Novel Presentation of Major Histocompatibility Complex Class II Deficiency with Hemophagocytic Lymphohistiocytosis.

PURPOSE: Major histocompatibility complex (MHC) class II deficiency is one of the combined immune deficiency disorders caused by defects in the MHC class II regulatory genes leading to abnormal T cells development and function. Therefore, patients mainly present with increased susceptibility to infections, diarrhea, and failure to thrive. In this report, we present one MHC class II deficient patient with a novel presentation with Hemophagocytic Lymphohistiocytosis (HLH). METHODS: Immunophenotyping of lymphocyte subpopulations and HLA-DR expression was assess by flow cytometry. Gene mutational analysis was performed by whole exome and Sanger sequencing. RESULTS: We reported a 7-year-old girl, who was diagnosed at age of 2 years with MHC class II deficiency by genetic testing and flow cytometry. Two years later, she developed disseminated BCGitis which was treated with proper antimicrobial agents. At the age of 7 years, she presented with clinical features fulfilling 6 diagnostic criteria of HLH including evidence of hemophagocytic activity in bone marrow aspiration. Accordingly, the diagnosis of HLH was established and the patient was started on IV Dexamethasone, Anakinra and IVIG. Eventually, patient started to improve and was discharged in good condition. Few months later, the patient was readmitted with severe pneumonia and sepsis leading to death. CONCLUSION: Patients with MHC class II deficiency might present with disseminated BCGitis especially if the patient has severe T cell lymphopenia. Additionally, this immune defect might be added to the list of inborn errors of immunity that can be complicated with HLH.

Risk factors predicting disease severity and mortality in coronavirus disease 2019 Saudi Arabian patients.

CONTEXT: Coronavirus disease 2019 (COVID-19) became a global pandemic that may be associated with significant associated risk factors. AIMS: The aim of this study was to evaluate the factors predisposing risk to death in COVID-19 patients. SETTINGS AND DESIGN: This is a retrospective study that presents the demographic, clinical presentation, and laboratory findings on our patients to determine risk factors contributing to their COVID-19 outcome. METHODS: We used logistic regression (odds ratios) to examine associations between clinical findings and risk of death in COVID-19 patients. All analyses were done using STATA 15. RESULTS: A total of 206 COVID-19 patients were investigated, 28 of them died, and 178 survived. Expired patients were older (74.04 ± 14.45 vs. 55.56 ± 18.41 in those who survived) and mainly of male gender (75% vs. 42% in those who survived). The following factors were strong predictors of death: hypertension (OR: 5.48, 95% CI: 2.10-13.59, P < 0.001), cardiac disease (OR: 5.08, 95% CI: 1.88-13.74, P = 0.001), and hospital admission (OR: 39.75, 95% CI: 5.28-299.12, P < 0.001). In addition, blood group B was more frequent in expired patients (OR: 2.27, 95% CI: 0.78-5.95, P = 0.065). CONCLUSIONS: Our work adds to the current knowledge about the factors predisposing to death in COVID-19 patient. In our cohort, expired patients were of older age and male gender plus they were more likely to have hypertension, cardiac disease, and hospital severe disease. These factors might be used to evaluate risk of death in patients recently diagnosed of COVID-19.

Age/BMI is a Stronger Predictor of Death in COVID-19 Patients than Age Alone: A Pilot Study.

The objective of this study was to investigate the effect of age and BMI on the risk of death in patients with coronavirus disease 2019 (COVID-19). A cohort of 206 Saudi COVID-19 patients was included in this study. Data on age, BMI, hospitalization, comorbidities, and death were collected and analyzed. Descriptive, univariate, and multivariate logistic regression analyses were carried out. Out of the 206 studied patients, 28 died. Hypertension, cardiac disease, and hospital admission were predictors of death in univariate and multivariate logistic regression analysis. Moreover, age was a significant predictor of death, while increased BMI seemed to be protective at an older age. Therefore, a new score was suggested taking into consideration both factors, namely age/BMI score. Although older age was associated with death in univariate (OR, 1.09 [95% CI 1.05-1.12], p < 0.001) and multivariate analysis (OR, 1.05 [95% CI 1.02-1.09], p = 0.004), a higher age/BMI score was a stronger predictor of death than age alone, in both univariate (OR 4.42 [95% CI 2.50-7.80], p < 0.001) and multivariate analysis (OR 3.11 [95% CI 1.66-5.82], p < 0.001). Several factors appear to contribute to the risk of COVID-19 death. Interestingly, our new age/BMI score seems to carry a higher risk of death than age alone. This new score will be designated as the Hajeer score. Since this is a small cohort study, we recommend investigating this score in a larger cohort.

Prevalence of Associated Endocrine Diseases in Patients with Neurofibromatosis Type 1.

Background Neurofibromatosis type 1 (NF-1) is an autosomal dominant neurocutaneous disorder that increases the risk of developing benign and malignant tumors. Several associated endocrine diseases in NF-1 patients have been explained in the literature. Thus, this study aims to assess the endocrine manifestations as there no previous local data have discussed this association. Methods A retrospective cross-sectional study was conducted at KAMC and KASCH, Riyadh, Saudi Arabia by including all patients genetically confirmed with NF1 from 2004 until 2019 using a consecutive non-probability sampling technique. The included data were demographics, consanguinity, genetic variant mutations as well as associated endocrine diseases. Results The prevalence of patients with associated endocrine diseases was estimated to be 19.4%. Short stature showed the highest frequency of associated endocrine diseases followed by subclinical hypothyroidism. Positive consanguinity, sporadic mutation, and pathogenic variant showed high frequencies. Conclusion The coexistence of endocrine diseases was found in NF-1 patients. Therefore, screening for endocrine abnormality in patients with NF-1 by comprehensive history and physical exam as well as investigations to minimize complications and the late presentation should be considered; however, further studies are necessary to address the need.

Isolation and Establishment of a Highly Proliferative, Cancer Stem Cell-Like, and Naturally Immortalized Triple-Negative Breast Cancer Cell Line, KAIMRC2.

In vitro studies of a disease are key to any in vivo investigation in understanding the disease and developing new therapy regimens. Immortalized cancer cell lines are the best and easiest model for studying cancer in vitro. Here, we report the establishment of a naturally immortalized highly tumorigenic and triple-negative breast cancer cell line, KAIMRC2. This cell line is derived from a Saudi Arabian female breast cancer patient with invasive ductal carcinoma. Immunocytochemistry showed a significant ratio of the KAIMRC2 cells' expressing key breast epithelial and cancer stem cells (CSCs) markers, including CD47, CD133, CD49f, CD44, and ALDH-1A1. Gene and protein expression analysis showed overexpression of ABC transporter and AKT-PI3Kinase as well as JAK/STAT signaling pathways. In contrast, the absence of the tumor suppressor genes p53 and p73 may explain their high proliferative index. The mice model also confirmed the tumorigenic potential of the KAIMRC2 cell line, and drug tolerance studies revealed few very potent candidates. Our results confirmed an aggressive phenotype with metastatic potential and cancer stem cell-like characteristics of the KAIMR2 cell line. Furthermore, we have also presented potent small molecule inhibitors, especially Ryuvidine, that can be further developed, alone or in synergy with other potent inhibitors, to target multiple cancer-related pathways.

Clinical course of myeloproliferative leukaemia virus oncogene (MPL) mutation-associated familial thrombocytosis: a review of 64 paediatric and adult patients.

Familial thrombocytosis (FT) is a rare hereditary haematological disorder characterised by increased platelet count, usually caused by germ-line mutations in thrombopoietin (THPO), myeloproliferative leukaemia virus oncogene (MPL) or Janus kinase 2 (JAK2) genes, and can be associated with increased risk of thrombosis. We aimed to determine the yield of diagnostic tests, assess treatment received and describe the clinical course of MPL-associated FT. We retrospectively reviewed all paediatric and adult haematology patients diagnosed with MPL-related FT, who were seen in our clinics from March 2013 to February 2021. Of 64 eligible patients, 26 (41%) were aged <14 years, while the remaining 38 (59%) patients were adults. The median (interquartile range) age at diagnosis was 20 (33·5) years. In all, 26 tribes were represented in this cohort of 64 patients, out of which 31 (48%) patients belonged to two tribes. A total of 60 patients (94%) had thrombocytosis on blood count. Additional genetic tests, including myelodysplastic syndrome (MDS) gene panel, Philadelphia gene breakpoint cluster region-Abelson (BCR-ABL) and JAK2, were carried out for 52 patients and only one patient was positive for JAK2 mutation. In all, 21 (33%) patients were prescribed aspirin and seven (11%) were prescribed hydroxyurea. Overall, 63 (98%) patients did not develop any thrombotic or haemorrhagic event. There was no significant association of MPL-mutated FT with thrombosis or haemorrhage.

A novel gene in early childhood diabetes: EDEM2 silencing decreases SLC2A2 and PXD1 expression, leading to impaired insulin secretion.

Monogenic diabetes is a rare type of diabetes resulting from mutations in a single gene. To date, most cases remain genetically unexplained, posing a challenge for accurate diabetes treatment, which leads to on a molecular diagnosis. Therefore, a trio exome scan was performed in a lean, nonsyndromic Caucasian girl with diabetes onset at 2½ years who was negative for autoantibodies. The lean father had diabetes from age 11 years. A novel heterozygous mutation in EDEM2, c.1271G > A; p.Arg424His, was found in the proband and father. Downregulation of Edem2 in rat RIN-m ß-cells resulted in a decrease in insulin genes Ins1 to 67.9% (p = 0.006) and Ins2 to 16.8% (p < 0.001) and reduced insulin secretion by 60.4% (p = 0.0003). Real-time PCR revealed a major disruption of endocrine pancreas-specific genes, including Glut2 and Pxd1, with mRNA suppression to 54% (p < 0.001) and 85.7% (p = 0.01), respectively. No other expression changes related to stress or apoptotic genes were observed. Extended clinical follow-up involving ten family members showed that two healthy individuals carried the same mutation with no sign of diabetes in the clinical screen except for a slight increase in IA-2 antibody in one of them, suggesting incomplete penetrance. In conclusion, we describe EDEM2 as a likely/potential novel diabetes gene, in which inhibition in vitro reduces the expression of ß-cell genes involved in the glucose-stimulated insulin secretion (GSIS) pathway, leading to an overall suppression of insulin secretion but not apoptosis.

Late-onset multiple venous malformations confined to the upper limb: link to somatic MAP3K3 mutations.

Venous (cavernous) malformations are commonly seen in the upper limb. Almost all venous malformations are congenital. They may be sporadic, familial, or syndromic. Late-onset, multiple venous malformations confined to the upper limb are rare. Lesions present after puberty. All previously reported cases were located subcutaneously and were small in size. The condition is non-hereditary and non-syndromic. We present a unique series of eight patients with this rare condition. Unique features included the presence of large malformations (up to 20 cm in diameter) and the presence of subfascial lesions causing nerve compression. Surgical excision was curative. Mutational analysis in one patient identified a novel somatic MAP3K3 gene mutation (c.1723T > C, p.Tyr 575 His) in the affected veins. The encoded MAP3K3 protein is known to accelerate the RAS pathway of cellular proliferation.Level of evidence: IV.

Exome sequencing revealed DNA variants in NCOR1, IGF2BP1, SGLT2 and NEK11 as potential novel causes of ketotic hypoglycemia in children.

Unexplained or idiopathic ketotic hypoglycemia (KH) is the most common type of hypoglycemia in children. The diagnosis is based on the exclusion of routine hormonal and metabolic causes of hypoglycemia. We aimed to identify novel genes that cause KH, as this may lead to a more targeted treatment. Deep phenotyping of ten preschool age at onset KH patients (boys, n = 5; girls, n = 5) was performed followed by trio exome sequencing and comprehensive bioinformatics analysis. Data analysis revealed four novel candidate genes: (1) NCOR1 in a patient with KH, iron deficiency and loose stools; (2) IGF2BP1 in a proband with KH, short stature and delayed bone age; (3) SLC5A2 in a proband with KH, intermittent glucosuria and extremely elevated p-GLP-1; and (4) NEK11 in a proband with ketotic hypoglycemia and liver affliction. These genes are associated with different metabolic processes, such as gluconeogenesis, translational regulation, and glucose transport. In conclusion, WES identified DNA variants in four different genes as potential novel causes of IKH, suggesting that IKH is a heterogeneous disorder that can be split into several novel diseases: NCOR1-KH, IGF2BP1-KH, SGLT2-KH or familial renal glucosuria KH, and NEK11-KH. Precision medicine treatment based on exome sequencing may lead to advances in the management of IKH.

A novel interstitial deletion of chromosome 2q21.1-q23.3: Case report and literature review.

BACKGROUND: Interstitial deletions of 2q are rare. Those that have been reported show varying clinical manifestations according to the size of the deletion and the genomic region involved. METHOD AND RESULTS: We describe a preterm male harboring a novel interstitial deletion encompassing the 2q21.2-q23.3 region of 2q, a deletion that has not been described previously. The patient had multiple congenital anomalies including agenesis of the corpus callosum, congenital cardiac defects, bilateral hydronephrosis, spontaneous intestinal perforation, hypospadias and cryptorchidism, sacral dimple and rocker-bottom feet. Array comparative genomic hybridization (aCGH) analysis revealed a de novo >18 Mb deletion at 2q21.1-q23.3, a region that included (605802, 611472 and 604593) OMIM genes. CONCLUSION: To the best of our knowledge this is the first report of a de novo interstitial deletion at 2q21.1-q23.3 in which haploinsufficiency of dose-sensitive genes is shown to contribute to the patient's phenotype.

De Novo Variants in TAOK1 Cause Neurodevelopmental Disorders.

De novo variants represent a significant cause of neurodevelopmental delay and intellectual disability. A genetic basis can be identified in only half of individuals who have neurodevelopmental disorders (NDDs); this indicates that additional causes need to be elucidated. We compared the frequency of de novo variants in patient-parent trios with (n = 2,030) versus without (n = 2,755) NDDs. We identified de novo variants in TAOK1 (thousand and one [TAO] amino acid kinase 1), which encodes the serine/threonine-protein kinase TAO1, in three individuals with NDDs but not in persons who did not have NDDs. Through further screening and the use of GeneMatcher, five additional individuals with NDDs were found to have de novo variants. All eight variants were absent from gnomAD (Genome Aggregation Database). The variant carriers shared a non-specific phenotype of developmental delay, and six individuals had additional muscular hypotonia. We established a fibroblast line of one mutation carrier, and we demonstrated that reduced mRNA levels of TAOK1 could be increased upon cycloheximide treatment. These results indicate nonsense-mediated mRNA decay. Further, there was neither detectable phosphorylated TAO1 kinase nor phosphorylated tau in these cells, and mitochondrial morphology was altered. Knockdown of the ortholog gene Tao1 (Tao, CG14217) in Drosophila resulted in delayed early development. The majority of the Tao1-knockdown flies did not survive beyond the third instar larval stage. When compared to control flies, Tao1 knockdown flies revealed changed morphology of the ventral nerve cord and the neuromuscular junctions as well as a decreased number of endings (boutons). Furthermore, mitochondria in mutant flies showed altered distribution and decreased size in axons of motor neurons. Thus, we provide compelling evidence that de novo variants in TAOK1 cause NDDs.

Oxidative stress, caloric intake and outcomes of critically ill patients.

BACKGROUND: The aim of this study was to investigate the patterns of oxidative stress in critically ill patients and the association with caloric intake and outcomes. METHODS: In this pre-planned sub-study of the PermiT (Permissive Underfeeding versus Target Enteral Feeding in Adult Critically Ill Patients Trial- ISRCTN68144998), we included patients expected to stay in the ICU for ≥14 days. Serum samples were collected on days 1, 3, 5, 7 and 14 of enrollment. We measured total anti-oxidant capacity (TAC), protein carbonyl concentration (a measure of protein oxidation) and 8-hydroxy-7,8-dihydro-2'-deoxyguanosine (8-OHdG) (a measure of DNA oxidation). We used principal component analysis (PCA) and hierarchical cluster analysis (HCA) to group patients according to oxidative stress. RESULTS: Principal component analysis identified 2 components that were responsible for 79% of the total variance, and cluster analysis grouped patients in three statistically distinct clusters. Majority of patients 78.6% (44/55) were included in cluster 1 with lowest TAC, protein carbonyl and 8-OHdG levels and cluster 2 which accounted for 16.1% (9/55) of patients had the highest levels of TAC and intermediate levels of protein carbonyl levels. Cluster 3 patients 5.4% (3/56) had the highest protein carbonyl levels. Incident renal replacement therapy was highest in cluster 2 (4/8, 50.0%), compared to cluster 1 (4/42, 9.5%) and cluster 3 (1/3, 33.3%, p 0.01). When adjusted to oxidative stress cluster membership, permissive underfeeding was not associated with 90-day mortality (adjusted odds ratio, aOR 1.37, 95% CI 0.36, 5.25, p 0.64) but was associated significantly with lower incident renal replacement therapy (aOR 0.02, 95% CI < 0.001, 0.57, p 0.02). CONCLUSIONS: There are different distinct patterns of oxidative stress in critically ill patients. Incident renal replacement therapy was different among the three clusters. Our data suggest a protective effect of permissive underfeeding on incident renal replacement therapy that may differ by clusters of oxidative stress.

Permissive underfeeding, cytokine profiles and outcomes in critically ill patients.

BACKGROUND: During critical illness in humans, the effects of caloric restriction on the inflammatory response are not well understood. The aim of this study is to examine the associations of caloric restriction, inflammatory response profiles and outcomes in critically ill patients. METHODS: This is a sub-study of the PermiT trial (Permissive Underfeeding or Standard Enteral Feeding in Critically Ill Adults Trial- ISRCTN68144998). Serum samples were collected on study days 1, 3, 5, 7 and 14 and analyzed for a panel of 29 cytokines. We used principal component analysis to convert possibly correlated variables (cytokine levels) into a limited number of linearly uncorrelated variables (principal components). We constructed repeated measures mixed linear models to assess whether permissive underfeeding compared to standard feeding was associated with difference cytokine levels over time. RESULTS: A total of 72 critically ill patients were enrolled in this study (permissive underfeeding n = 36 and standard feeding n = 36). Principal component analysis identified 6 components that were responsible for 78% of the total variance. When adjusted to principal components, permissive underfeeding was not associated with 90-day mortality (adjusted odds ratio 1.75, 95% confidence interval 0.44, 6.95, p = 0.43) or with incident renal replacement therapy. The cytokines did not differ with time between permissive underfeeding and standard feeding groups. CONCLUSIONS: The association of permissive underfeeding compared to standard feeding with mortality was not influenced by the inflammatory profile. Permissive underfeeding compared to standard feeding was not associated with differences in the serum levels of cytokines in critically ill patients.

Proteomic and Molecular Assessment of the Common Saudi Variant in ACADVL Gene Through Mesenchymal Stem Cells.

Very-long-chain acyl-coenzyme A dehydrogenase (VLCAD) is a coenzyme encoded by ACADVL that converts very-long-chain fatty acids into energy. This process is disrupted by c.65C > A; p.Ser22∗ mutation. To clarify mechanisms by which this mutation leads to VLCAD deficiency, we evaluated differences in molecular and cellular functions between mesenchymal stem cells with normal and mutant VLCAD. Saudi Arabia have a high incidence of this form of mutation. Stem cells with mutant VLCAD were isolated from skin of two patients. Metabolic activity and proliferation were evaluated. The Same evaluation was repeated on normal stem cells introduced with same mutation by CRISPR. Mitochondrial depiction was done by electron microscope and proteomic analysis was done on patients' cells. Metabolic activity and proliferation were significantly lower in patients' cells. Introducing the same mutation into normal stem cells resulted in the same defects. We detected mitochondrial abnormalities by electron microscopy in addition to poor wound healing and migration processes in mutant cells. Furthermore, in a proteomic analysis, we identified several upregulated or downregulated proteins related to hypoglycemia, liver disorder, and cardiac and muscle involvement. We concluded experimental assays of mutant ACADVL (c.65C > A; p.Ser22∗) contribute to severe neonatal disorders with hypoglycemia, liver disorder, and cardiac and muscle involvement.

Differential Gene Expression in Peripheral White Blood Cells with Permissive Underfeeding and Standard Feeding in Critically Ill Patients: A Descriptive Sub-study of the PermiT Randomized Controlled Trial.

The effect of short-term caloric restriction on gene expression in critically ill patients has not been studied. In this sub-study of the PermiT trial (Permissive Underfeeding or Standard Enteral Feeding in Critically Ill Adults Trial- ISRCTN68144998), we examined gene expression patterns in peripheral white blood cells (buffy coat) associated with moderate caloric restriction (permissive underfeeding) in critically ill patients compared to standard feeding. Blood samples collected on study day 1 and 14 were subjected to total RNA extraction and gene expression using microarray analysis. We enrolled 50 patients, 25 in each group. Among 1751 tested genes, 332 genes in 12 pathways were found to be significantly upregulated or downregulated between study day 1 and 14 (global p value for the pathway ≤ 0.05). Using the heatmap, the differential expression of genes from day 1 to 14 in the permissive underfeeding group was compared to the standard feeding group. We further compared gene expression signal intensity in permissive underfeeding compared standard feeding by constructing univariate and multivariate linear regression models on individual patient data. We found differential expression of several genes with permissive underfeeding, most notably those related to metabolism, autophagy and other cellular functions, indicating that moderate differences in caloric intake trigger different cellular pathways.

Prevalence of BRCA1 and BRCA2 Mutations Among High-Risk Saudi Patients With Breast Cancer.

Purpose Over the past three decades, the incidence rate of breast cancer (BC) among Arab women has continually increased. However, data on the prevalence of BRCA1/2 mutations are scarce. Although the population in Saudi Arabia is at large homogeneous and consanguinity is common, especially in the central, eastern, and southern regions of the country, the prevalence of BRCA1 and BRCA2 mutations and the characteristics of BC are not well studied in the country. Methods This prospective observational study intended to determine the prevalence of BRCA1 and BRCA2 mutations and sought to examine the clinicopathologic features of BC associated with these mutations. Results Of 310 patients, 270 (87%) had no mutation. BRCA mutations were identified in 40 patients; BRCA1 mutations were found in 11% of patients, and BRCA2 mutations were found in 2% of patients. Variants of unknown significance were found in 15% of patients (45 patients). Triple-negative BC (TNBC) accounted for 86% of all patients with BC and mutations. The following three recurrent deleterious founder BRCA1 mutations were observed: c.4136_4137delCT was observed in five unrelated patients, c.5530delC was observed in three unrelated patients, and c.4524G>A mutations were observed in five unrelated patients. One novel mutation was identified in the BRCA1 gene (c.5512 dup [p.Glu1838Glyfs*42]). Conclusion Among high-risk Saudi patients with BC, BRCA1 mutations are prevalent (11%). TNBC is the most common BC subtype. Furthermore, age alone does not have a significant association with mutation, but a combination of risk factors such as age, familial history, and TNBC has a significant association with BRCA mutation.

KIF16B is a candidate gene for a novel autosomal-recessive intellectual disability syndrome.

Intellectual disability (ID) and global developmental delay are closely related; the latter is reserved for children under the age of 5 years as it is challenging to reliably assess clinical severity in this population. ID is a common condition, with up to 1%-3% of the population being affected and leading to a huge social and economic impact. ID is attributed to genetic abnormalities most of the time; however, the exact role of genetic involvement in ID is yet to be determined. Whole exome sequencing (WES) has gained popularity in the workup for ID, and multiple studies have been published examining the diagnostic yield in identification of the disease-causing variant (16%-55%), with the genetic involvement increasing as intelligence quotient decreases. WES has also accelerated novel disease gene discovery in this field. We identified a novel biallelic variant in the KIF16B gene (NM_024704.4:c.3611T > G) in two brothers that may be the cause of their phenotype.

Coexistence of chronic myeloid leukemia and diffuse large B-cell lymphoma with antecedent chronic lymphocytic leukemia: a case report and review of the literature.

BACKGROUND: Chronic lymphocytic leukemia and chronic myeloid leukemia are the most common types of adult leukemia. However, it is rare for the same patient to suffer from both. Richter's transformation to diffuse large B-cell lymphoma is frequently observed in chronic lymphocytic leukemia. Purine analog therapy and the presence of trisomy 12, and CCND1 gene rearrangement have been linked to increased risk of Richter's transformation. The coexistence of chronic myeloid leukemia and diffuse large B-cell lymphoma in the same patient is extremely rare, with only nine reported cases. Here, we describe the first reported case of concurrent chronic myeloid leukemia and diffuse large B-cell lymphoma in a background of chronic lymphocytic leukemia. CASE PRESENTATION: A 60-year-old Saudi man known to have diabetes, hypertension, and chronic active hepatitis B was diagnosed as having Rai stage II chronic lymphocytic leukemia, with trisomy 12 and rearrangement of the CCND1 gene in December 2012. He required no therapy until January 2016 when he developed significant anemia, thrombocytopenia, and constitutional symptoms. He received six cycles of fludarabine, cyclophosphamide, and rituximab, after which he achieved complete remission. One month later, he presented with progressive leukocytosis (mostly neutrophilia) and splenomegaly. Fluorescence in situ hybridization from bone marrow aspirate was positive for translocation (9;22) and reverse transcription polymerase chain reaction detected BCR-ABL fusion gene consistent with chronic myeloid leukemia. He had no morphologic or immunophenotypic evidence of chronic lymphocytic leukemia at the time. Imatinib, a first-line tyrosine kinase inhibitor, was started. Eight months later, a screening imaging revealed new liver lesions, which were confirmed to be diffuse large B-cell lymphoma. CONCLUSIONS: In chronic lymphocytic leukemia, progressive leukocytosis and splenomegaly caused by emerging chronic myeloid leukemia can be easily overlooked. It is unlikely that chronic myeloid leukemia arose as a result of clonal evolution secondary to fludarabine treatment given the very short interval after receiving fludarabine. It is also unlikely that imatinib contributed to the development of diffuse large B-cell lymphoma; rather, diffuse large B-cell lymphoma arose as a result of Richter's transformation. Fludarabine, trisomy 12, and CCND1 gene rearrangement might have increased the risk of Richter's transformation in this patient.