Djenkol bean as a cause of urolithiasis

An 8-year-old boy was admitted into the hospital with symptoms of anuria after consumption of 12 djenkol beans. Laparotomy showed a urethral calculus, size 2.0 x 0.4 cm, which was found to contain djenkolic acid 65 gm/100 gm stone with a small amount of protein, sodium, potassium and uric acid. This calculus contained no calcium, magnesium, phosphorus, ammonium salt, oxalate, carbonate, cystine and fibrin. The solubility of L-djenkolic acid in urine at 37 degrees C was found to be pH dependent, i.e., the higher the pH, the increase in solubility of djenkolic acid. D-pencillamine also showed similar effect, increasing the solubility of L-djenkolic acid in the urine at pH 5.7 in vitro. The cause and mechanism of formation of djenkolic acid crystals and calculi were discussed.