Patchy haemopoiesis in long‐term remission of idiopathic aplastic anaemia

Abstract

13 patients with idiopathic aplastic anaemia in remission for more than 2 years were examined to define the haemopoietic status by means of bone marrow scintigraphy, ferrokinetics and bone marrow culture for haemopoietic progenitor cells. Haemoglobin levels reached the normal range in all these patients although mild neutropenia and thrombocytopenia were still observed in 5 patients. Bone marrow scintigrams using indium‐111 showed normal distribution in 2, diffuse low accumulation in 3, patchy distribution in 7, and expanded distribution with patchy uptake in 1 patient. The defective haemopoiesis was also confirmed by ferrokinetic and bone marrow culture studies. The patchy haemopoiesis appears to characterize the residual marrow damage in remission of idiopathic aplastic anaemia.

Hemopoietic improvement following fetal liver infusion in aplastic anemia

“…0 5 ) among those who lived for more than 12 months as compared to those who died or were lost to follow-up in less than 9 months. Incomplete marrow recovery following FLI and other agents may reflect permanent damage to hematopoietic stem cells or persistent marrow suppression (35). Persistent marrow damage may increase a patient's risk of developing further marrow aplasia, PNH or leukemia.…”

“…Patients and methods 41 patients with aplastic anemia received one or more fetal liver infusions between September, 1976 andNovember, 1987. 35 has severe (20) and 6 moderate aplastic anemia. 5 of the latter patients had received androgens and/or corticosteroids for periods of 1-14 months and had failed to respond.…”

Radionuclide imaging of bone marrow disorders

“…Another study was performed in patients with AA in remission for more than 2 years. Bone marrow scintigrams using 111 In-Cl 3 showed patchy haematopoiesis which appeared to characterize the residual marrow damage in AA remission [30]. …”

Recent advances in understanding clonal haematopoiesis in aplastic anaemia

“…Additionally, more than half of AA patients acquire detectable paroxysmal nocturnal haemoglobinuria (PNH) cell clones lacking surface glycosylphosphatidylinositol (GPI)-linked proteins due to somatic mutations in the PIGA gene(de Planque, et al 1989, Frickhofen, et al 2003, Sugimori, et al 2006, Tichelli, et al 1988). Morphological findings of patchy haematopoiesis, commonly seen in bone marrow biopsies of AA patients, have also been proposed to be a possible histopathological correlate of clonal haematopoietic recovery(Hotta, et al 1990, Huic, et al 2002)…”

“…Additionally, more than half of AA patients acquire detectable paroxysmal nocturnal haemoglobinuria (PNH) cell clones lacking surface glycosylphosphatidylinositol (GPI)-linked proteins due to somatic mutations in the PIGA gene (Tichelli et al, 1988;de Planque et al, 1989;Frickhofen et al, 2003;Sugimori et al, 2006). Morphological findings of patchy haematopoiesis, commonly seen in bone marrow biopsies of AA patients, have also been proposed to be a possible histopathological correlate of clonal haematopoietic recovery (Hotta et al, 1990;Huic et al, 2002). Despite the early recognition of AA as a pre-leukaemic state (Marsh & Geary, 1991;Socie, 1996), it was only recently that our ability to detect clonal changes expanded beyond detection of gross cytogenetic alterations and PNH.…”