RESUMO
Systemic Lupus Erythematosus [SLE] is an autoimmune rheumatic disease and glomerulonephritis is a challenging complication of SLE which is more frequent in children. Thymus and activation - regulated chemokine [TARC] is a hemostatic chemokine and TARC production is induced rapidly thus providing an important link between early innate immune responses and adaptive immunity. The aim of the present work was to measure serum TARC in SLE patients and correlate it with disease activity in patients with clinically evident lupus nephritis versus patients without lupus nephritis. This study was conducted on thirty patients [26 females and 4 males] with SLE, regularly attending the Pediatric Allergy and lmmunology Clinic Children's Hospital, Ain Shams University. Their ages ranged between 9-16 years [mean +/- SD = 13.6 +/- 2.68 years]. Lupus patients were categorized into two groups according to lupus nephritis [LN]: Group I a [with LN] and Group I b [without LN]. Results of the previous two groups were compared to a control group comprised of 40 [27 females and 13 males] age and sex matched apparently healthy subjects whose ages ranged between 10 and 16 years [mean + SD= 12.95 +/- 2.68 years]. All participants were subjected to full history taking, thorough clinical examination, urine analysis, assessment of ESR, creatinine, C3, ANA Abs, anti-dsDNA Abs and serum TARC. All SLE patients were seropositive for ANA. Serum TARC levels were statistically highly significantly [p=<0.001] elevated in all lupus patients, in Group Ia, in Group lb all respectively compared to controls and also in Group Ia versus Group lb. As regards indicators of LN, serum TARC showed statistically highly significant [p<0.001] elevated levels in patients with hematuria, edema, hypertension and anti-dsDNA positivity than in those with negative indicators of LN. Serum TARC showed statistically significant [p<0.05] positive correlation with ESR and SLEDAT score in all lupus patients, statistically highly significant [p=<0.001] positive correlation with ESR [in group I a], 24 hrs urinary proteins [in all lupus patients and group I b] and serum creatinine [in all lupus patients, group I a and group I b]. In conclusion, serum TARC levels were statistically significantly higher in all lupus patients versus healthy controls being statistically significantly higher in LN patients with versus lupus patients without nephritis. Also, serum TARC had significant positive correlation to SLEDAI score and ESR indicating its correlation with disease activity