Peripheral blood (PB) CD34+ cells enumeration is currently the most reliable method to guide the timing of stem cell harvest. However, its usage is restricted by being technically challenging, costly, and time-consuming. Immature reticulocyte fraction (IRF) determination, which is simpler and cheaper and has a faster turn-around time, has been proposed for a similar purpose. The purpose of this study is to evaluate the value of IRF in guiding stem cell harvest and examine the correlation between IRF and PB CD34+ cells count. Daily pre-harvest tests, i.e. PB CD34+ cells and IRF from 21 patients scheduled for autologous PBSC transplant were assessed. Stem cells harvests were commenced when the PB CD34+ cell count were more than 10 cell/ul. A total of 205 pre-harvest tests were analysed. Following stem cell mobilisations, both the IRF and PB CD 34+ cell counts rose with a variable pattern. In this study, we observed that the IRF peaks preceded the PB CD34+ count by 2 days. On the day of stem cell harvest, all the peak IRF values were >0.3. The PB CD34+ cell counts correlated with the harvested stem cell yield, whereby r2 = 0.77, p < 0.021. In autologous stem cell mobilisation, we believe that IRF is a useful screening tool to predict the rise of the PB CD34+ cell counts as it is a simple, fast and less costly. An IRF of > 0.3 may be used as a cut-off value for the initiation of PB CD34+ quantifi cation prior to stem cell harvest.
Peripheral Blood Stem Cell Transplantation ; Hematopoietic Stem Cells

Anaplastic large cell lymphoma (ALCL) is a rare tumour, accounting for approximately 3% of adult non-Hodgkin lymphomas.1 Primary systemic ALCL frequently involves both lymph nodes and extranodal sites. A 44-year-old woman presented with a firm, mobile mass in the left iliac fossa region. Ultrasound findings showed a well defined inhomogenous soft tissue mass, measuring 4x4x2.6cm in the deep subcutaneous region. Histopathological examination revealed that the mass was infiltrated by large lymphoid cells with marked nuclear atypia including kidney-shaped nuclei. These neoplastic cells expressed anaplastic lymphoma kinase (ALK) (both nuclear & cytoplasmic staining), CD30 and EMA but not for T-cell (CD45RO and CD3), and B-cell (CD20 & CD79α) markers. Fluorescence in situ hybridization (FISH) analysis showed a t(2;5)(p23;q35) chromosomal translocation. Subsequently the patient developed shortness of the breath and a thoracic computed tomography (CT) scan showed a mass encasing the right upper lobe bronchus. She also had bilateral axillary lymph nodes, measuring 1 cm in diameter (biopsy was not done). The mediastinum and endobronchial region did not show any abnormalities. She received 6 cycles of CHOP chemotherapy and remained disease free 2 years after diagnosis. ALCL, rarely present as a soft tissue tumour and this disease should be included as a differential diagnosis of any soft tissue mass.