We report here four cases of genital ulcers that developed after the administration of all-trans retinoic acid (ATRA) for the treatment of acute promyelocytic leukemia (APL). Between October 2007 and March 2010, three males and one female (age range 19-35 years) were identified to have genital ulcers after being prescribed all-trans retinoic acid (ATRA) as a part of chemotherapy for APL. This is the first series of cases describing genital ulcers, as a unique and rare complication of ATRA used for treatment of APL in these patients, with no other cause identified. Following temporary cessation of ATRA for a few days in these three cases, improvement of the ulcers was noted

Compared to the world literature, the most common cause of premature ovarian failure in this study was chemotherapy induced, especially in young girls undergoing bone marrow transplantation. This is due to high prevalence of transplantable hereditary haematological disorders like thalassemia and sickle-cell disease in this part of the world. Current standard of care recommends cryopreservation of ovarian tissue to preserve ovarian function in young girls undergoing bone marrow transplantation for such disorders.

Due to their immunoregulatory properties, several specialized cell subsets, including regulatory T (Treg), invariant natural killer T (iNKT) and regulatory B (Breg) cells, are involved in the pathogenesis of non-Hodgkin lymphoma (NHL). However, the interaction between various cells remains to be elucidated. The aim of the present study was to evaluate the levels of Treg, iNKT and Breg cell subsets and their interrelationships in the peripheral blood (PB) and bone marrow (BM) of patients with B-cell NHL who received rituximab-based regimens and achieved a complete remission. A total of 20 patients and 20 healthy age-and sex-matched controls were prospectively enrolled for investigation of Treg, iNKT and Breg cell subsets in PB and BM by flow cytometry and cell culture. Prior to administration of combination chemotherapy with rituximab, the patients had lower levels of Breg cells and, to a lesser degree, Treg cells, but not iNKT cells, in PB compared with controls. Compartmental differences in the levels of Treg and Breg cell subsets, but not iNKT cells, were observed between PB and BM, suggesting an increase in trafficking through the blood of these regulatory cell subsets to the marrow. Following complete remission, the levels of circulating Treg, iNKT and Breg cell subsets increased. The levels of Treg cells were not significantly associated with iNKT and Breg cell subsets, although negative correlations were observed. Taken together, these results may provide new insights into the potential role of regulatory cell subsets in patients with B-cell NHL. However, whether the observed differences between PB and BM may affect clinical outcomes requires further investigation.

4770 Introduction: The care of patients with Sickle Cell Disease (SCD) is frequently complicated by difficult venous access complicating blood sampling for laboratory investigations including hemoglobin (Hb) measurement. Non-invasive hemoglobin concentration monitoring is a potential solution, albeit not validated yet in patients with SCD. The primary objective of this study was to validate non-invasive pulse CO-oximetry based hemoglobin estimation in this patient population. Methods: We conducted a prospective observational study on patients with SCD admitted to the inpatient wards over 4 weeks in a tertiary care hospital. We estimated a spot Hemoglobin (Sp Hb) measurement using Masimo Pronto-7 Pulse CO-oximetry device (two measurements per patient) and compared it to a venous sample Hb (Reference Hemoglobin; Ref Hb) measured using Abbott CELL-DYN Sapphire hematology analyzer. We calculated Pearson correlation coefficient and coefficient of determination (R2). The multivariable linear regression model of predicting the estimation differences included age, gender, weight, height, blood pressure and reference hemoglobin. Results: We enrolled 98 patients (45 males, 53 females) with a mean age of 26 years (SD 8.8; 14–75) and a mean Ref Hb of 9.2 g/dL (SD 1.5; 5.3–13). The mean Sp Hb was 10.1 g/dL (SD 2.0; 5.3–14.5). The correlation coefficient between the Sp Hb and Ref Hb was 0.54 (R2 = 29%) with a mean difference of 0.9 g/dL (SD 1.7; −4.8 to 4.5). In the multivariable model, gender (p =0.042) and Ref Hb level (p=0.001) were statistically significant predictors for the difference in measurement. A strong correlation between the two CO-oximetry Hb measurements was obtained (correlation coefficient = 0.81, R2 = 65%). Conclusions: Our study demonstrated the validity of the CO-oximetry Hb measurement in adult patients with SCD. Larger prospective studies are needed to confirm our results. Disclosures: No relevant conflicts of interest to declare.

2280 Introduction: Pre-donation screening of blood donors are currently based on venous or capillary blood sampling. Adoption of a non-invasive hemoglobin estimation may increase blood donor recruitment. Masimo Pronto-7 Pulse CO-oximetry device is a spectrophotometry based device used to estimate the hemoglobin (Hb) level non-invasively, waiving the need of blood sampling. It has not been validated in normal blood donors. The primary objective of our study was to validate the pulse CO-oximetry based hemoglobin estimation in normal blood donors. Methods: We conducted a prospective observational study on 106 whole blood donors attending the blood bank of a tertiary care center over 4 weeks. We estimated a Spot Hemoglobin (Sp Hb) concentration using Masimo Pronto-7 Pulse CO-oximetry device (two measurements per donor) and compared it to a venous sample Hb (Reference Hemoglobin; Ref Hb) measured using Abbott CELL-DYN Sapphire hematology analyzer. We calculated Pearson correlation coefficient and coefficient of determination (R2). The multivariable linear regression model of predicting the estimation differences included age, gender, weight, height, blood pressure and reference hemoglobin. Results: We enrolled 106 donors (98 males, 8 females) with a mean age of 27 years (SD 6.2; 18–49) and a mean Ref Hb of 14.2 g/dL (SD 1.2; 11.5–17). The mean Sp Hb was 14.4 g/dL (SD 1.2; 11.3–16.7). The correlation coefficient between the Sp Hb and Ref Hb was 0.46 (R2 = 21%) with a mean difference of 0.2 g/dL (SD 1.2; −4.5 to 3). In the multivariable model, height (p =0.015) and Ref Hb level (p <0.001) were statistically significant predictors of the difference in measurement. There was a strong correlation between the two CO-oximetry Hb measurements (correlation coefficient 0.78, R2 = 60%). Conclusions: Our study demonstrated the validity of the CO-oximetry Hb measurement in normal blood donors and with good reproducibility. Larger prospective studies are needed to confirm our findings. Disclosures: No relevant conflicts of interest to declare.