الفهرس | Only 14 pages are availabe for public view |
Abstract Alopecia areata is a common type of hair loss or alopecia in humans. The exact pathophysiology of AA is currently unknown. Mitochondria have retained their own genome; mtDNA that is essential for oxidative phosphorylation. Emerging evidence strongly suggests that the proportion of mutated mtDNA copies is not the only determinant of disease but that also the absolute copy number matters. This study aimed to study mitochondrial DNA copy number in patients with AA and healthy controls and to compare the results with the available clinical data. This is a case-control study that was performed at the Dermatology, Andrology, and STDs,Department of Clinical Biochemistry & Molecular Diagnostics, National Liver Institute. The study included 05 patients with AA who were collected consequently from the Outpatient Clinic of the Dermatology and Andrology, and STDs , Menoufia University Hospitals. Additional 50 age and sex matched normal healthy individuals were included as a control group. Cases were subjected to full history taking, clinical examination including detailed deramtologic clinical examination of scalp, nails and glabrous skin. Assessment of disease severity was done by SALT score. Cases were classified according to the Kavak’s classification into mild, moderate, and severe. Laboratory examination included DNA Extraction, PCR amplification and mtDNA quantification using the suitable kits according to the manufacturer instructions. Summary 70 In this study, cases were 43 (86 %) males and 7 (14%) females. Their age ranged from 20 to 45 years with 30.84± 8.06 years as X ±SD value. Control subjects were 42(84 %) males and 8 (16%) females .Their age ranged from 20 to 45 years with 30.4± 6.7 as X ±SD value. There were no significant differences between cases and controls regarding age and sex (p˃ 0.05 for both). Regarding clinical data of the studied cases, onset of the disease was sudden in 24 (48%) cases and was gradual in 26 (52%) cases. 17 (34%) cases had stationary course while 33 (66%) cases had progressive course. Duration of disease ranged from 1 to 24 months with 5.57± 5.60 months as X± SD. History of exposure to stressful events was positive in 31 (62%) cases and was negative in 19 (38%) cases. 12 (24%) cases were with positive family history of alopecia areata and 38 (76%) cases had negative family history of alopecia areata. Site of lesion was in scalp in all (100%) cases. SALT score ranged from 10 to 100 with 22.77± 34.18 as X± SD value. According to kavak’s classification; 25 (50%) cases had mild AA, 15 (30%) cases had moderate AA and 10 (20%) cases had severe AA. There was statistically significant increase in mitochondrial DNA copy number level in cases than controls (U= 14, p<0.001). There was non-significant relationship between mean expression level of mitochondrial DNA copy number and clinical data of the studied cases. There was significant positive correlation between mean expression level of mitochondrial DNA copy number and SALT score (r=0.622, p=0.001). Summary 71 With cut off value > 1.619; there was a significant validity of prediction (P-value < 0.001) of mitochondrial DNA copy number to diagnose cases (N=50) of AA from controls (N=50) with sensitivity and specificity of 96% and 98%, respectively. By using ROC curve analysis, mitochondrial DNA copy number expression can diagnose mild cases of AA from moderate cases with sensitivity and specificity of 93.3% and 94.2%, respectively when the cutoff point was > 1.36 and p value 0.007. By using ROC-curve analysis, mitochondrial DNA copy number expression can diagnose moderate cases of AA from severe cases with sensitivity and specificity 80% and 86.67%, respectively, when the cutoff point was > 2.94, with a statistically high significant p value (p<0.001). By using ROC-curve analysis, mitochondrial DNA copy number expression can diagnose mild cases of AA from severe with sensitivity and specificity of 80% and 88%, respectively, when the cutoff point was > 3.13, with a statistically high significant p value (p<0.001). |