Prevalence of Red Blood Cell Alloimmunization Among Pediatric Patients With Sickle Cell Disease in Saudi Arabia.

OBJECTIVE: Sickle cell disease (SCD) is a common hereditary hemoglobin disorder worldwide. One of the main treatments for patients with SCD is the requirement for blood transfusions. Posttransfusion alloimmunization with red blood cell (RBC) antigens continues to be a major risk factor for SCD. The objective of this study was to determine the rate, nature, and risk factors of red cell alloimmunization among pediatric patients with SCD in our center and compare our results with published reports from Saudia Arabia SA, regional countries, and some international countries. MATERIALS AND METHODS: A retrospective chart review of patients with SCD at King Abdulaziz Medical City-Jeddah, between 2008 and 2019 was performed. Demographic characteristics and transfusion histories were recorded. Blood samples were analyzed for alloimmunization using immunohematologic techniques. RESULTS: In total, 121 patients were analyzed. Alloantibodies were detected in 21 patients (17.4%) and were mostly single in 15 patients (71.4%), anti-K (23.7%), anti-E (19.0%), and anti-S (9.5%). The other 6 patients (28.6%) had multiple alloantibodies, especially the combination of anti-C and anti-K (9.5%) and the combination of anti-C and anti-E (9.5%). Alloantibody levels were significantly higher in patients with frequent hospital admissions (>5 times annually), those who had an exchange blood transfusion, those younger than 3 years old, and those who received a larger number of blood units ( P ≤0.05). CONCLUSION: The rate of RBC alloimmunization is determined and considered relatively low compared with that in other nations. Matching for extended RBC antigens to include ABO, RH (D, C, c, E, e), K, Fy a , Fy b , Jk a , and Jk b antigens in the screening panel for donors and recipients is highly recommended to ensure better transfusion practices and avoid transfusion-related complications.

Establishment of reference interval for hemoglobin A1C and other hemoglobin subfractions for healthy Saudi adults.

BACKGROUND: The establishment of Reference Intervals (RIs) for Hemoglobin A1C and other hemoglobin subfractions (A1A, A1B, F, LA1C, A0) is of utmost importance in screening, diagnosing, and monitoring diabetes and other hemoglobin abnormalities through the application of high-pressure liquid chromatography (HPLC) technique. Because there are no locally established RIs for these parameters, it is essential to establish RIs specific to the Saudi population to accurately diagnose and monitor diabetic individuals and identify abnormal levels in hemoglobin subfractions. METHODS: As part of the IFCC global multicenter study of laboratory reference values, a cross-sectional study was conducted in Saudi Arabia. The study involved recruiting a total of 381 healthy adult subjects (>18 years, BMI 28.3 ± 6 kg/m2). Blood samples were analyzed for A1C, biochemical and other immunoassay parameters. The need for RIs based on sex, age, and BMI was determined using the standard deviation ratio (SDR) through a 3-level nested ANOVA. RESULTS: Based on the threshold of SDR≥0.4, RIs for A1C and other Hb subfractions were not partitioned by sex or BMI, but partitioned by age (<45 & ≥45 years) for A1C, LA1C, A0 and F. Spearman's correlation between glucose, insulin, and C-peptide showed a positive association with different hemoglobin subtractions of A1B, F, A1C, and LA1C. The RIs were obtained by using the parametric method and the latent abnormal values exclusion (LAVE) principle was applied on A1C. CONCLUSION: This study established RIs for A1C and other Hb subfractions for healthy adult Saudis. Age was found to be an important source of variation for most of the parameters including A1C. These findings will enhance the understanding and clinical decision-making concerning A1C and other hemoglobin subfractions. The elevated upper limit of RIs for A1C reflects the high prevalence of diabetes in the Saudi population specially in those with increased age.

Paroxysmal nocturnal hemoglobinuria in a patient post COVID-19 virus infection: A case report with literature review.

COVID 19 is a serious infection that originated in Wuhan, China and has resulted in worldwide morbidity and mortality. It continues to be a major health concern in 2022, being associated with multiorgan failure. Although the pathophysiology of the disease and its complications are not well understood, it is believed that a cytokine storm, triggered by complement activation may be responsible for the severity and complications of the disease. As of now, there is no definitive treatment available. Hematological changes associated with COVID-19 include lymphopenia, anemia, thrombocytopenia, disseminated intravascular coagulopathy, and thrombosis. Paroxysmal nocturnal hemoglobinuria (PNH), on the other hand, is an acquired clonal hematopoietic stem cell disorder that occurs due to an acquired PIG-A mutation affecting the hematopoietic stem cells. Interestingly, PNH exhibits some clinical and laboratory manifestations like those seen in COVID-19. In this report, we present a rare case of PNH that developed following a COVID-19 infection.

Risk Factors for Postoperative Infections in Cardiac Surgery Patients: A Retrospective Study.

Background and objective Cardiac surgery is one of the most common surgical procedures globally; its incidence has been on the rise due to the faster pace of population aging thanks to technological and epidemiological advances. Patients who undergo cardiac surgeries may face various postoperative complications that might affect their survival, and one of these major complications is infection. Nosocomial pneumonia, surgical site infection (SSI), mediastinitis, bacteremia, and sepsis are common infections encountered after surgeries. In this study, we aimed to determine the common risk factors related to postoperative infections at the King Faisal Cardiac Center from January 2014 to September 2020. Materials and methods  Records from 364 patients who underwent cardiac surgery and were aged above 18 years were assessed for postoperative infections in this retrospective cohort study. Patients who were immunosuppressed or had active systemic infections were excluded. Consent was waived by the Institutional Review Board. All procedures were performed at the King Faisal Cardiac Center, National Guard Hospital, Jeddah. Results Of the total 364 patients, 105 were women and 259 were men. The mean age of the cohort was 59 years (SD = 13) and the mean BMI was 29.1 kg/m2 (SD = 5.3). The study population showed a high prevalence of cardiac risk factors and diseases: diabetes (n = 244, 67%), hypertension (n = 230, 63%), dyslipidemia (n = 144, 40%), smoking (n = 80, 22%), heart failure (n = 41, 11%), and chronic obstructive pulmonary disease (n = 6, 1.6%). The overall rate of postoperative infection was 32.7% (n = 120), and 17 (14%) of these infected patients underwent reoperations for infection. Conclusion Based on a thorough analysis of 364 patients undergoing various cardiac surgical procedures, including a multivariate analysis accounting for preoperative factors, there was a significant association between postoperative infections and hypertension, diabetes, increased preoperative activated partial thromboplastin time, and elevated HbA1c.

Establishment of reference intervals for hematological parameters of adult population in the western region of Saudi Arabia.

BACKGROUND: Most of hematology laboratories in Saudi Arabia utilize the reference intervals (RIs) provided by instrument manufacturers. This study aimed to define RIs of hematological parameters for adult population in the western region of Saudi Arabia and to explore their specific features from an international perspective. METHOD: This study was conducted according to the harmonized protocol of IFCC Committee on RIs and Decision Limits. Blood samples collected from 409 healthy Saudi males and females adults were analyzed for complete blood count (CBC) by using Cell-Dyn Sapphire analyzer and for iron profile by using Architect analyzers. The needs for RIs partitioned by sex and age was based on standard deviation ratio (SDR) and/or bias ratio (BR). RIs were derived parametrically with/without application of the latent abnormal values exclusion method (LAVE). RESULTS: Based on thresholds of SDR≥0.4 and/or BR≥0.57, RIs were partitioned by sex for red-blood cell count, hemoglobin, hematocrit, red cell distribution width, erythrocyte sedimentation rate, iron, transferrin, ferritin, eosinophil, platelet, plateletcrit, etc. Partitioning by age was not necessary for any of the analytes. LAVE procedure caused appreciable changes in RI limits for most erythrocyte and iron parameters but not for leukocyte parameters. Comparable to other non-IFCC studies on CBC RIs, the RBC and hematocrit (Ht) ranges have shifted to a higher side in both genders. After applying the LAVE method, the male and female RIs for Hb were 4.56 to 6.22 ×106/µL and 3.94 to 5.25 ×106/µL respectively while RIs for Ht were 40.2 to 52.0% and 33.6 to 44.5% respectively. CONCLUSION: LAVE method contributed to reducing the influence of latent anemia in deriving RIs for erythrocyte related parameters. Using the up-to-date methods, the RIs of CBC determined specifically for Saudis will help to improve the interpretation of test results in medical decision making.

The association between preoperative anemia, blood transfusion need, and postoperative complications in adult cardiac surgery, a single center contemporary experience.

BACKGROUND: The impact of preoperative anemia on postcardiac surgery outcomes is an area of great debate. Although several large-scale studies have been conducted, they have demonstrated conflicting results. A limited number of studies have been conducted in the Middle East. The primary aim of this study was to investigate the association between preoperative anemia and the need for blood transfusions, as well as major postoperative complications. METHODS: Adult patients who underwent cardiac surgery at King Faisal Cardiac Center in Jeddah between June 2016 and January 2020 were included in this retrospective cohort study. The study excluded patients with hereditary preoperative anemia. Among the variables studied were variables related to demographics, comorbidities, laboratory data, operation-related data, in-hospital complications, and mortality. RESULTS: The mean preoperative hemoglobin (Hb) level was 13.2 g/dL (SD ± 1.8). The overall mortality rate was 4.6%. A lower preoperative Hb level (p value = 0.016), postoperative day 1 WBC count (p-value = 0.003), and prolonged cross clamp time (p value < 0.001) were significantly associated with mortality. A lower Hb level during the preoperative period or within the first three days of surgery was associated with a higher blood transfusion requirement. However, there was no significant association between blood transfusion and postoperative complications. A multivariate stepwise logistic regression model was developed and several pre and intra operative factors were predictive of the need PRBCs transfusion after cardiac surgery (which included: older age, female gender, lower pre-operative hemoglobin and longer cardio-pulmonary bypass time), with had a predictive accuracy of around ~ 86%. CONCLUSION: Based on our single center study, patients with preoperative lower Hb levels are at higher risk of mortality. However, blood transfusion does not seem to increase the risk of postoperative complications. Optimal utilization of blood products is an important quality metric and identification of patients at higher risk of requiring PRBCs transfusion prior to cardiac surgery can help in implementing pre or intra operative strategies to minimize the need for transfusion.

Autologous peripheral blood stem cell mobilization and collection in patients with lymphoma and multiple myeloma: A single-center experience using the plerixa for pre-emptive approach.

OBJECTIVES: To review and assess the efficiency of pre-emptive plerixafor administration for poor mobilization (PM) and to review and assess mobilization efficiency (≥2×106 CD34+ cells/kg) in patients who received autologous stem cell transplantation for lymphoma and multiple myeloma (MM) at the Department of Adult Hematology/Blood Marrow Transplant, Princess Noorah Oncology Center, King Abdulaziz Medical City, Jeddah, Saudi Arabia, over the past 7 years. METHODS: This retrospective study evaluated all patients with MM and lymphoma undergoing peripheral blood stem cell mobilization and collection at our institution between February 2014 and August 2021. Plerixafor was administered pre-emptively by a plateau of <10 peripheral blood CD34+/µl after chemotherapy-based mobilization or CD34+ of <8/µL on day 4 after mobilization with G-CSF alone. Between peak CD34+ levels of 10-15/µl, plerixafor will be used at the discretion of the treating physician. RESULTS: In total, 215 patients were enrolled. Among them, 80% had peak CD34+ level ≥20/µL, 11% had clear poor mobilization (peak CD34+ levels <10/µL), and 9% had borderline PM (CD34+ between 10-19/µL). Plerixafor was administered pre-emptively in 13% of the patients and 75% of patients with borderline PM were collected without plerixafor, suggesting that plerixafor is not needed if CD34+ >15/µL on the anticipated collection day. Mobilization failed in only one patient (<1%). CONCLUSION: Our data showed that with plerixafor pre-emptive administration, the primary endpoint was achieved for most patients identified with PM, preventing the need for a second mobilization attempt.

Prognostic relevance of combined IDH1 and NPM1 mutations in the intermediate cytogenetic de novo acute myeloid leukemia.

Despite the great advance in treatment, cytogenetically normal Acute myeloid leukemia (CN-AML) is still a challenging entity. The discovery of IDH1 mutation in AML together with the frequent co-mutations; NPM1 and FLT3-ITD throughs a new insight into the pathogenesis and outcome of CN-AML. Recently, there has been an increasing number of recurring mutations in other genes for which the forecasting effect is still required. Despite the large number of risk variables established, there are relatively few prognostic indicators that can help in treatment decisions in AML patients. This study aimed at recording the frequency of IDH1 and NPM1 mutations in newly diagnosed AML and, dual clinicopathological significance. IDH1 and NPM1 mutations were analyzed using High-Resolution Melting curve analysis PCR in 78 newly diagnosed AML patients; 30 pediatric and 48 adult AML patients. IDH1 mutation was detected in 6 out of the 48 adult AML cases (12.5%) and all of them had intermediate cytogenetic prognostic stratification. 5/6 mutant IDH1 patients showed NPM1 co-mutation (P-value= 0.008). Mutant IDH1 patients showed significant resistance to induction therapy (P-value <0.001) and even those who achieved complete remission were relapsed later. Within the intermediate cytogenetic group, the IDH1 mutated patients had short overall survival (HR 12.9, 95% CI (3.1- 53.45) and event-free survival (HR 15.7, 95% CI (2.99-82.72) and P-value <0.001). IDH1 mutation is closely linked to the intermediate cytogenetic stratified group and in particular old age patients and has a great impact on their survival.

Diagnostic accuracy of reticulocyte parameters on the sysmex XN 1000 for discriminating iron deficiency anaemia and thalassaemia in Saudi Arabia.

INTRODUCTION: Iron deficient erythropoiesis and Thalassaemia are both associated with microcytic erythropoiesis albeit from different pathological mechanisms. Given the high prevalence of Hemoglobinopathies in the Mediterranean region, discriminating these two conditions is important. Several algorithms using conventional red cell indices have been developed to facilitate diagnosis, however, their diagnostic accuracy is low. The new generation haematology analyzers enabled the use of more innovative parameters such as reticulocyte parameters. We aimed to evaluate the diagnostic performance of the reticulocyte parameters on the Sysmex XN 1000 to distinguish between IDA and Thalassemia in our population. METHODS: We performed a retrospective analysis of blood samples sent to our laboratory for haemoglobin electrophoresis screening. We categorized our cohort into Thalassemia and Iron Deficient patients based on known diagnostic criteria. We analyzed the reticulocyte parameters using receiver operator curve analysis (ROC) and determined the cut off value for each parameter. RESULTS: Reticulocyte parameters most accurate for discriminating IDA from Thalassemia patients was: RET, RET-HE and IRF. The RET-HE had the best statistical significance for IDA patients with AUC = 0.69 for cut off 22.25. The RET-HE for dual positive patients was more accurate with AUC = 0.78 for cut off 21.25. The IRF had the best statistical significance for Alpha Thalassemia with AUC = 0.66 for cut off value 18. CONCLUSION: An IRF cut off below 15.5 and RET-HE cut off below 22.25 was the most accurate variable in predicting IDA with a sensitivity of 59.4% and 68.3%.

Outcomes of a preoperative risk-based transfusion assignment protocol in sickle cell disease patients: a single-center retrospective study from Saudi Arabia.

Many patients with sickle cell disease (SCD) need surgical management during their lifetime. The best approach for preoperative transfusion in SCD is still to be determined. In this single-center retrospective study, we included HBSS/HBS-Beta0-thalassemia patients younger than 16 years of age who underwent surgery between January 2008 and July 2019. Preoperative transfusion assignment (PTA) was based on SCD severity and surgical risk. Patients were assigned to no transfusion, simple transfusion, or exchange transfusion. A total of 284 patients were identified and 66 (23%) underwent 78 procedures. Mean age at the time of procedure was 8 (5-11) years, mean baseline hemoglobin was 8.5 (7.8-9.3) g/dl, and mean hemoglobin F was 18.4 ± 8.2%. SCD severity was low-risk in 57 (73%) and high-risk in 21 (27%) patients. Surgical risk was low-risk in 20 (25.6%) and medium-risk in 58 (74.4%) procedures. PTA was no transfusion in 17 (22%), simple transfusion in 40 (51%), and exchange transfusion in 21 (27%) procedures. Postoperative complications occurred in five (6.4%) of procedures only in the simple transfusion group (three acute chest syndrome, one hemolytic anemia, one pain crisis) undergoing medium-risk surgery. Preoperative risk-based transfusion assignment is feasible. Despite a high baseline hemoglobin level in the no transfusion group, none of the patients developed postoperative complications. It is possible that the high baseline hemoglobin F phenotype was protective and indicates the need to study the risk/benefit of interventions used in this phenotype.

Establishment of reference intervals for immunoassay analytes of adult population in Saudi Arabia.

Background This is a second part of report on the IFCC global multicenter study conducted in Saudi Arabia to derive reference intervals (RIs) for 20 immunoassay analytes including five tumor makers, five reproductive, seven other hormones and three vitamins. Methods A total of 826 apparently healthy individuals aged ≥18 years were recruited in three clinical laboratories located in western, central and eastern Saudi Arabia using the protocol specified for the global study. All serum specimens were measured using Abbott, Architect analyzers. Multiple regression analysis (MRA) was performed to explore sources of variation of each analyte: age, body mass index (BMI), physical exercise and smoking. The magnitude of variation of reference values (RVs) attributable to sex, age and region was calculated by ANOVA as a standard deviation ratio (SDR). RIs were derived by the parametric (P) method. Results MRA revealed that region, smoking and exercise were not relevant sources of variation for any analyte. Based on SDR and actual between-sex differences in upper limits (ULs), we chose to partition RIs by sex for all analytes except for α-fetoprotein and parathyroid hormone (PTH). Age-specific RIs were required in females for ferritin, estradiol, progesterone, testosterone, follitropin, luteotropin and prolactin (PRL). With prominent BMI-related increase, RIs for insulin and C-peptide were derived after excluding individuals with BMI > 32 kg/m2. Individuals taking vitamin D supplements were excluded in deriving RIs for vitamin D and PTH. Conclusions RIs of major immunoassay analytes specific for Saudi Arabians were established in careful consideration of various biological sources of variation.

Changes in Hematological Indices and Lymphocyte Subsets in Response to Platelet Apheresis Donation.

BACKGROUND: Platelet apheresis is a technique in which whole blood is collected from a donor followed by platelet (PLT) separation. Platelet apheresis has a significant impact on some biochemical indices after donation. This study aimed to investigate the impact of platelet apheresis on complete blood count (CBC) and lymphocyte subsets over a typical interdonation interval. METHODS: Healthy male subjects (n = 10) were recruited to study changes in CBC and lymphocyte subsets before and at three intervals following platelet apheresis. Repeated measures ANOVA was used to compare quantitative variables between different visits. RESULTS: Following platelet apheresis, platelet count decreased 30% at 24 hours after donation (p < 0.001) compared to the baseline count with significant repeated ANOVA across different visits (p < 0.001, Eta = 0.558). No changes were observed in other variables of CBC. The lymphocyte subsets including CD4, CD8, and CD4/CD8 ratio were decreased at 24 hours after donation (-0.6%, -0.4% and -0.7%, respectively) but none was significant. At 24 hours, the proportion of CD19 and CD16-56 were slightly increased (1.6%, 3.3%, p > 0.05, respectively). CONCLUSIONS: The significant reduction in PLT count after 24 hours of plateletpheresis may have adverse health effects on PLT donors. Platelet apheresis has no significant effect on lymphocyte subsets of the donor.

The Safety of the Kahook Dual Blade in the Surgical Treatment of Glaucoma.

Intraocular pressure defects remain a significant problem in the medical field. Several methods have been employed to help reduce the effect of intraocular pressure (IOP), all of which have their merits and demerits. Considered in this paper are surgery and the Kahook Dual Blade (KDB; Kahook, New World Medical, Inc., Rancho Cucamonga, CA) process invented and tested during previous studies to reduce IOP. This study examines both methods; first, in combination with cataract surgery, and then, separately, to assess their effectiveness in reducing IOP. Objective The focus of the research is to establish the effectiveness and safety associated with goniotomy while utilizing the Kahook Dual Blade (KDB) procedure for reducing IOP and bringing down the reliance on hypotensive agents in a variety of glaucoma types, either independently or when combined with phacoemulsification (phaco) within the follow-up duration (four to seven months). Methods and design The setting was the outpatient clinics in Al-Maghrabi Hospital in Medina. It involved the use of a retrospective study for the study design. Fifty eyes from a total of 45 patients were reviewed. There was KDB in 10 eyes while KDB was integrated with the cataract surgical procedure in 40 eyes. The de-identified clinical data have been collected by data collectors, who took into account IOP measurements both postoperatively and preoperatively, types of treatment used, side effects, and whether or not there was additional surgery required during the four to seven months observation period. Results Seventy percent of the cases in this research had primary open-angle glaucoma. Additional diagnoses were close-angle, normal-tension, pseudoexfoliative glaucoma, and pigmentary. There was a decline in the value of the mean baseline IOP from the earlier 20.66 mmHg ± 7.89 (SD) to a staggering 14.66 ± 3.9 mmHg within the postoperative period (four to seven months) for all 50 eyes, and there was a reduction in hypotensive medication use from 1.54 ± 1.26 to 0.22 ± 0.51 (SD) (P<0.05 and P = .005) for all 50 eyes. In the KDB + phaco group, the mean baseline IOP decreased from 20.75 ± 8.1 (SD) to 13.8 ± 3.7 (P < 0.05 and P = .000), respectively, and the medications used decreased from 1.32 ± 1.18 (SD) to 0.22 ± 0.48 (SD), whereas in KDB goniotomy alone, the mean baseline IOP decreased from 20.30 ± 7.3 (SD) to 18.0 ± 3.0 (SD) (P< 0.05 and P = 0.00) and there was a reduction in the amount of medications from 2.4 ± 1.26 (SD) to 0.2 ± 0.63 (P< 0.05 and P = 0.000). Eye irritation occurred the most in the KDB + Phaco group, representing 8%, which is resolved within 24 hours postoperatively. As for the KDB only group, hazy vision occurred the most, representing 22% but subsided between two to five days for all patients. Conclusion Affirming the results of the study, the safety and effectiveness of goniotomy with the KDB procedure is certain towards the reduction of IOP and medication usage, either independently or when combined with phacoemulsification during four to seven months of follow-up.

Factors associated with exclusive breastfeeding in relation to knowledge, attitude and practice of breastfeeding mothers in Rabigh community, Western Saudi Arabia.

BACKGROUND: There is much concern about declining rates of exclusive breastfeeding (EBF) all over the world including Saudi Arabia which deprives infants from many immunological, nutritional, and psychosocial benefits. This study was performed to determine EBF prevalence and factors influencing EBF in relation to knowledge, attitude and practice (KAP) of breastfeeding mothers (BFM) in Rabigh, Western Saudi Arabia. METHODS: Data about factors that could be associated with EBF and KAP of BFM were collected by cross-sectional questionnaire-based study from 420 BFM. RESULTS: Prevalence of EBF for 6 months was 27.6% which is far below World Health Organization recommendations. Demographic, socioeconomic, biomedical as well as most studied variables of KAP of 50% to over 90% of participating mothers were adequate to account for low EBF rate. Proper knowledge about benefits of colostrum and continuation of breastfeeding for 2 years was given by only 86.2% and 36.7% of BFM, respectively. The most significant independent factors associated with EBF were perception of sufficient human milk [adjusted odds ratio (AOR) 2.89; 95% confidence interval (CI) 1.72-4.89], absence of nipple pain (AOR 2.77; 95% CI 1.72-4.45) and mothers without university education (AOR 1.86; 95% CI 1.15-3.01). Early introduction of formula in hospital after birth was the main inappropriate feeding practice in 76.2% of infants of BFM. CONCLUSION: Findings of this study should be utilized by Rabigh community and other national or worldwide communities with similar characters to promote EBF by targeted educational programs after identification of significant factors influencing EBF and gaps in KAP of BFM.

Changes in hematological indices and lymphocyte subsets in response to whole blood donation in healthy male donors.

Whole blood donation has immunomodulatory effects, and most of these have been observed at short intervals following blood donation. This study aimed to investigate the impact of whole blood donation on lymphocyte subsets over a typical inter-donation interval. Healthy male subjects were recruited to study changes in complete blood count (CBC) (n = 42) and lymphocyte subsets (n = 16) before and at four intervals up to 106 days following blood donation. Repeated measures ANOVA were used to compare quantitative variables between different visits. Following blood donation, changes in CBC and erythropoietin were as expected. The neutrophil count increased by 11.3% at 8 days (p < .001). Novel changes were observed in lymphocyte subsets as the CD4/CD8 ratio increased by 9.2% (p < .05) at 8 days and 13.7% (p < .05) at 22 days. CD16-56 cells decreased by 16.2% (p < .05) at 8 days. All the subsets had returned to baseline by 106 days. Regression analysis showed that the changes in CD16-56 cells and CD4/CD8 ratio were not significant (Wilk's lambda = 0.15 and 0.94, respectively) when adjusted for BMI. In conclusion, following whole blood donation, there are transient changes in lymphocyte subsets. The effect of BMI on lymphocyte subsets and the effect of this immunomodulation on the immune response merit further investigation.