The effect of caffeine intake and passive smoking on umbilical cord blood unit's quality parameters.

Today cord blood (CB) is a valuable source of hematopoietic stem cells to treat many hematological disorders. One of the limitations of CB utilization is the reduced number of nucleated cells including stem cells. Therefore, CB banks around the world have developed strategies in an attempt to improve donor selection and the quality of the CB inventory. This study aimed to determine the impact of passive smoking and caffeine consumption on CB quality. CBs were obtained from mothers who gave birth at King Abdulaziz Medical City. All mothers gave their informed consent. Personal interviews about the mother's demographics, smoking status and exposure, and caffeine consumption executed, followed by a chart review to analyze maternal and neonatal factors. Laboratory testing was performed on all collected CB units. Using descriptive statistics, maternal and newborn factors were analyzed. T-test or Mann-Whitney U Test, as appropriate, for continuous variables analysis to study the effect of second hand smoking and coffee consumption for the primary outcome. Our study demonstrated a reduction in CB MNC, including lymphocytes, in caffeine consumers among pregnant donors, as well as a reduction in cell potency activities, including total CFU and BFU-E. The effect of passive cigarette smoking on the same cohort was insignificant. Outcome of this study will help in optimizing the quality and quantity of stem cell harvesting from CB to get the maximum benefit and such knowledge will raise the awareness among pregnant women.

Perceptions and Attitudes Regarding Hematopoietic Stem Cell Donation Among Blood Donors in Riyadh, Saudi Arabia.

Introduction In recent years, there has been a growing trend toward using stem cell transplantation for therapeutic purposes, making a positive impact in the medical field. Access to a compatible and willing donor is essential for those therapeutic purposes, yet the current number of registered donors remains inadequate. The present study aimed to investigate the attitude and perception of stem cell donation among blood donors in Saudi Arabia while also exploring their knowledge of hematopoietic stem cells, willingness towards donation, and fear of complications after stem cell donation. Methods A cross-sectional study was implemented to investigate the perception and attitude toward stem cell donation among blood donors in Riyadh, Saudi Arabia, through a validated self-administered questionnaire. The questionnaire comprised 35 questions divided into five sections, namely, demographics, knowledge, attitude, willingness, and fear of stem cell donation. Results The survey was distributed to 400 subjects. Out of the 400 respondents, 98.8% (n=395) were male, and 90.8% (n=363) were Saudi nationals. The majority had a high school level of education (n=259, 64.75%). Only 10.8% (n=43) of the participants were knowledgeable about stem cells. Knowledge of stem cells was highest among females aged 40-49 years, participants knowledgeable of platelet donation, and participants who donated blood more than 10 times (p-value <0.05). Participants with a bachelor's or master's degree had significantly more fear of stem cell donation complications, with a p-value of 0.003. The attitude toward stem cell donation was highly positive. Most participants strongly agreed to donate stem cells to a family member or anyone in need, 94.5% (n=378) and 62% (n=248), respectively. Conclusion Knowledge about stem cell donation among blood donors was scarce, while their willingness to donate after conversing was high. We highly recommend the initiation and establishment of educational programs to increase the knowledge of the public and, specifically, blood donors.

Mesenchymal stem cell therapy: A review of clinical trials for multiple sclerosis.

Multiple sclerosis (MS) is a disease of the central nervous system (CNS) that is the result of the body's own immune cells being auto-reactive to the myelin regions of the body as if these regions were foreign antigens. This demyelination process is damaging to the electrical conductivity of neurons. The current medicines are only capable of fighting off the symptoms of the disease, but not the disease itself. Specialized stem cells, known as mesenchymal stem cells (MSCs), seem to be the candidate therapy to get rid of MS. MSCs can be isolated from multiple sources of the person's body, and even from the umbilical cord (UC) and placenta of a donor. These cells have anti-inflammatory effects so they can target the overactivity and self-antigen attacks by T cells and macrophages; this immune system overactivity is characteristic of MS. MSCs show the ability to locate into brain lesions when injected and thus can compensate for the loss of the brain function by differentiating into neuronal precursor cells and glial cells. The author has listed tables of clinical trials that have utilized MSCs from different sources, along with the years and the phase of study completed for each trial. The consensus is that these cells work on inhibiting CD4+ and CD8+ T cell activation, T regulatory cells (Tregs), and macrophage switch into the auto-immune phenotype. The best source of MSCs seems to be the UC due to the easiness of extraction, the noninvasive method of collection, their higher expansion ability and more powerful immune-modulating properties compared to other locations in the body. Studies showed there was a significant decline of mRNA expression of several cytokines after the administration of MSCs derived from the UC (UCMSCs). Other researchers were able to repair the defects of Tregs in MS patients by co-culturing Tregs from these patients with UCMSCs, which decreased the production of the pro-inflammatory cytokine IFN γ , and also suggested a strong link between Tregs lack of functionality in MS patients with the pathogenesis of the disease.

Chances of Finding Matched Unrelated Donors for Saudi Patients in Need of Hematopoietic Stem Cell Transplantation.

Finding HLA-matched donors for patients in need of hematopoietic stem cell transplantation (HSCT) stands a better chance in their own ethnic group. This information led many nations to establish unrelated stem cell donor registries. We started our Saudi Stem Cell Donor registry (SSCDR) in 2011. The calculated donor pool size was nearly 1 million donors to find a matched donor for every patient. So far we have recruited 75,145 donors. In this exercise we attempted to investigate the chances of finding a matched donor for Saudi patients in need of HSCT. A total of 445 patients were recruited for this study. Donor searches were carried out locally and internationally using Prometheus software and World Marrow Donor Association Search and Match Service, respectively. Only 24% of the patients found a matched donor in our registry, 12% found a donor in other registries, making it a total of 36% of our patients who have the chance to find a full 10/10 HLA-matched donor. However, when we included 9/10 and 8/10 with the full matched donors, the chances go up to 83%. The top scoring registries for number of patients finding 10/10 matched donors were SSCDR (108), Deutsche Stammzellspenderdatei Nabelschnurblut (n = 52), King Faisal Specialist Hospital & Research Centre Stem Cell Donor Registry (n = 52), NMDP-National Marrow Donor Program/Be The Match (n = 43), TURKOK-Turkish Stem Cell Coordination Centre (n = 39), DKMS United Kingdom (n = 24), and Ezer Mizion Bone Marrow Donor Registry (n = 20). The patient who found the highest number of donors in international registries carried the European haplotype A1-B8-DR3; a total of 272 donors were found, and none of them were from our registry. Patients with the highest matched donor numbers in SSCDR carried haplotypes that were not common in international registries. Having a local registry increases the chances of finding a matched donor for our patients; however, international registries can still add to the chances of finding matched donors. Increasing our donor pool will increase chances of our patients finding a matched donor.

Inflammatory Response and Phenotyping in Severe Acute Respiratory Infection From the Middle East Respiratory Syndrome Coronavirus and Other Etiologies.

OBJECTIVES: In this study, we evaluated the inflammatory response in patients with severe acute respiratory infection due to the Middle East respiratory syndrome and non-Middle East respiratory syndrome and assessed the presence of distinct inflammatory subphenotypes using latent class analysis. DESIGN: Prospective cohort study. SETTING: A tertiary care ICU in Riyadh, Saudi Arabia. PATIENTS: Consecutive critically ill patients with laboratory-confirmed Middle East respiratory syndrome severe acute respiratory infection and non-Middle East respiratory syndrome severe acute respiratory infection. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: We measured cytokines on days 1, 3, 7, and 14 of ICU stay. We included 116 patients (40 with Middle East respiratory syndrome severe acute respiratory infection and 76 with non-Middle East respiratory syndrome severe acute respiratory infection). On ICU day 1, both patients with Middle East respiratory syndrome severe acute respiratory infection and non-Middle East respiratory syndrome severe acute respiratory infection had higher levels of interleukin-3, interleukin-4, interleukin-6, interleukin-8, interleukin-17A, eotaxin, and epidermal growth factor compared with healthy controls. There were no differences in cytokines over time between patients with Middle East respiratory syndrome severe acute respiratory infection and non-Middle East respiratory syndrome severe acute respiratory infection. Using day 1 cytokine levels, latent class analysis categorized patients into two subphenotypes: subphenotype 1 (n = 74 [64%]) and subphenotype 2 (n = 42 [36%]); the latter had significantly higher levels of interleukin-1ß, interleukin-1ra, interleukin-2, interleukin-6, interleukin-7, interleukin-8, interleukin-10, interleukin-12p70, interleukin-15, interleukin-17A, inducible protein-10, monocyte chemoattractant protein-1, macrophage inflammatory protein-1α, macrophage inflammatory protein-1ß, tumor necrosis factor-α, granulocyte-macrophage colony-stimulating factor, granulocyte-colony stimulating factor, interferon-α, and interferon-γ. Although baseline characteristics were not different between the two subphenotypes, patients in the subphenotype 2 had higher ICU mortality compared with the subphenotype 1 (18/42 [43%] vs 17/74 [23%]; p = 0.03). CONCLUSIONS: One third of critically ill patients with Middle East respiratory syndrome severe acute respiratory infection and non-Middle East respiratory syndrome severe acute respiratory infection demonstrated a subphenotype characterized by increased proinflammatory cytokines, consistent with cytokine storm. Further research is needed to examine whether immunomodulators have differential effects based on inflammatory subphenotypes.

HLA-A, -B, -C, -DRB1, -DQB1, and -DPB1 Allele and Haplotype Frequencies of 28,927 Saudi Stem Cell Donors Typed by Next-Generation Sequencing.

Human leukocyte antigen (HLA) allele and haplotype frequency distribution varies widely between different ethnicities and geographical areas. Matching for HLA alleles is essential for successful related and unrelated stem cell transplantation. Among the Saudi population, data on HLA alleles and haplotypes are limited. A cross-sectional study was performed on 28,927 bone marrow donors. The most frequent HLA alleles were HLA-A*02:01:01G (20.2%), A*24:02:01G (7.5%); B*51:01:01G (19.0%), B*50:01:01G (12.3%); C*06:02:01G (16.7%), C*07:02:01G (12.2%); DRB1*07:01:01 (15.7%), DRB1*03:01:01G (13.3%); DQB1*02:01:01G (29.9%), DQB1*03:02:01G (13.2%); and DPB1*04:01:01G (35.2%), DPB1*02:01:02G (21.8%). The most frequent HLA-A~C~B~DRB1~DQB1 haplotypes were A*02:01:01G~C*06:02:01G~B*50:01:01G~DRB1*07:01:01G~DQB1*02:01:01G (1.9%) and A*02:05:01G~C*06:02:01G~B*50:01:01G~DRB1*07:01:01G~DQB1*02:01:01G (1.6%). The most frequent HLA-A~C~B~DRB1~DQB1~DPB1 haplotypes were A*02:01:01G~C*15:02:01G~B*51:01:01G~DRB1*04:02~DQB1*03:02:01G~DPB1*04:01:0G (1%) and A*02:01:01G~C*07:02:01G~B*07:02:01G~DRB1*15:01:01G~DQB1*06:02:01G~ DPB1*04:01:01G (0.9%). Based on these haplotype frequencies, we provide forecasts for the fraction of patients with full matching and single mismatched donors for 3 to 6 loci depending on the registry size. With one million donors, about 50% of the patients would find an 8/8 match and 90% a 7/8 match. These data are essential for registry planning, finding unrelated stem cell donors, population genetic studies, and HLA disease associations.

Screening for pre-leukemia TEL-AML1 chromosomal translocation in banked cord blood units: cord blood bank perspective.

Acute lymphocytic leukemia is the most common leukemia in children. Many studies suggest the existence of two subsequent hits in order for the disease to occur. TEL-AML1 (ETV6-RUNX1) is considered an initial genetic hit that occurs prenatally and generates a pre-leukemia clone. In cord blood (CB) stem cell transplantation, donor cell leukemia (DCL) is one of the complications associated with the presence of the pre-leukemic clone. The aim of this study was to identify the prevalence of ETV6-RUNX1 translocation in CB units and the feasibility in implementing such a screening test, to ensure the safety of the CB units. A total of 424 CB samples were tested from the CB units banked at KAIMRC-CBB. RNA was extracted and cDNA synthesis was performed on 1 ug input RNA using Reverse Transcriptase RT-PCR methodology. Chromosomal translocation ETV6-RUNX1 was tested using real time quantitative PCR methodology. Our study showed undetectable levels of ETV6-RUNX1 in all tested CB samples. The samples were analyzed for the chromosomal translocation ETV6-RUNX1 under controlled conditions, using control and fusion genes with known concentrations. The result of this study does not rule out the importance of this screening test in predicting and/or preventing DCL. Moreover, the outcome strengthens the adopted system in our CBB for mother medical history screening prior to donation. We propose adding this test during the verification testing stage, prior to the release of CB units selected for transplantation rather than at the banking stage.

Real-World Issues and Potential Solutions in Hematopoietic Cell Transplantation during the COVID-19 Pandemic: Perspectives from the Worldwide Network for Blood and Marrow Transplantation and Center for International Blood and Marrow Transplant Research Health Services and International Studies Committee.

The current COVID-19 pandemic, caused by SARS-CoV-2, has impacted many facets of hematopoietic cell transplantation (HCT) in both developed and developing countries. Realizing the challenges as a result of this pandemic affecting the daily practice of the HCT centers and the recognition of the variability in practice worldwide, the Worldwide Network for Blood and Marrow Transplantation (WBMT) and the Center for International Blood and Marrow Transplant Research's (CIBMTR) Health Services and International Studies Committee have jointly produced an expert opinion statement as a general guide to deal with certain aspects of HCT, including diagnostics for SARS-CoV-2 in HCT recipient, pre- and post-HCT management, donor issues, medical tourism, and facilities management. During these crucial times, which may last for months or years, the HCT community must reorganize to proceed with transplantation activity in those patients who urgently require it, albeit with extreme caution. This shared knowledge may be of value to the HCT community in the absence of high-quality evidence-based medicine. © 2020 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Common, intermediate and well-documented HLA alleles in world populations: CIWD version 3.0.0.

A catalog of common, intermediate and well-documented (CIWD) HLA-A, -B, -C, -DRB1, -DRB3, -DRB4, -DRB5, -DQB1 and -DPB1 alleles has been compiled from over 8 million individuals using data from 20 unrelated hematopoietic stem cell volunteer donor registries. Individuals are divided into seven geographic/ancestral/ethnic groups and data are summarized for each group and for the total population. P (two-field) and G group assignments are divided into one of four frequency categories: common (≥1 in 10 000), intermediate (≥1 in 100 000), well-documented (≥5 occurrences) or not-CIWD. Overall 26% of alleles in IPD-IMGT/HLA version 3.31.0 at P group resolution fall into the three CIWD categories. The two-field catalog includes 18% (n = 545) common, 17% (n = 513) intermediate, and 65% (n = 1997) well-documented alleles. Full-field allele frequency data are provided but are limited in value by the variations in resolution used by the registries. A recommended CIWD list is based on the most frequent category in the total or any of the seven geographic/ancestral/ethnic groups. Data are also provided so users can compile a catalog specific to the population groups that they serve. Comparisons are made to three previous CWD reports representing more limited population groups. This catalog, CIWD version 3.0.0, is a step closer to the collection of global HLA frequencies and to a clearer view of HLA diversity in the human population as a whole.

HLA-A, B, C, DRB1 and DQB1 allele and haplotype frequencies in volunteer bone marrow donors from Eastern Region of Saudi Arabia.

We analyzed HLA allele and haplotype frequencies from donors from the Eastern region of Saudi Arabia. A cross-sectional study was performed on 2405 bone marrow donors from the Eastern region. HLA typing was carried out by sequencing. The most common HLA allele groups were HLA-A*02:01:01G (11.08%), A*01:01:01G (10.40%), HLA-B*52:01:01G (8.79%), B*18:01:01G (8.07%), HLA-C*04:01:01G (17.88%), C*12:03:01G (10.23%), HLA-DRB1*10:01 (14.89%), DRB1*03:01:01G (14.10%), HLA-DQB1*02:01:01G (24.53%) and DQB1*05:01:01G (20.17%). The most frequent HLA-A~ C~ B~ DRB1~ DQB1 haplotypes were HLA-A*01:03~ C*15:05:01G~ B*73:01~ DRB1*10:01:01~ DQB1*05:01:01G (3.11%) and HLA-A*01:01:01G~ C*12:02:01G~ B*52:01:01G~ DRB1*15:02:01~ DQB1*06:01:01G (2.25%). When comparing the allele and haplotype frequencies of the Eastern regions' population to those from the Central region we found significant differences in several allele frequencies including A*01:01:01G (P ≤ 0.0001), B*52:01:01G (P ≤ 0.0001), B*18:01:01G (P = 0.0001), C*12:03:01G (P < 0.0001), DRB1*10:01:01 (P < 0.0001) and DQB1*05:01:01G (P < 0.0001). Our data confirms genetic heterogeneity among the Saudi population.

Decidua Basalis Mesenchymal Stem Cells Favor Inflammatory M1 Macrophage Differentiation In Vitro.

Placental mesenchymal stem cells from maternal decidua basalis tissue (DBMSCs) are promising cells for tissue repair because of their multilineage differentiation and ability to protect endothelial cells from injury. Here, we examined DBMSC interaction with macrophages and whether this interaction could modulate the characteristics and functions of these macrophages. We induced monocytes to differentiate into M1-like macrophages in the presence of DBMSCs. DBMSC effects on differentiation were evaluated using microscopy, flow cytometry, and ELISA. DBMSC effects on M1-like macrophage induction of T cell function were also examined. The culture of DBMSCs with monocytes did not inhibit monocyte differentiation into M1-like inflammatory macrophages. This was confirmed by the morphological appearance of M1-like macrophages, increased expression of inflammatory molecules, and reduced expression of anti-inflammatory molecules. In addition, DBMSCs did not interfere with M1-like macrophage phagocytic activity; rather, they induced stimulatory effects of M1-like macrophages on CD4⁺ T cell proliferation and subsequent secretion of inflammatory molecules by T cells. We showed that DBMSCs enhanced the differentiation of M1-like inflammatory macrophages, which function as antitumor cells. Therefore, our findings suggest that DBMSCs are inflammatory cells that could be useful in cancer treatment via the enhancement of M1- like macrophages.

Public Awareness on Cord Blood Banking in Saudi Arabia.

BACKGROUND: In the last decade, cord blood (CB) has proven to be a valuable source of hematopoietic stem cells for transplantation to treat many hematological disorders. Since then, many CB banks have been established worldwide. Our aim was to estimate the level of public awareness of CB banking in Saudi Arabia. STUDY DESIGN AND METHODS: A self-administered questionnaire of 22 multiple choices was conveniently distributed, consisting of demographics, awareness measure, attitude toward banking preference, and donation for research data. RESULTS: A total of 1146 participants have completed the questionnaire. The majority were young female 19-25 years old (26%), who are college graduates (57%) with middle class socioeconomic status (82%). The subjective assessment of the overall knowledge was inadequate (66%). For the objective assessment, 12 questions were asked about CB source, collection, storage, and usage. Only half of the subjects (52%) knew that CB is a source of stem cells. More than half did not know the main use of CB. About half did not know about the method of collection nor the condition of storing. CONCLUSION: This study shows a high lack of knowledge about CB banking. More than half of the subjects were unaware of CB banking and its uses. However, most subjects are accepting CB storage, which anticipates great impact and efficacy on educational programs. Moreover, the data demonstrated that health professionals were not the source of knowledge. We recommend having comprehensive educational campaigns with clear information about CB banking to facilitate positive perspectives towards donation and scientific research.

Umbilical Cord Blood Natural Killer Cells, Their Characteristics, and Potential Clinical Applications.

Natural killer (NK) cells are lymphocytes of the innate immune system able to kill different targets such as cancer cells and virally infected cells without prior activation making then attractive candidates for cancer immunotherapy. Umbilical cord blood (UCB) has become a source of hematopoietic stem cells for transplantation but as we gain a better understanding of the characteristics of each immune cell that UCB contains, we will also be able to develop new cell therapies for cancer. In this review, we present what is currently known of the phenotype and functions of UCB NK cells and how these cells could be used in the future for cancer immunotherapy.

Factor predicting total nucleated cell counts in cord blood units.

BACKGROUND: Cord blood (CB) stem cells have been used worldwide in transplant medicine to treat various diseases. The efficacy of stem cells in umbilical CB (UCB) can be predicted by the number of total nucleated cells (TNCs). To optimize the clinical use of stem cells in our population, this study addresses several variables affecting the TNC count. STUDY DESIGN AND METHODS: This observational, cross-sectional study was conducted in a single center from 2012 to 2014. In total, 957 CB units (CBUs) were collected from consented mothers. Data analyses of clinically accepted CBUs were correlated with maternal and infant factors. RESULTS: Based on the TNC accepted level of banking, 188 CBUs (19.64%) were rejected. Of the 16 maternal and infant variables evaluated, three factors demonstrated a statistically significant predictive value for the accepted TNC level. CB volume was the best predictive factor (p ≤ 0.0001), followed by newborn birth weight (p = 0.025), and the method of delivery (p = 0.002). CONCLUSIONS: Several maternal, neonatal, and obstetric factors appear to play a major role in predicting an accepted TNC count, which can be used to improve criteria for the donation of stem cells in CBUs.

Screening panel-reactive antibody negative, single-antigen positive: a case report.

Sensitized patients remain a challenge for successful transplant. Virtual crossmatch is used to determine the presence or absence of donor-specific antibodies. A 60-year-old woman with a negative screening for panel-reactive antibodies (PRA) received an A*11, A*68 type kidney with a negative anti-human globulin/complement-dependent cytotoxicity (AHG-CDC) crossmatch. Her transplant course was complicated by delayed graft function, and she required hemodialysis. On day 8 after receiving the transplant, she had a kidney biopsy that showed features of antibody-mediated rejection/severe acute tubular necrosis, which was treated by plasmapheresis for 5 sessions and intravenous immunoglobulin (2 g/kg). Her serum level of creatinine decreased from 6.7 to 3.6 mg/dL (600-320 µmol/L). Panel-reactive antibody by Luminex was repeated and again was negative. Single-antigen detection was tried next. Surprisingly, A*11:02 came up positive with a mean fluorescence intensity of 9500. High-resolution donor HLA type was A*68:01 and A*11:01. A*11:02 is not part of the screening Luminex PRA whereas the 11:01 allele is. Serologically, HLA-A11 has 2 defined splits, A11.1 and A11.2, which encode A*11:01 and A*11:02, respectively. In this case, the A*11:02 antibody does not seem to be responsible for the increasing creatinine level. However, if the donor had been A*11:02, a humeral rejection would have occurred and been missed by a virtual crossmatch. Thus virtual crossmatch may not work at all times. Screening for PRA by single antigens is suggested even in PRA-negative cases, if only virtual crossmatch is to be used.

Stem cell research and regenerative medicine at King Abdullah International Medical Research Center.

Translation of stem cell research from bench to bedside opens up exciting new therapeutic options for patients. Although stem cell research has progressed rapidly, its clinical applications have not kept pace. We report on the establishment of a stem cell research and regenerative medicine program at King Abdullah International Medical Research Center (KAIMRC). The purpose of this unit is to coordinate advanced stem cell research and translational outcomes with the goal of treating chronic human diseases, such as cancer, diabetes, cardiovascular, neurological, immunological, and liver diseases. Our first step in achieving this goal was to integrate the stem cells and regenerative medicine unit with our umbilical cord blood bank and bone marrow registry. This organizational structure will provide different sources for stem cells for research and clinical purposes, and facilitate our stem cell research and stem cell transplantation program. We are at an early and exciting stage in our program, but we believe that our progress to the international stage will be rapid and have a significant impact.

HLA-C polymorphisms in two cohorts of donors for bone marrow transplantation.

The typing for HLA-C in transplantation was rather neglected in the past. However, several recent studies have emphasized its role in transplantation and its association with the outcome. Serological typing of HLA-C could identify only a limited number of HLA-C antigens, resulting in a number of HLA-C blanks. This was mainly due to the low expression of surface HLA-C and the small number of available specific anti-sera. Performing molecular methods has identified new HLA-C alleles and filled the blank of most serological typed antigens. In this study, we compared serological and molecular typing of HLA-C in two cohorts of healthy Saudis. Our serological typing method identified HLA-C1-7 with different frequencies, 23.5% of the alleles were not identified and thus defined as blank. Using the SSP molecular method, all samples were typed and all alleles were defined. Both methods showed that C∗07 and C∗06 have the highest frequency in the Saudi population. Our study emphasizes the importance of molecular methods in identifying all possible HLA-C alleles.

Monoclonal gammopathy in a tertiary referral hospital.

OBJECTIVE: Monoclonal gammopathies reflect conditions of plasma B-cell disorders. Our objective was to identify the prevalence and types of these gammopathies in our population. METHODS: A 10year retrospective study was conducted. Serum and/or urine protein electrophoresis were performed on 6624 samples. Positive bands were further tested by immunofixation (IFE). RESULTS: Homogenous bands were detected in 7% of the patients. IFE method confirmed 6.3% in which 59% were males and 41% were females. The mean age was 64.7 for females and 66.5 for males. The sensitivity and specificity were 91% and 99% respectively. The most common protein was IgG kappa 41%, followed by IgG lambda 19%. Sixty-eight percent of these patients had monoclonal gammopathy of undetermined significance and 14.6% had multiple myeloma. CONCLUSION: The majority of the studied population had MGUS. This observation is in concord with other western populations. The sensitivity and specificity of protein electrophoresis is diagnostically and reasonably acceptable.

Mast cells, histamine, and IL-6 regulate the selective influx of dendritic cell subsets into an inflamed lymph node.

In response to bacterial stimuli, multiple dendritic cell (DC) populations accumulate within the draining lymph node, thus enhancing opportunities for effective T cell-DC interaction. DC subpopulations, such as plasmacytoid, CD8(+), and CD11b(+) subsets, have distinct roles in determining the nature of the immune response. The mechanisms whereby individual DC subpopulations are mobilized and the extent to which these processes are linked to increases in overall lymph node cellularity have not been determined. In the current study, the mechanisms of DC subset mobilization to the draining auricular lymph node were examined after intradermal injection of Staphylococcus aureus-derived peptidoglycan. Using mast cell-deficient mice and local mast cell reconstitution, plasmacytoid and CD8(+) DC responses were shown to be mast cell dependent, whereas the CD11b(+) DC response was not. A histamine H2 receptor-dependent, CXCL9-independent pathway controlled the selective influx of both plasmacytoid and CD11b(+) DC into the lymph node, but not lymph node cellularity. In contrast, IL-6 was important for the mobilization of CD8(+) and CD11b(+) DC. TNF and IL-1 receptor were dispensable for plasmacytoid, CD11b(+), and CD8(+) DC responses. These findings provide novel opportunities for the selective mobilization of specific DC subsets to lymph nodes and demonstrate critical roles for both histamine and IL-6 in this process.