non-significant statistical difference in Hb levels among the three groups, (P-value =0.949). Also, there was significant negative correlation between G6PD and each of disease duration and PASI score in psoriasis patients, whereas non-significant negative correlation existed with age.
To predict psoriasis patients from controls at cut off point of G6PD ≤ 10.9 U/g Hb the sensitivity was 92.31%, specificity was 84.62%, PPV of 92.3% and NPV of 84.6%.
To predict severe psoriasis from mild cases by using PASI score and G6PD. At cut off point of PASI score of > 9, the sensitivity was 100.0%, specificity was 100.0%, PPV of 100.0% and NPV of 100.0%. At cut off point of G6PD of ≤ 7.8 U/gHb, the sensitivity was 92.31%, specificity was 92.31%, PPV of 92.3% and NPV of 92.3%.