An intronic FTO variant rs16952570 confers protection against thiopurine-induced myelotoxicities in multiethnic Asian IBD patients.

Thiopurines are used in the treatment of inflammatory bowel disease (IBD) but remain clinically challenging to manage due to wide interpatient variability in clinical outcomes and adverse events. Apart from genetic variants in thiopurine S-methyltransferase (TPMT) and nudix hydrolase 15 (NUDT15) genes, polymorphisms in FTO alpha-ketoglutarate dependent dioxygenase (FTO) were found predictive of thiopurine-induced leukopenia, albeit with conflicting results. To clarify the role of FTO variants in a multiethnic Asian IBD cohort, we recruited 149 patients on thiopurine-based therapy and genotyped two FTO variants p.Ala134Thr (rs79206939) and rs16952570 T > C using Sanger sequencing. FTO p.Ala134Thr (rs79206939) was non-polymorphic and absent whereas intronic rs16952570 T > C was equally prevalent in Chinese (22%) and Indians (18%) and higher in Malays (28%). Higher nadir white blood cell (WBC) and absolute neutrophil count (ANC) levels were observed in patients harboring FTO rs16952570 CC genotypes compared with TT carriers at 4, 8, and 12 weeks after start of thiopurine therapy (P < 0.05). A similar trend was observed in patients carrying the previously well-characterized NUDT15 rs116855232 wild-type CC genotypes. Further in silico analysis suggests that FTO variants linked to rs16952570, particularly rs74018601, may play a regulatory role in altering the FTO expression. The findings from this study indicate a novel protective association with the FTO variant rs16952570 CC genotype and hematological parameters.

NUDT15 R139C causes thiopurine-induced early severe hair loss and leukopenia in Japanese patients with IBD.

The efficacy of thiopurines, including azathioprine (AZA) and 6-mercaptopurine (6MP), has been demonstrated for the treatment of inflammatory bowel disease (IBD). The most common and serious adverse event of treatment with thiopurines altered by doctors is leukopenia. Hair loss is also a serious event that could be a critical reason for patients to decline thiopurine treatment. Thiopurine-induced severe hair loss causes cosmetic problems, and it takes a long time to recover. In a recent study, NUDT15 R139C was strongly associated with thiopurine-induced leukopenia in Korean and Caucasian populations. In this study, we performed an association study to investigate and replicate the association of R139C with adverse events of thiopurines in Japanese patients. A total of 142 Japanese patients with IBD, with histories of thiopurine treatment, were examined. NUDT15 R139C was genotyped using a custom TaqMan genotyping assay. Adverse events including leukopenia were reviewed from medical records. The 6MP dose was adjusted to AZA equivalents by multiplying with 2 as a thiopurine dose. Five patients developed severe hair loss and all of them were risk homozygous (T/T) for R139C. No early severe hair loss was observed in patients with the C/T or C/C genotype (P=3.82 × 10(-16), odds ratio=212). The association of R139C with early (<8 weeks) leukopenia (white blood cells<3000 mm(-3)), which was previously reported in Korean patients, was replicated in our Japanese IBD cohort (P=1.92 × 10(-16), odds ratio=28.4). However, we could not confirm the association with late leukopenia in the Japanese subjects. Patients with the C/T genotype discontinued treatment or required thiopurine dose reduction significantly earlier than patients with the C/C genotype (P=1.45 × 10(-4)); however, on manipulating the doses, there was no significant difference in the thiopurine continuation rates between the groups. In the maintenance period, the frequencies of 6MP usage were higher, and the doses of thiopurines were significantly lower in patients with the C/T genotype than in those with the C/C genotype (0.574±0.316 mg kg(-1) per day vs 1.03±0.425 mg kg(-1) per day, P=6.21 × 10(-4)). NUDT R139C was significantly associated with early severe hair loss in Japanese patients with IBD. We also verified the previously reported association of R139C with early leukopenia in a different East Asian population. It is recommended that treatment with thiopurines should be avoided for patients with the T/T genotype. Low-dose 6MP (0.2-0.3 mg kg(-1) per day) could be used rather than AZA for the patients with C/T genotype to continue thiopurine treatments. However, late leukopenia and other several adverse events could not be completely predicted by R139C genotypes.

The Duffy-null state is associated with a survival advantage in leukopenic HIV-infected persons of African ancestry.

Persons of African ancestry, on average, have lower white blood cell (WBC) counts than those of European descent (ethnic leukopenia), but whether this impacts negatively on HIV-1 disease course remains unknown. Here, in a large natural history cohort of HIV-infected subjects, we show that, although leukopenia (< 4000 WBC/mm(3) during infection) was associated with an accelerated HIV disease course, this effect was more prominent in leukopenic subjects of European than African ancestry. The African-specific -46C/C genotype of Duffy Antigen Receptor for Chemokines (DARC) confers the malaria-resisting, Duffy-null phenotype, and we found that the recently described association of this genotype with ethnic leukopenia extends to HIV-infected African Americans (AAs). The association of Duffy-null status with HIV disease course differed according to WBC but not CD4(+) T-cell counts, such that leukopenic but not nonleukopenic HIV(+) AAs with DARC -46C/C had a survival advantage compared with all Duffy-positive subjects. This survival advantage became increasingly pronounced in those with progressively lower WBC counts. These data highlight that the interaction between DARC genotype and the cellular milieu defined by WBC counts may influence HIV disease course, and this may provide a partial explanation of why ethnic leukopenia remains benign in HIV-infected AAs, despite immunodeficiency.

Influences of thiopurine methyltransferase genotype and activity on thiopurine-induced leukopenia in Korean patients with inflammatory bowel disease: a retrospective cohort study.

BACKGROUND AND AIM: Myelotoxicity has been shown to be very common in Korean patients with inflammatory bowel disease (IBD) during azathioprine (AZA) or 6-mercaptopurine (6-MP) treatment. The purpose of this study was to investigate the relative risk of the thiopurine methyltransferase (TPMT) and inosine triphosphate pyrophosphatase (ITPA) genotypes and TPMT activity for the development of leukopenia in Korean IBD patients during AZA/6-MP treatment. METHODS: We retrospectively analyzed 286 Korean patients with IBD who had been treated with AZA/6-MP for at least 6 months between June 1996 and September 2006. Common TPMT mutations, including TPMT*1, *2, *3A, *3B, and *3C, and ITPA mutations, including 94C>A and IVS2+21A>C, were determined using a high-performance liquid chromatography method. TPMT activity was measured using liquid chromatography with coupled mass spectrometry/mass spectrometry. RESULTS: Leukopenia occurred in 118 cases (41.3%). TPMT *1/*3C was detected in 7 cases (2.4%), and ITPA 94 C>A was detected in 66 cases (23.1%), including 63 heterozygotes (22.1%) and 3 homozygotes (1.0%). The median TPMT activity was 9.3 U/mL (interquartile range 10.4, range 2.1 to 76.2). Cox regression analysis revealed that patients with heterozygous *3C type TPMT had a higher probability of leukopenia than those with wild type TPMT (P=0.02). Patients with intermediate TPMT activity had a lower probability of leukopenia than those with low activity (P=0.01). However, the ITPA genotype did not affect the risk of leukopenia. CONCLUSIONS: Our data showed that it could be helpful to examine TPMT genotypes and to measure TPMT activity in Korean patients taking AZA/6-MP to predict the development of leukopenia.

A phase II trial of epirubicin, oxaliplatin, and capecitabine (EOX) as first-line chemotherapy in advanced gastric cancer: a Chinese single-center experience.

OBJECTIVE: This study aimed at evaluating the efficacy and safety of epirubicin, oxaliplatin, and capecitabine (EOX) in advanced gastric cancer (AGC) patients in the Chinese population. PATIENTS AND METHODS: Patients with previously untreated advanced measurable gastric cancer received epirubicin (50 mg/m(2), day 1), oxaliplatin (130 mg/m(2) 2-hour infusion, day 1) and capecitabine (625 mg/m(2) orally, twice daily, days 1-21) every 3 weeks. RESULTS: Of 48 enrolled patients, 47 were evaluable for efficacy and 48 for toxicity. A median of five cycles (range 1-8) was administered. The overall response rate was 51.1% (95% CI 36-66) with two complete responses, 22 partial responses, 16 stable diseases, and 7 progressions. Median progression-free survival was 6.5 months (95% CI 5.6-7.4) and median overall survival was 10.4 months (95% CI 8.8-12.0). Grade 3-4 neutropenia and anemia were observed in 22.9 and 6.3% of patients, respectively. Grade 3-4 nonhematological toxicities included alopecia (18.9%), nausea (8.3%), vomiting (6.3%), diarrhea (6.3%), hand-foot syndrome (4.2%) and neurological toxicity (2.1%). CONCLUSION: In our experience, the EOX regimen was highly effective, well tolerated and conveniently delivered as first-line chemotherapy for AGC patients in the Chinese population.

Ethnic and genetic causes of neutropenia: clinical and therapeutic implications.

The white blood cell count represents clinical data linked with different pathologic conditions, as well as with lifestyle. Another very important condition that affects the number of leukocytes is race and ethnic group-the geographic zone of origin. Genetic studies have identified the gene that controls the expression of the Duffy antigen receptor for chemokine (DARC), which is associated with the ethnic group to which individuals belong. The single-nucleotide polymorphism strongly associated with race is DARC rs2814778. Currently, it is the only condition that can explain the difference in white blood cell count between different ethnic groups. In a society increasingly characterized by multiracial issues, the leukopenia and/or neutropenia in ethnic groups must be known and accurately assessed clinically. Improved knowledge of this association may help in optimizing therapeutic approaches, mainly for African patients with severe diseases, cancer in particular. Recently, preclinical data have also suggested a link between the Duffy antigen and coagulation. This review also discusses the main causes of genetic neutropenia.

Hematologic Manifestations of Brucellosis in Children.

BACKGROUND: Brucellosis is a common zoonosis in the Bedouin population of southern Israel. Limited data exist for the rate and risk factors of hematologic complication of brucellosis in children. We assessed anemia, leukopenia, thrombocytopenia and pancytopenia in childhood brucellosis in southern Israel. METHODS: Our medical center is the sole hospital in southern Israel. All medical files of brucellosis, 2005-2014, identified through positive blood cultures or International Classification of Diseases 9th revision coding with positive serology, were reviewed retrospectively. RESULTS: Overall, 511 brucellosis episodes were identified; 42% (N = 214) with ≥1 cytopenia, including 13% (N = 68) anemia, 28% (N = 144) leukopenia, 14% (N = 74) thrombocytopenia and 2% (N = 9) pancytopenia. Overall, 99.8% of episodes were in Bedouin children and 70% in males. In 79% of episodes, blood culture was positive for Brucella melitensis. Acute infections comprised 84% of all episodes. In univariate analysis, older age (10.49 ± 4.81 vs. 9.25 ± 4.89 years), fever (92% vs. 78%), positive blood culture (84% vs. 75%) and IgM ≥1:640 levels (50% vs. 39%) were associated with cytopenia. In contrast, arthralgia was associated with noncytopenic episodes. In multivariate analyses, older age (odds ratio = 1.063) and fever (odds ratio = 3.127) were associated with cytopenia. CONCLUSIONS: Brucellosis is commonly presented with cytopenia, especially in bacteremic episodes with fever. However, pancytopenia is uncommon and its finding should alert the physician to look for other possible etiologies.

Maximizing clozapine utilization while minimizing blood dyscrasias: evaluation of patient demographics and severity of events.

The aim of this study was to determine whether patient characteristics such as age, sex, race/ethnicity, and frequency of monitoring play a role in clozapine-related blood dyscrasias. This study examined all neutropenic events to identify any potential demographic qualities that may pose increased risk to individuals receiving clozapine treatment in accordance with the FDA guidelines released in 2005. These guidelines required the addition of absolute neutrophil count (ANC) tests in addition to white blood cell (WBC) counts to regular monitoring and a reduction in the frequency of testing to once monthly after 1 year of satisfactory WBC counts and ANCs. The previous schedule neither included ANC testing nor allowed for further reductions in the frequency of testing after 1 year, with patients continuing to be tested every 2 weeks indefinitely. This is a retrospective, closed chart review of all patients who received clozapine at the State Psychiatric Center and experienced a leukopenic/neutropenic event and/or who had a substantial drop in WBC/ANC from January 2009 to December 2011. A subset of patients who were identified as achieving 'non-rechallengeable' status with either an ANC and/or WBC threshold value from 2001 to 2014 were also examined. This protocol was approved by the New York State Psychiatric Institute Institutional Review Board. A total of 193 patients were included in the study. Males experienced more total events at 6.4 events per person compared with 5.2 events per woman. White patients had 6.5 total events per person compared with 4.2 total events per Black patient; however, Black patients experienced more moderate leukopenia/granulocytopenia events compared with Whites. Regardless of race or ethnicity, patients in the 40-49-year age range had the most events at 8.1 events per person and also presented with the highest number of moderate leukopenia/granulocytopenia events as did those scheduled for weekly monitoring. Conversely, the majority of patients with no recorded events were female and either 20-29 or 60-69 years of age. In total, 16 patients were exclusively designated as non-rechallengeable from 2001 to 2014 and only had one single blood event prompting this clozapine monitoring status. Of these 16 patient events, seven were White males, eight were White females, and one was a Black female with roughly 40% of those patients in the 50-59-year age group. Currently published predictions on possible demographic risk groups may not reflect clinical experience and may pose unnecessary treatment barriers in the provision of clozapine. Although the healthcare team should be aware of the possible demographic predictors of blood dyscrasias when using clozapine, treatment goals and monitoring strategies must be individualized to ensure successful clozapine therapy.

NUDT15 variant is the most common variant associated with thiopurine-induced early leukopenia and alopecia in Korean pediatric patients with Crohn's disease.

PURPOSE: Thiopurine-induced leukopenia is a relatively common adverse event related to thiopurine medication in Korean pediatric Crohn's disease. In addition to the mutations of TPMT gene, the NUDT15 c.415C>T variant was recently identified to have a strong association with thiopurine-induced early leukopenia. We conducted this study to define the incidence of azathioprine (AZA)-related leukopenia and to determine the incidence and characteristics of their genetic variants in Korean pediatric Crohn's disease patients. PATIENTS AND METHODS: Patients diagnosed with pediatric Crohn's disease who had used AZA for more than 3 months were recruited. The dose and duration of medication and data regarding adverse events including leukopenia were collected. TPMT and NUDT15 gene sequencing was performed for patients who had experienced AZA-induced leukopenia. RESULTS: A total of 81 patients had used AZA as a maintenance therapy of Crohn's disease. The mean dose of AZA was 1.88±0.39 mg/kg/day. Nine patients (11.1%) experienced AZA-induced leukopenia, and eight patients (9.9%) experienced AZA-induced early leukopenia. Among the eight early leukopenia patients, six patients (75.0%) harbored the NUDT15 c.415C>T variant and one patient (12.5%) had the TPMT c.719A>G (TPMT*3C) variant. All the three patients with NUDT15 c.415C>T homozygous variant suffered from alopecia totalis, and two of them experienced severe systemic infection. Three patients with the NUDT15 heterozygous variant are currently treated with AZA at a dose of 0.76 mg/kg/day. CONCLUSION: Mutations of the NUDT15 and TPMT gene accounted for ∼88% of cases with thiopurine-induced early leukopenia. Extensive hair loss was a recognizable early symptom in patients with the homozygous NUDT15 c.415C>T variant. Sequencing of the NUDT15 genes can guide the clinicians before thiopurine medication. An alternative immunosuppressive medication is recommended for patients with homozygous NUDT15 c.415C>T variant. For those with the heterozygous variant, half the usual dose of AZA can achieve efficacy comparable to that for wild-type patients.

Leukopenia, neutropenia, and reduced hemoglobin levels in healthy American blacks.

Hematologic profiles of 462 persons, mostly active-duty service members, were studied to determine whether hematologic differences between blacks and whites exist in a healthy population. Whites had significantly greater mean concentrations of leukocytes (6.73 vs 5.95 x 10(9)/L), neutrophils (3.96 vs 3.16 x 10(9)/L), and hemoglobin (153 vs 135 g/L for men, 147 vs 125 g/L for women). The mean differences were largely due to relatively symmetric shifts in the frequency distributions for these cell concentrations. No significant correlation was found between neutrophil count and morbidity from infection as measured by a standardized questionnaire. The use of separate hematologic reference values for blacks and whites should be considered.

Leukogram and white blood cells count in native people of Chukotka.

A representative sample of male and female Chukotka natives aged 25-6 years (362 persons) has been surveyed using the cross-sectional epidemiological method. The results have been compared with the data obtained when surveying a representative sample of the non-organised population of the same age in Novosibirsk (n = 2071 persons). The mean age was 43 years. The total count of white blood cells (WBC) in peripheral blood of Chukotka natives was lower than the corresponding values of that index in the inhabitants of Novosibirsk, the 10-90% range of white blood counts being 3.0-7.0 10(9)/l in natives and 4.0-9.0 10(9)/l in residents of Novosibirsk. A significant incidence of leukopenias (<4.0 10(9)/l) has been detected, being 30% in the population of Chukotka, 24% in men and 35% in women. Modification in White Blood Cells differentials (leukogram) has been found in native Chukotka people, particularly relative and absolute lymphocytopenia.

Benign familial leukopenia and neutropenia in different ethnic groups.

Benign hereditary leukopenia-neutropenia has been reported in several ethnic groups, including Yemenite Jews, Blacks of South African extraction, West Indians and Arab Jordanians. The subjects with BFL were shown not to have an increased incidence of infections, and their response to infection did not differ from subjects having normal white blood cell counts. This study entails the report of two additional unrelated ethnic groups with familial neutropenia - Black Beduin and Falashah Jews. The familial nature of the phenomenon was confirmed. The suggested mechanism of this type of neutropenia is a defect in release of mature WBC from the bone marrow to the peripheral circulation. All ethnic groups thus far reported have tanned or dark skin. The significance of this common feature has still to be elucidated.