UTILITY OF GOMORI METHENAMINE SILVER STAINS IN BRONCHOALVEOLAR LAVAGESPECIMENS

Bronchoalveolar lavage (BAL) with Gomori methenamine silver (GMS) stai n is commonly used to detect Pneumocystis carinii and fungal organisms as causes of infectious pulmonic disease in immunosuppressed patients . However, several reports have indicated that GMS stains are not any more sensitive than conventional cytologic stains in detecting Pneumoc ystis organisms in select patient populations, such as those with acqu ired immunodeficiency syndrome (AIDS). To examine the utility of GMS s tains in our laboratory, we retrospectively reviewed 243 BALs from 188 patients. Sensitivity of the GMS stain for Pneumocystis and for fungi detection was 100%. Sensitivity for Pneumocystis and for fungi detect ion by Papanicolaou stain alone was 79% and 88%, respectively; by Diff -Quik stain alone it was 68% and 88%, respectively; and by combined Pa panicolaou and Diff-Quik stains it was 79% and 100%, respectively. In four additional cases, fungi were detected by other methods (culture, biopsy) and not by BAL. The GMS stain result was correlated with a num ber of risk variables to determine which variables were associated wit h GMS positivity. Using stepwise logistic regression, Pneumocystis pos itivity by GMS stain correlated (P < 0.0001) only with the variable of history of AIDS or AIDS risk factors. Fungal organism positivity by G MS stain correlated (P = 0.02) only with the variable of history of BA L positivity for fungus. Cost savings analyses were performed, estimat ing the cost of the GMS stain at $45 (total cost of GMS in 243 BALs wa s $10,935). A maximum cost of $9,623 could have been saved by screenin g conventional stains before using GMS stains and by using GMS stains only in patients with the variables of history of AIDS or AIDS risk fa ctors and history of BAL positivity for fungus.