A modified radioimmunoassay for arylsulfatase A in human serum and urine

Strategy for effective inhibition of arylsulfatase/β-glucuronidase to prevent deconjugation of sulfate and glucuronide conjugates in wastewater during sample collection and storage

Arylsulfatase and β-glucuronidase are two important enzymes that are responsible for deconjugation of estrogen conjugates. It is important to keep estrogen conjugates intact during sample collection and storage, while the effective inhibition conditions for arylsulfatase and β-glucuronidase remain unknown. To elucidate these conditions, inhibition experiments were performed by adding several inhibitors or by introducing extreme pH conditions. This work confirms that arylsulfatase and β-glucuronidase can tolerate some extremes, including high concentrations of mercury dichloride, ethanol, and EDTA, while low pH (<3) or high pH (>11) can effectively inhibit their activities. The high tolerance of arylsulfatase and β-glucuronidase for mercury dichloride explains why estrogen conjugates in wastewater samples were deconjugated, even in the extremely unfavorable condition with a high concentration of mercury dichloride. Although low pH (<3) can effectively inhibit arylsulfatase/β-glucuronidase, deconjugation of sulfate conjugates by acid hydrolysis readily occurs; thus, a high pH of 11 is an appropriate storage condition for the effective inhibition of arylsulfatase/β-glucuronidase. This appropriate storage condition was confirmed and validated with diluted and sterilized activated sludge samples in which arylsulfatase/β-glucuronidase inhibition was effective for 48 h at room temperature and with a high pH of 11. The developed appropriate storage condition for effective inhibition of arylsulfatase/β-glucuronidase has wide application potential not only for estrogen conjugates but also for all conjugates of other organic micropollutants.

Arylsulfatase A in serum from patients with cancer of various organs

Arylsulfatase A was radioimmunoassayed in serum specimens of 96 healthy volunteers and 368 patients with histopathologically confirmed cancer of gastrointestinal tract, breast, lung, central nervous system, kidney and woman genital tract. Sensitivity, specificity and predictive value of the test were 43%, 82% and 90%, respectively, which means that a positive test is significant for diagnosis of cancer regardless of its localization. More detailed statistical analysis of the results indicates that determination of the serum concentration of arylsulfatase A might be helpful in the diagnosis of lung (59% sensitivity, 82% specificity) and central nervous system cancer (60% sensitivity, 82% specificity). Further studies should also be continued in respect to renal and women genital tract cancers for which the results of the test, although promising, are at present not conclusive due to the small numbers of examined cases. Particularly, determination of serum arylsulfatase A in case of endometrial cancer seems to be of diagnostic value. Arylsulfatase A concentration in serum with a lower than 40% sensitivity of the test cannot be considered as a valuable tumor indicator in the case of cancer of breast and gastrointestinal tract, although 80% predictive value of the test for the latter group of tumors is quite high and perhaps merits additional consideration.