111Indium-chloride bone marrow scintigraphy in aplastic anaemia

Bone marrow scintigraphy, using 111Indium-chloride, was performed in 24 patients with acquired aplastic anaemia to investigate: (1) a possible relationship between bone marrow scintigraphy and peripheral blood cell values, (2) a possible relationship between scintigraphy and histology of the bone marrow and (3) the ability to distinguish various aplastic anaemia subtypes with bone marrow scintigraphy. For this purpose a semi-quantitative scoring of scintigraphic results was used. Only a weak correlation was found between the radionuclide studies and blood counts. It appeared that an abnormal 111In-scintigraphic activity in the pelvis was related to an abnormal quality and quantity of haematopoietic tissue. To study a correlation with histological subtype grading, the patients were grouped in 4 categories based on clinical-histological results. Thus it could be demonstrated that the presence of 111In-activity in long bones ('scintigraphic extension') is an important parameter in distinguishing patients who are believed to suffer from a primary stem-cell defect, from patients who may suffer from an auto-aggressive disorder.