Predicting Stage Progression in Binet Stage a Chronic Lymphocytic Leukemia.

INTRODUCTION: The variable clinical course of chronic lymphocytic leukemia (CLL) and the lack of consensus on follow-up and treatment strategies have necessitated a prognostic model for identifying high-risk patients at the time of diagnosis. METHODS: We involved a retrospective analysis of demographic and clinical characteristics of 212 patients diagnosed with Binet stage A CLL and thus eligible for risk stratification by both the International Prognostic Score for Early-stage CLL (IPS-E) and the alternative IPS-E (AIPS-E). We evaluated the applicability of these prognostic indices in our young, Middle Eastern cohort (median age 59 at diagnosis). RESULTS: During the study period with a median follow-up of 3.5 years, 67 patients (32 %) experienced progression to first treatment and cumulative incidence of treatment was 13 % at 1 year and 28 % at 3 years after diagnosis. Sixty-nine (51 % of the 136 with a known value) patients harbored an unmutated immunoglobulin heavy chain gene (IGHV) and 21 (10 %) an 11q or 17p deletion with 11 % lacking FISH results. For each early-stage CLL prognostic index, more patients were identified as high-risk for disease progression (51 % of 124 patients evaluable for IPS-E; 42 % of 109 patients evaluable for AIPS-E) than intermediate-risk and low-risk. Multivariable models involving the IPS-E and AIPS-E components revealed that unmutated IGHV and elevated absolute lymphocyte count were significant predictors of earlier treatment requirement. Both prognostic scores were discriminative of time to first treatment (log-rank p < 0.001; c-statistics of 0.74 for IPS-E and 0.69 for AIPS-E). CONCLUSION: Although clarity on clinical behavior with regard to initiation of treatment remains elusive, IPS-E and AIPS-E are valuable tools for identifying high-risk patients.

Evidence-based Management of Chronic Lymphocytic Leukemia: Consensus Statements from the Gulf Region.

INTRODUCTION: Despite recent advances in diagnosis, prognostication, and treatment options, chronic lymphocytic leukemia (CLL) is still a largely incurable disease. New concepts on diagnosis, staging, treatment, and follow-up on CLL have been incorporated throughout recent years. The lack of regional consensus guidelines has led to varying practices in the management of patients with CLL in the region. AIM: This manuscript aims to reach a consensus among expert hematologists regarding the definitions, classifications, and related practices of CLL. The experts developed a set of statements utilizing their personal experience together with the current literature on CLL management. This consensus aims to provide guidance for healthcare professionals involved in the management of CLL and serves as a step in developing regional guidelines. METHODS: Eight experts responded to 50 statements regarding the diagnosis, staging, treatment, and prognosis of CLL with three potential answering alternatives ranging between agree, disagree, and abstain. This consensus adopted a modified Delphi consensus methodology. A consensus was reached when at least 75% of the agreement to the answer were reached. This manuscript presents the scientific insights of the participating attendees, panel discussions, and the supporting literature review. RESULTS: Of the 50 statements, a consensus was reached on almost all statements. Statements covered CLL-related topics, including diagnostic evaluation, staging, risk assessment, different patient profiles, prognostic evaluation, treatment decision, therapy sequences, response evaluation, complications, and CLL during the COVID-19 pandemic. DISCUSSION/CONCLUSION: In recent years, CLL management has progressed significantly with many diagnostic tests and several novel treatments becoming available. This consensus gathers decades of consolidated principles, novel research, and promising prospects for the management of this disease.

Evaluation of the CLL-IPI and IPS-E Prognostic Indices in a Young Middle Eastern Population with Chronic Lymphocytic Leukemia: A Retrospective Analysis at the Kuwait Cancer Control Center.

INTRODUCTION: The Chronic Lymphocytic Leukemia International Prognostic Index (CLL-IPI) is a powerful prognostic tool validated in multiple Western populations. However, its utility in the young Middle Eastern population is unknown. METHODOLOGY: We conducted a retrospective analysis of 152 unselected patients with chronic lymphocytic leukemia (CLL) diagnosed between 2008 and 2022 at the Kuwait Cancer Control Center, which serves as the sole cancer center in Kuwait. The evaluation of the CLL-IPI was based on the assessment of event-free survival (EFS) across the entire cohort. Subsequently, we compared the CLL-IPI with the International Prognostic Score for Early-stage patients (IPS-E) in order to predict the time to first treatment specifically within the subgroup of patients diagnosed with early-stage disease. RESULTS: The median age of the study cohort was 59.9 years (IQR, 53.1-68.8). The 5-year EFS rates for the low, intermediate, and high/very high-risk categories were approximately 82%, 34%, and 23%, respectively, p < 0.001 (C-statistic = 0.67). On multivariate analysis, advanced stage and unmated IGHV status were independent prognostic factors of EFS. In those with early-stage disease, cumulative 5-year treatment incidence rates for the low, intermediate, and high/very high-risk categories based on the CLL-IPI score were approximately 8%, 55%, and 55%, respectively, p = 0.001 (C-statistic = 0.70). However, based on the IPS-E score, the cumulative 5-year treatment incidence rates for the low, intermediate, and high-risk categories were approximately 0%, 10%, and 60%, respectively, p < 0.001 (C-statistic = 0.73). CONCLUSIONS: The CLL-IPI and the IPS-E are valid stratification tool in our young Middle Eastern population.

Epidemiology of de novo Acute Myeloid Leukemia in Kuwait per the 2016 WHO Classification.

OBJECTIVE: Acute myeloid leukemia (AML) is a hematological malignancy that arises from the clonal proliferation of immature myeloid cells. Although the number of AML cases has dramatically increased worldwide, information on its prevalence and incidence in Kuwait is lacking. This study reports the incidence of AML and patient demographics in the country from 2014 to 2020, based on the 2016 WHO classification of AML. SUBJECTS AND METHODS: Data on patients with AML, including acute promyelocytic leukemia (APL), were collected from a clinical cohort with 281 cases analyzed in this study. RESULTS: The overall median age of the population was 47 years with a 1.1:1 male-to-female ratio. Over the study period, the incidence of AML demonstrated a general increasing trend, with the highest and lowest overall incidence occurring in 2018 and 2015, respectively. The frequency of APL in our cohort was 8.9%. Regarding the 2017 European LeukemiaNet (ELN) risk stratification of patients with AML, 37%, 46%, and 17% of patients had a favorable, intermediate, and adverse risk, respectively. A total of 57% of cases achieved complete remission post-induction, and the median overall survival was 37 months. CONCLUSION: Our study may help predict the future trends of AML in Kuwait to help improve clinical management and patient outcomes.

Chronic lymphocytic leukemia in a young population.

INTRODUCTION: Chronic lymphocytic leukemia (CLL) is uncommon in the Middle East. There is limited data on the prognosis and of CLL in this region. METHODS: This was a retrospective study (2009-2020) of consecutively diagnosed patients with CLL at Kuwait Cancer Center. The diagnosis, prognosis, treatment indication, response criteria, and adverse events were recorded per International Workshop on Chronic Lymphocytic Leukemia guidelines. RESULTS: A total of 219 patients with CLL were enrolled in the study. The crude annual incidence is 0.4 per 100,000. The median follow-up was 120 months. The median age at diagnosis was 59 years, and 32 % of patients with CLL were ≤ 55 years of age. Prognostic fluorescence in situ hybridization data were available in 213 cases. del (13q14/13q34) was found in 80 (31 %) cases, del (11q) in 23 (10.7 %) cases, del (17p) in 11 (5.16 %) cases, and trisomy 12 in 46 (21.5 %) cases. IGHV mutation status was available in 92 cases, 45 of which (48.9) were mutated and 47 (51.1 %) of which were not. The median progression-free survival (PFS) for the entire cohort was 178 months [95 % CI: 145-NE].· The median OS was 203 months [95 % CI: 145-NE]. The median PFS for the IGHV mutated cases was not reached [95 % CI: 178 - NE]; while the median PFS for the unmutated CLL cases was 24 months [95 % CI: 124 - NE]. CONCLUSION: CLL is a rare hematological malignancy in the Middle East. Our CLL cohort is younger and expresses less del13q, but has similar rates of IGHV mutations.

Prognosis and Outcome of Fit Patients with Acute Myeloid Leukemia in Kuwait.

PURPOSE: Acute myeloid leukemia (AML) data from the Middle East are limited to single-center studies. We report leukemia-free survival (LFS) and overall survival (OS) of young (≤70 years) patients with AML treated in Kuwait. PATIENTS AND METHODS: This study investigated prognostic markers among 172 young and fit patients with de novo nonacute promyelocytic leukemia AML treated with intensive induction protocols from a tertiary cancer center. RESULTS: The median age was 44 years (interquartile range, 32-51) and 67% of cases were Arab. A greater proportion of males was found in the 2017 European Leukemia Net-defined unfavorable-risk group (20% vs 9%, respectively; P = .02). Most patients (94%) were treated by a standard 7 × 3 regimen; 72.5% of cases achieved complete remission. The 24-month LFS was 44% (95% confidence interval, 30-65), 36% (95% confidence interval, 26-50), and 23% (95% confidence interval, 10-53) for the favorable-, intermediate-, and adverse-risk groups, respectively (P = .018). The 24-month OS was 70% (95% confidence interval, 60-90), 65% (95% confidence interval, 53-79), and 49% (95% confidence interval, 31-78), respectively (P = .05). Multivariable factor analysis identified male gender (hazard ratio [HR], 1.66; P = .029) and older age (HR, 1.02; P = .05) with poor LFS outcome, whereas favorable-risk classification predicated better outcome (HR, 0.49; P = .03). Favorable-risk classification was the only predictor of OS (HR, 0.39; P = .029). CONCLUSION: Fit patients with AML in the favorable-risk group treated with intensive chemotherapy fare well, whereas patients in the adverse-risk group have poor survival.

Association analysis of genetic variants in the ghrelin and tumor necrosis factor α genes and the risk for non-Hodgkin's lymphoma in Kuwaitis.

BACKGROUND: Non-Hodgkin's lymphoma (NHL) is the most common hematological malignancy in the world. Many etiologic factors have been implicated in the risk of developing NHL, including genetic susceptibility and obesity. Single-nucleotide polymorphisms (SNPs) in Ghrelin (GHRL), an anti-inflammatory hormone, and tumor necrosis factor α (TNF-α), an inflammatory cytokine, have been independently associated with the risk for obesity and NHL. OBJECTIVE: To investigate the association between SNPs in GHRL and TNF-α and the risk for NHL and obesity in Kuwaitis. METHODS: We recruited 154 Kuwaiti NHL patients and 217 controls. Genotyping was performed for rs1629816 (GHRL promoter region), rs35684 (GHRL 3' untranslated region), and rs1800629 (TNF-α promoter region). Logistic regression analysis was performed to assess the association of the investigated SNPs with NHL and the relationship between the selected SNPs with BMI in each group separately. RESULTS: We show that rs1629816 GG was associated with an increased risk for NHL in our sample (p= 0.0003, OR 1.82; CI: 1.31-2.54). None of the investigated SNPs were associated with obesity, nor was obesity found to be associated with the risk for NHL. CONCLUSIONS: Our study demonstrates an association between rs1629816, a SNP in the GHRL regulatory region, and NHL in Kuwaitis.

Analysis of Common Driver Mutations in Philadelphia-Negative Myeloproliferative Neoplasms.

BACKGROUND: Philadelphia-negative myeloproliferative neoplasms (MPNs) are a group of hematopoietic stem cell disorders that include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). This study examines the driver mutations among patients with MPNs in Kuwait. PATIENTS AND METHODS: This study was a retrospective review of 942 MPN cases with a driver mutation from July 2007 to June 2019 to examine their demographic, clinical, and laboratory attributes. RESULTS: The annual incidence of MPNs is 1.6 per 100,000 persons, and ET is the most common subtype. The median age of our cohort was 55 years, and the patients were predominantly male. We found that the most frequent gene mutation of MPNs in our cohort was the JAK2V617F mutation, which was present in 90% of cases, followed by the CALR exon 9, MPLW515L/K, and JAK2 exon 12 mutations. In our cohort, thrombotic events were observed in 18.7% of cases. CONCLUSION: Although Philadelphia-negative MPNs are rare hematologic malignancies, thrombosis is a relatively common initial presentation. The JAK2V617F mutation was the driver mutation in the majority of patients with MPN.

UPLC-Tandem Mass Spectrometry for Quantification of Busulfan in Human Plasma: Application to Therapeutic Drug Monitoring.

Busulfan (Bu) is an alkylating agent commonly used in preparative regimens for hematologic malignant and non-malignant patients undergoing hematopoietic stem cell transplantation (HSCT). The objective of the present study was to develop an UPLC-MS/MS method for quantification of Bu in human plasma. A total of 55 patients with hematologic malignancies (n = 34) and non- malignancies (n = 21) received myeloablative Bu therapy prior to HSCT. A tandem mass spectrometric method was developed and validated to quantify Bu levels in these patients. The method was fully validated over the concentration range of 25-2000 ng/mL (r > 0.99). The assay method demonstrated good precision and accuracy. Stability studies indicated that the drug was stable in various conditions. Incurred sample reanalysis findings were within acceptable ranges (<15% of the nominal concentration). Based on the 1st dose AUC results, one third of hematologic malignant patients and half of non-malignant patients needed dose adjustment. However, in subsequent doses (5th, 9th, and 13th), 77%, 82% and 82%, respectively, of hematologic malignant patients and 71%, 67% and 86%, respectively, of non-malignant patients achieved the target range of Bu AUC. The suitability of the developed method for routine TDM of Bu in HSCT patients was demonstrated. The study suggests that the pharmacokinetic profile of Bu varies in both groups.

Molecular Pathogenesis and Clinical Significance of Driver Mutations in Primary Myelofibrosis: A Review.

Primary myelofibrosis (PMF) is a rare chronic BCR-ABL1-negative myeloproliferative neoplasm characterized by progressive bone marrow fibrosis, inefficient hematopoiesis, and shortened survival. The clinical manifestations of PMF include splenomegaly, consequent to extramedullary hematopoiesis, pancytopenias, and an array of potentially debilitating constitutional symptoms. The diagnosis is based on bone marrow morphology and clinical criteria. Mutations in the JAK2 (V617F), MPL (W515), and CALR (exon 9 indel) genes are found in approximately 90% of patients whereas the remaining 10% are so-called triple negatives. Activation of the JAK/STAT pathway results in overproduction of abnormal megakaryocytes leading to bone marrow fibrosis. These mutations might be accompanied by other mutations, such as ASXL1. The commonly used prognostication scoring for PMF is based on the International Prognostic Scoring System. The subsequently developed Dynamic International Prognostic Scoring System-plus employs clinical as well as cytogenetic variables. In PMF, CALR mutation is associated with superior survival and ASXL1 with inferior outcome. Patients with triple-negative PMF have a higher incidence of leukemic transformation and lower overall survival compared with CALR- or JAK2-mutant patients. The impact of genetic lesions on survival is independent of current prognostic scoring systems. These observations indicate that driver and passenger mutations define distinct disease entities within PMF. Accounting for them is not only relevant to clinical decision-making, but should also be considered in designing clinical trials.

Association of Genetic Polymorphisms in the VKORC1 and CYP2C9 Genes with Warfarin Dosage in a Group of Kuwaiti Individuals.

BACKGROUND AND OBJECTIVE: Warfarin is the most widely prescribed oral anticoagulant worldwide. The narrow therapeutic index and the large variation in the inter-individual dose of warfarin are problematic, since the side effects can be lethal. Single nucleotide polymorphisms (SNP) in CYP2C9 and VKORC1 have been shown to significantly affect warfarin dosage toleration and this effect varies among different populations. We aimed to investigate the effect of these SNPs on warfarin dosage in a sample of Kuwaiti patients. METHODS: Kuwaiti patients who were taking a maintenance dose of warfarin were genotyped for CYP2C9*1, *2 and *3 and VKORC1 rs9923231, rs9934438, rs7294 and rs2884737. The association of these SNPs with the warfarin dose was evaluated. RESULTS: For CYP2C9, the CYP2C9 *1/*1 genotype required a higher dose (5.5 ± 3.3 mg/day) compared to non-*1/*1 (3.3 ± 1.7 mg/day) (p = 0.003). For VKORC1, the daily warfarin dose was significantly different (p = 0.001) among the three genotypes of rs9923231, rs9934438 and rs2884737, with carriers of the wild-type genotype requiring the highest dose compared to variant allele carriers (p ≤ 0.001-0.002). There was no association found between the daily warfarin dose and the rs7294 polymorphism. CONCLUSIONS: Our data showed that individuals carrying the wild-type allele of CYP2C9 or VKORC1 rs9923231, rs9934438 or rs2884737 are less sensitive than individuals with the variant alleles of these SNPs and therefore required a higher daily maintenance dose of warfarin. Our study confirms the association between SNPs in CYP2C9 and VKORC1 and warfarin dose tolerance in Kuwaiti patients.

A missense mutation in TFRC, encoding transferrin receptor 1, causes combined immunodeficiency.

Patients with a combined immunodeficiency characterized by normal numbers but impaired function of T and B cells had a homozygous p.Tyr20His substitution in transferrin receptor 1 (TfR1), encoded by TFRC. The substitution disrupts the TfR1 internalization motif, resulting in defective receptor endocytosis and markedly increased TfR1 expression on the cell surface. Iron citrate rescued the lymphocyte defects, and expression of wild-type but not mutant TfR1 rescued impaired transferrin uptake in patient-derived fibroblasts. Tfrc(Y20H/Y20H) mice recapitulated the immunological defects of patients. Despite the critical role of TfR1 in erythrocyte development and function, patients had only mild anemia and only slightly increased TfR1 expression in erythroid precursors. We show that STEAP3, a metalloreductase expressed in erythroblasts, associates with TfR1 and partially rescues transferrin uptake in patient-derived fibroblasts, suggesting that STEAP3 may provide an accessory TfR1 endocytosis signal that spares patients from severe anemia. These findings demonstrate the importance of TfR1 in adaptive immunity.

The place of death of patients with cancer in Kuwait.

BACKGROUND: The place of death (PoD) has a significant effect on end-of-life care for patients dying of cancer. Little is known about the place of cancer deaths in our region. METHODS: To identify the PoD of patients with cancer in Kuwait, we reviewed the death certificates submitted to the Kuwait Cancer Registry in 2009. RESULTS: Of 611 cancer deaths, 603 (98.7%) died in hospitals and only 6 (1%) patients died at home. More than half (57.3%) of inhospital deaths were in the Kuwait Cancer Control Center. Among those for whom the exact PoD within the hospital was identified (484 patients), 116 (24%) patients died in intensive care units and 12 (2.5%) patients died in emergency rooms. CONCLUSIONS: This almost exclusive inhospital death of patients with cancer in Kuwait is the highest ever reported. Research is needed to identify the reasons behind this pattern of PoD and to explore interventions promoting out-of-hospital death among terminally ill cancer patients in Kuwait.

JAK2V617F allele burden in patients with myeloproliferative neoplasms.

Myeloproliferative neoplasms (MPNs) are clonal malignant diseases that represent a group of conditions including polycythemia vera (PV), essential thrombocythemia (ET), and myelofibrosis (MF). The JAK2-V617F mutation is prevalent in almost all patients with MPNs and has become a valuable biomarker for diagnosis of MPNs. A different allele burden in these entities has long been noticed. The aim of our study was to assess the JAK2 allele burden in our JAK2V617F positive cases and its association with phenotype if any and to select a simple, sensitive assay for use in our clinical molecular diagnostic laboratory. Methodologies reported in this literature include amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and real-time quantitative polymerase chain reaction (RQ-PCR). We analyzed 174 cases by RQ-PCR for the quantification of JAK2V617F were initially screened by ARMS-PCR. We found that V617F allele burden in the entire population of patients was 73 % ranging from 0.97 to 95 %. The median V617F allele burden in PV patients was 40 %, MF was 95 %, and ET was 25 %. ARMS-PCR and RQ-PCR were proven to be sensitive since ARMS-PCR is a qualitative method; it can be used to screen JAK2V617F mutation and RQ-PCR was used to quantify the V617F cells. Our study suggests that JAK2V617F positivity is associated with MPNs, and its allele burden is an excellent diagnostic marker for disease subtypes, prognosis, disease phenotype and complication, and evolution. The data indicates that ARMS-PCR is simple and can be easily performed for the primary screening of JAK2V617F mutation, and RQ-PCR is sensitive enough to detect low mutant allele levels (>10 %), specific enough not to produce false positive results, and can be performed for the JAK2V617F allele burden quantification.

Representation of expatriates among cancer patients in Kuwait and the need for culturally-competent care.

From 2000 to 2007, 11,793 cancer patients received treatment in Kuwait. Non-Kuwaitis accounted for 6,016 (51%) patients. They came from 68 countries, mainly from the World Health Organization Eastern Mediterranean (59%) and South-East Asian (20%) regions. The majority (69%) was from low- and low-middle income countries. Thirty-seven percent were from non-Arabic speaking countries. To provide culturally-competent care for expatriate patients, there is a need to explore the impact of their ethnic, sociocultural, economic, language diversity, and expatriation-related stressors on different aspects of cancer care.

Genotypic and phenotypic differences between nodal and extranodal diffuse large B-Cell lymphomas.

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous group of diseases that have diverse clinical, pathological, and biological features. Here, it is shown that primary nodal and extranodal DLBCLs differ genomically and phenotypically. Using conventional comparative genomic hybridization (CGH), the authors assessed the chromosomal aberrations in 18 nodal, 13 extranodal, and 5 mixed DLBCLs. The results demonstrate significantly distinct chromosomal aberrations exemplified by gains of chromosomal arms 1p, 7p, 12q24.21-12q24.31, and 22q and chromosome X and loss of chromosome 4, 6q, and 18q22.3-23 in extranodal compared with nodal DLBCLs. Nodal DLBCLs showed an increased tendency for 18q amplification and BCL2 protein overexpression compared with extranodal and mixed tumors. Using a panel of five antibodies against GCET1, MUM1, CD10, BCL6, and FOXP1 proteins to subclassify DLBCLs according to the recent Choi algorithm, the authors showed that the genomic profiles observed between the nodal and extranodal DLBCLs were not due to the different proportions of GCB vs ABC in the two groups. Further delineation of these genomic differences was illuminated by the use of high-resolution 21K BAC array CGH performed on 12 independent new cases of extranodal DLBCL. The authors demonstrated for the first time a novel genome and proteome-based signatures that may differentiate the two lymphoma types.

Performance status and deaths among children registered in Kuwait National Primary ImmunoDeficiency Disorders Registry.

Children with primary immunodeficiency disorders (PIDD) have an increased risk of suffering from physical, social, and psychological problems. The aim of this study was to evaluate the performance status and mortality of children with PIDD in Kuwait and to determine the variables and co-morbidities that may affect their performance and risk of death. The data for the children were obtained from Kuwait National Primary Immunodeficiency Disorders Registry describes the patients' characteristics, comorbidities and their treatment regimens. Each patient was scored using the Lansky Play Performance Scale (LPPS), and we evaluated the number of deaths among the children and the effects of different variables on their LPPS scores and mortality. We examined 98 pediatric patients with a mean delay in diagnosis of 21.2 months. Antimicrobial prophylaxis was administered to 57.2% of the patients, whereas intravenous immunoglobulin (IVIG) therapy was used in 44%. Eight patients underwent bone marrow transplants. The mean LPPS score for all the patients was 65.5, and there was a significant disparity in the mean LPPS scores across PIDD categories. Twenty-one patients died. The variables that were found to have a significant effect on both the LPPS score and the risk of death were an age of onset of less than 6 months, a history of CMV infection, parental consanguinity, the use of antimicrobial prophylaxis and IVIG therapy. In conclusion, patients with PIDD have a poor performance status and a high rate of mortality. Early diagnosis and aggressive therapeutic interventions directed at patients with early onset of symptoms and CMV infections can help improve the quality of life of patients with PIDD.

Efficient identification of novel mutations in patients with limb girdle muscular dystrophy.

Limb girdle muscular dystrophy type 2 (LGMD2) is a genetically heterogeneous autosomal recessive disorder caused by mutations in 15 known genes. DNA sequencing of all candidate genes can be expensive and laborious, whereas a selective sequencing approach often fails to provide a molecular diagnosis. We aimed to efficiently identify pathogenic mutations via homozygosity mapping in a population in which the genetics of LGMD2 has not been well characterized. Thirteen consanguineous families containing a proband with LGMD2 were recruited from Saudi Arabia, and for 11 of these families, selected individuals were genotyped at 10,204 single nucleotide polymorphisms. Linkage analysis excluded all but one or two known genes in ten of 11 genotyped families, and haplotype comparisons between families allowed further reduction in the number of candidate genes that were screened. Mutations were identified by DNA sequencing in all 13 families, including five novel mutations in four genes, by sequencing at most two genes per family. One family was reclassified as having a different myopathy based on genetic and clinical data after linkage analysis excluded all known LGMD2 genes. LGMD2 subtypes A and B were notably absent from our sample of patients, indicating that the distribution of LGMD2 mutations in Saudi Arabian families may be different than in other populations. Our data demonstrate that homozygosity mapping in consanguineous pedigrees offers a more efficient means of discovering mutations that cause heterogeneous disorders than comprehensive sequencing of known candidate genes.

Extranodal lymphoma: a comparative study.

BACKGROUND: The incidence of extranodal non-Hodgkin's lymphoma (NHL) is increasing worldwide. The epidemiology of NHL in the Middle East is largely unknown. PATIENTS AND METHODS: We evaluated all cases of NHL diagnosed at our institutions between 1998 and 2003 according to the site of presentation and their classification into primary nodal and primary extranodal NHL using strict criteria. Extranodal cases and early stage primary nodal cases were compared in terms of clinical characteristics and treatment outcomes. RESULTS AND DISCUSSION: There were 422 NHL cases diagnosed between January 1998 and December 2003, among which 97 cases (23%) were primary nodal, 132 (31%) were early nodal, and 193 (46%) were disseminated primary nodal. In general, there was a male preponderance of primary nodal cases (63% versus 44%; p=0.007). There was a higher prevalence of primary nodal cases in Arabs than in Asians: Kuwaiti Arabs, 50%; other Arabs, 46%; and Asians, 11%. There was a different distribution of histologic subtypes between primary nodal and extranodal NHL (p=0.001). The most common histologic subtype among extranodal cases was diffuse large B cell lymphoma, which accounted for 71% (69) of cases. The most common anatomic site involved was the gastrointestinal tract, which accounted for 45% of all cases. The difference in event-free survival between nodal and extranodal low-grade NHL was not statistically significant (p=0.17). Primary nodal high-grade lymphomas show an overall survival than the primary extranodal disease (p=0.003). CONCLUSION: We conclude that extranodal NHL is common among patients of Arabic descent. Diffuse large B cell lymphoma is the most common histologic subtype and often involves the gastrointestinal tract. Patients with aggressive primary extranodal NHL have lower overall survival than patients with early primary nodal disease.

Factors associated with successful mobilization of progenitor hematopoietic stem cells among patients with lymphoid malignancies.

PURPOSE: This study's main aim was to assess the effect of 2 mobilization regimens (granulocyte colony-stimulating factor [G-CSF] and chemotherapy vs. G-CSF alone) on the yield of CD34(+) cells in the apheresis components of patients with lymphoid malignancy. We also sought to identify possible predictors of CD34(+) cell yield in the apheresis components. PATIENTS AND METHODS: CD34(+) cells were mobilized and harvested from 89 patients with non-Hodgkin lymphoma (n = 62) or Hodgkin disease (n = 27). Forty-one patients (46.1%) were mobilized with G-CSF, and 48 (53.9%) were mobilized with chemotherapy and G-CSF. Univariate and multivariate analyses were used to examine potential predictors of the CD34(+) cell yield (collection of > 2.7 x 10(6) cells/kg), such as the number of peripheral CD34(+) cells, age, sex, diagnosis, disease stage, weight, bone marrow status at baseline, mononuclear cells, white blood cells, and platelet counts. RESULTS: The median patient age was 41 years (range, 12-66 years), and the median patient weight was 72 kg (range, 44-123 kg). Mobilization of peripheral blood progenitor cells (PBPCs) was superior when using chemotherapy and G-CSF versus G-CSF alone (3.6 x 10(6) cells/kg vs. 2.2 x 10(6) cells/kg; P = .001). CD34(+) cell counts and platelet counts in the peripheral blood significantly correlated with CD34(+) yield (P < .01 and P = .009, respectively). The yield was also significantly affected by weight, diagnosis, mobilization regimen, and baseline bone marrow status (P = .021, P = .05, P = .002, and P = .043, respectively). CONCLUSION: Many factors influence harvesting of PBPCs, including diagnosis, bone marrow status at baseline, patient weight, and the type of mobilization regimen. The number of CD34(+) cells in the peripheral blood can be used to predict the timing of apheresis and optimize yield.