Aplastic anemia and paroxysmal nocturnal hemoglobinuria: a follow-up study of the glycosylphosphatidylinositol-anchored proteins defect.

INTRODUCTION

Flow cytometry analysis of peripheral blood cells is a simple and reliable method for establishing the diagnosis of paroxysmal nocturnal hemoglobinuria. The behavior of the clone may vary; increasing or diminishing over time but prospective study of such variations have not been reported so far.

MATERIALS AND METHODS

We report herein the results of a prospective follow-up study of 25 patients. Our aims were twofold: first, to evaluate the behavior of the clone (using flow cytometry) over the time; and second, to evaluate if such variations could predict the occurrence of complications or could be used as a tool for monitoring the residual disease after bone marrow transplantation.

RESULTS

It was found that flow cytometry can be used to specifically follow the residual disease post allogeneic marrow transplantation in four patients, and that even without transplantation the defective clone can significantly decrease or even disappear (three patients).

CONCLUSION

We found that most of the patients did have significant change in the amount of affected cells during more than three years, and that an increased size of the clone poorly predicted the occurrence of complications.