RESUMO
OBJECTIVE: Microcolumn tests are useful for serological investigations, although because of their high sensitivity, false-positive results might be expected, e.g. in hypergammaglobulinemia. The aim of this study was to evaluate these tests in multiple myeloma. METHODS: Pretransfusion testing was done in 80 patients with multiple myeloma using microcolumn and traditional tube tests. RESULTS: All sera were negative in microcolumn indirect antiglobulin test and enzyme test, positive in 58% of samples in the enzyme tube test. The microcolumn direct antiglobulin test was positive in about 40% of samples but never in the tube direct antiglobulin test. This was not due to the presence of autoantibodies but to nonspecific binding of immunoglobulins related to their concentration in sera. CONCLUSION: Microcolumn tests appeared to be useful for pretransfusion testing in multiple myeloma in spite of positive autocontrols.
