mRNA expression of MAGE-A3 gene in leukemia cells.

Leukemia-associated antigens such as proteins encoded by MAGE genes might provide tools for immunotherapy of leukemia. Positive and negative results of MAGE-A gene expression in hematological malignancies have been reported. This led us to study MAGE-A gene expression in human leukemias using RT-PCR. Among 115 leukemias from various subtypes, 14/34 (41.17%) AML were positive for one of the three genes analyzed (MAGE-A1 1/32; MAGE-A3 10/32; MAGE-B2 3/12). Expression was also detected in 23/76 (30.26%) B-cell ALL patients (MAGE-A1 2/53; MAGE-A3 20/53; MAGE-B2 1/32). One of these patients expressed both MAGE-A1 (weak signal) and -A3 (strong signal) genes. Other patient with CML were positive for MAGE-B2 (1/5, 20%). MAGE-A3 expression data were corroborated by real time RT-PCR through determination of MAGE-A3 transcript levels. We concluded that the MAGE-A3 gene is expressed at the mRNA level in a proportion of human leukemias.

Intermittent intravenous cyclophosphamide therapy for lupus nephritis.

We carried out a preliminary study to determine whether intermittent intravenous cyclophosphamide therapy could be safely and effectively used in the treatment of childhood lupus nephritis. Sixteen children (4 to 18 years of age) with lupus nephritis were treated with cyclophosphamide monthly for 6 months and then every 3 months. Eight children were treated because of corticosteroid-unresponsive active lupus nephritis, with a fall in their creatinine clearance to less than 100 ml/min/1.75 m2, and eight children were treated because of corticosteroid-dependent nephrotic syndrome or active lupus nephritis with unacceptable corticosteroid-induced side effects. Cyclophosphamide treatment was associated with significant improvement at 1 year in mean levels of hemoglobin (11.3 +/- 0.5 to 13.1 +/- 0.3 gm/dl), C3 (52 +/- 5.9 to 108 +/- 13.7 mg/dl), and C4 (7.6 +/- 0.9 to 15.9 +/- 2.2 mg/dl) (all p less than 0.005), despite a significant reduction in mean prednisone dosage (31 +/- 5 to 14 +/- 2 mg/day; p less than 0.005). There was a decrease in 24-hour urine protein excretion from 3121 +/- 913 to 1016 +/- 364 mg/24 hours (p less than 0.05). For children whose initial creatinine clearance was less than 100 ml/min/1.75 m2, creatinine clearance also improved significantly (57.5 +/- 11 to 121 +/- 24.5 ml/min/1.75 m2; p less than 0.05). The long-term safety of intravenous cyclophosphamide therapy and its long-term efficacy in comparison with prednisone alone remain to be established. In the interim, intravenous cyclophosphamide therapy should be reserved for children with severe, unacceptable corticosteroid side effects or with corticosteroid-resistant and potentially life-threatening disease.

Urinary citrate excretion in the diagnosis of distal renal tubular acidosis.

Since hypocitraturia in distal renal tubular acidosis, we screened the asymptomatic children in three families with familial dRTA, by comparing their 24-hour urine citrate excretion to values obtained in 45 normal children. Subsequent acid loading uncovered four new cases of dRTA suspected because of the finding of hypocitraturia. Because hypocitraturia probably contributes to nephrolithiasis/nephrocalcinosis and subsequent renal damage in dRTA, affected family members were treated with alkali (4 mEq/kg/day), which normalized urine citrate in three children; in a fourth child citrate excretion rose but was not normal. Measurement of urine citrate excretion was superior to other currently proposed screening tests for dRTA (first morning urine pH and sediment, urine concentration).