Objective. Lupus nephritis is one of the serious manifestations of systemic lupus erythematosus (SLE). The prevalence of kidney involvement in SLE patients range from 30-70%. Anti-Smith (Sm) antibodies are essential for diagnosis of SLE in active lupus nephritis, especially in anti-dsDNA-negative patients. Histological evidence of lupus nephritis is present in most SLE patients and prevalence of mesangial proliferative lupus nephritis (ISN/RPS class II) was 19%. We report a case of a girl with mesangial proliferative lupus nephritis who had anti-dsDNA-negative but anti-Sm-positive antibodies.
Case. A case of a 10-year-old girl (BW 26 kg, height 132 cm, BP 100/60 mmHg) was hospitalized at in-patient ward of Pediatric Nephrology Division in Wahidin Sudirohusodo Hospital with recurrent pain in multiple joint, butterfly-shaped rash , discoid maculae on her neck & both elbows, photosensitivity and alopecia. This patient was diagnosed with SLE based on 8 clinical and 1 immunological criteria of SLICC; including malar rash, discoid rash, arthritis, photosensitivity, alopecia, leukopenia (WBC count 1680/mm3), hemolytic anemia (fragmented cells in blood smear), renal involvement (proteinuria +2, no hematuria, BUN 30 mg/dL, serum creatinine 0,5 mg/dL, serum albumin 3.6 g/dL and eGFR 145 mL/min/1.73 m2) and strong positive for anti-Sm antibodies test (+3) with anti-dsDNA antibodies titer test 84,7 IU/ml (normal <100 IU/ml). Histopathological finding showed mesangial proliferative lupus nephritis (ISN/RPS class II). The patient was treated with 1 mg/kgBW oral prednisolone daily and her therapeutic response was good with clinical improvement and significant decrease of proteinuria (proteinuria +/- after 2 weeks).
Conclusion. A case of mesangial proliferative lupus nephritis (ISN/RPS class II) in a 10-year-old girl has been reported. The diagnosis was based on history taking, physical examination, laboratory finding and renal biopsy. The choice of therapy was corticosteroid and prognosis of this patient was dubia.