Eric R. Rosenbaum

Validation of a formula for predicting daily CD34(+) cell collection by leukapheresis.

BACKGROUND AIMS The ability to predict how many CD34(+) cells a donor will collect on a given day is vital for efficient leukapheresis. METHODS We validated a formula to predict daily CD34(+) cell collections by leukapheresis, calculated as follows: (peripheral blood CD34(+) cells/L) × (adjusted collection efficiency of 30%)/body weight (kg), multiplied by the number of liters processed. This validation was performed from 234 donors undergoing 30 L large volume leukapheresis (LVL) and 162 donors undergoing smaller collections (non-LVL). The LVL group consisted of 811 collection events (625 multiple myeloma, 186 non-myeloma). The non-LVL group consisted of 224 collection events (196 multiple myeloma, 28 non-myeloma). All predicted and observed CD34(+) cell collection numbers were plotted (predicted versus observed) and assessed using linear regression analyses. Linear correlation coefficients (r-values), slopes and intercepts of the regression lines were evaluated. RESULTS Predicted versus observed data points across all quantities of CD34(+) cells/kg collected by both LVL and non-LVL had strong r-values of 0.947 and 0.913, respectively, demonstrating near perfect positive linear correlations. Data for LVL collections subgrouped by number of cells collected (poor, intermediate and good), mobilization regimen, collection day and diagnosis were analyzed the same way and showed consistent findings. CONCLUSIONS We have validated a formula with a strong ability to predict collection of CD34(+) cells/kg that would allow for individualization of collection for any donor once the peripheral blood CD34(+) cell count and optimal goal of collection were known; to date this has not been published by other groups.

First Reported Case of Ehrlichia ewingii Involving Human Bone Marrow

ABSTRACT A 65-year-old female with a history of multiple tick bites presented with fever and pancytopenia. Intracytoplasmic rickettsial morulae were detected on peripheral smear and bone marrow biopsy specimens, and PCR amplified Ehrlichia ewingii DNA from both specimens. To our knowledge, this is the first report of E. ewingii infection of human bone marrow.

Hematopoietic progenitor cell collection after autologous transplant for multiple myeloma: low platelet count predicts for poor collection and sole use of resulting graft enhances risk of myelodysplasia

Collection of hematopoietic progenitor cells (HPC) after previous autologous hematopoietic progenitor cell transplant (aHCT) was studied in 221 patients with multiple myeloma (MM). With a total of 333 collections, the median number of CD34+ cells collected was 4.7 × 106 CD34+ cells/kg, and 74% of the patients collected ⩾2.5 × 106 CD34+ cells/kg. Among 26 variables examined, the strongest predictor for poor collection was a platelet count <100 × 106/l before mobilization (P<0.001). A subsequent aHCT was performed in 154 of the 221 patients. Sole use of HPC procured after aHCT in 86 patients was associated with delayed platelet recovery (P<0.001) and linked to development of myelodysplastic syndrome (MDS)-associated cytogenetic abnormalities (MDS-CA; P=0.027, odds ratio (OR) 10.34) and a tendency towards clinical MDS/acute myeloid leukemia (AML; P=0.091, OR 3.57). However, treatment-related mortality (P=0.766) and time to absolute neutrophil count recovery ⩾0.5 × 109/l (P=0.879) were similar to when a pre-aHCT graft was used. Indeed, adding HPC collected before any aHCT neutralized the risk of MDS-CA or MDS/AML. Therefore, we advise generous initial HPC collection to broaden the salvage armamentarium for patients with MM.

Possible Transfusion-Transmitted Babesia divergens–like/MO-1 Infection in an Arkansas Patient

A patient with asplenia and multiple red blood cell transfusions acquired babesiosis infection with Babesia divergens-like/MO-1 organisms and not Babesia microti, the common United States species. He had no known tick exposure. This is believed to be the first transfusion-transmitted case and the fifth documented case of B. divergens-like/MO-1 infection.

Analysis of CD34+ cell collection using two mobilization regimens for newly diagnosed multiple myeloma patients reveals the separate impact of mobilization and collection variables.

Mobilization regimens for CD34+ cells have generally been judged successful based on the number of cells collected without evaluating mobilization separately from collection. Using retrospective data for patients who collected CD34+ cells on Total Therapy protocols 3a/3b (VTD‐PACE) and Total Therapy 4/5 using a novel regimen that added low dose melphalan to VTD‐PACE (MVTD‐PACE), we analyzed mobilization and collection variables separately. A significant difference favoring MVDT‐PACE was found in mean CD34+ cells/µL on day 2 of collection and in mean ratio of CD34+ cells/µL on day 2 to day 1. However, because apheresis variables and growth factor dose during collection were manipulated to optimize individual collections, the two regimens were not significantly different when the mean total CD34+ cells ×106/kg collected was compared. Thus, when evaluating a chemotherapy regimen or new growth factor for mobilization, it is important to realize that total CD34+ cells collected is dependent on both mobilization and collection variables. J. Clin. Apheresis 29:251–255, 2014.

Bilateral optic neuritis due to malaria.

Malaria is a mosquito-borne infectious disease caused by protists of the genus Plasmodium. Malaria is widespread in tropical regions around the equator, including much of sub-Saharan Africa, Asia, and the Americas, and uncommonly seen in the developed world. Although a variety of ocular manifestations have been linked to malaria, optic neuritis is rare. We report a patient who developed bilateral optic neuritis after he was treated successfully for acute falciparum malaria.

Obstetric anesthesia for harlequin ichthyosis: a unique challenge.

Harlequin ichthyosis (HI) is a rare disorder of defective lipid transport resulting in severe epidermal hyperkeratosis producing large plate-like scales. Although mortality is high, improved treatments have allowed some with HI to survive into their third and fourth decades. However, until this case, there have been no known reports of pregnancy followed by birth of a healthy neonate to a mother with HI. We report one of the only approximately 25 known current HI survivors worldwide unique in having carried a pregnancy to full term and outline challenges for the anesthesiologist during labor and delivery.

Umbilical Cord Blood Collection: A Simple Procedure With a Significant Learning Curve [25O]

INTRODUCTION: Umbilical cord blood contains life-saving stem cells used for hematopoietic transplant. It is usually discarded as medical waste by obstetricians. We hypothesized that the number of units acceptable for public banking would increase as collectors gained experience with the procedure. METHODS: Collection of cord blood units (CBU) for the Cord Blood Bank of Arkansas is limited to term deliveries in interested patients who consent, and collections occur at every delivery site in the state. Public CBU are banked based on total nucleated cell count (TNC) and volume. CBU volume alone is examined here as a surrogate marker of CBU adequacy because it is most likely to be modified by the delivering providers collection technique, and is closely linked to TNC. RESULTS: Between 2011–2014, 101 out of 400 CBU donated (25.3%) met acceptance criteria for banking, which is comparable to the published acceptance rate of other cord blood banks. The number of CBU meeting criteria for banking increased each year: 6 of 48 in 2011 (12.5%), 26 of 96 in 2012 (27.1%), 30 of 126 in 2013 (23.8%), and 39 of 130 (30%) in 2014. The number of collections a provider had performed was associated with a higher volume CBU with each collection (r squared=25%). CONCLUSION: Experience with collecting cord blood improves unit acceptability for storage. Therefore, training in CBU collection during obstetrical training should be associated with improved CBU collection in independent practice, and appears to be an overlooked factor that may improve the overall success of cord blood banking.

Rhizopus Keratitis Associated with Poor Contact Lens Hygiene

We report a case of Rhizopus keratitis in a young woman with poor contact lens hygiene. The mold was highly sensitive to treatment with amphotericin 0.15% drops, after a relatively prompt diagnosis. Obtaining cultures of both corneal infiltrates and presumably infected contact lenses may help to avoid a delay in proper treatment.

Rituximab and intermediate‐purity plasma‐derived factor VIII concentrate (Koate®) as adjuncts to therapeutic plasma exchange for thrombotic thrombocytopenic purpura in patients with an ADAMTS13 inhibitor

Thrombotic thrombocytopenic purpura (TTP) results from a congenital or acquired deficiency of the von Willebrand factor (vWF)‐cleaving protease ADAMTS13. The disease can be fatal and hence treatment should be initiated promptly. Therapeutic plasma exchange (TPE) remains the standard treatment along with adjunct therapies including steroids and immunosuppressive drugs. Addition of rituximab to TPE has been shown to be beneficial in refractory/relapsing TTP; however, TPE results in removal of rituximab from the circulation requiring more frequent dosing of rituximab to achieve a favorable outcome. The intermediate‐purity plasma‐derived Factor VIII concentrate (FVIII) Koate® contains the highest amount of ADAMTS13 activity yet reported and has been used successfully in treating congenital TTP. Here we report our experience with addition of this FVIII concentrate to rituximab, corticosteroids and TPE in three TTP patients with an ADAMTS13 inhibitor to permit withholding TPE for 48 h after rituximab infusion. J. Clin. Apheresis 30:50–54, 2015.