Polymorphisms of interleukin-1 gene complex, IL6 and tumour necrosis factor genes in chronic idiopathic neutropenia of adults

Benign ethnic neutropenia: an analysis of prevalence, timing and identification accuracy in two large inner-city NHS hospitals

BACKGROUND

Benign ethnic neutropenia (BEN) is the most common cause of chronic neutropenia seen in individuals of African, Middle Eastern and West Indian descent. This phenotype is broadly defined by an absolute neutrophil counts (ANC) below 1.8 × 10⁹ cells/L in the absence of other causes, without an increased risk of infection. BEN has been implicated as a potential source of disparity in patients treated with clozapine, the antipsychotic of choice in treatment-resistant schizophrenia. Our main objective was to examine the current level of BEN recognition in a cohort of patients treated with clozapine and the potential impact of unidentified BEN on the initiation and maintenance of clozapine treatment.

METHODS

This was an observational, retrospective analysis of patients registered with clozapine haematological monitoring systems in two large mental health trusts, chosen because they serve an ethnically diverse population. The first objective was to establish certified BEN prevalence in current users of clozapine. The second objective was to explore the stage of treatment at which BEN was identified. The third objective was to evaluate the extent of unrecognised BEN in patients registered on the Central Non-Rechallenge Database (CNRD), a database for patients whose haematological parameters fall below set thresholds when receiving clozapine treatment, meaning they cannot ordinarily be prescribed clozapine again.

RESULTS

The study population comprised of 2020 patients on the clozapine register. 111 patients were monitored under BEN criteria. BEN was mostly identified after a below threshold haematological result or clozapine rechallenge (68%) compared to at clozapine initiation (32%). Eight of the 18 (42%) black patients registered on the CNRD were classified as BEN after assessment by a haematologist. Of these 8 patients, none would have met CNRD criteria again if monitored with BEN criteria at clozapine initiation.

CONCLUSIONS

Current evidence suggests that BEN remains an uncommonly recognised haematological phenotype. Improved timely identification of BEN will reduce unnecessary interruption or discontinuation of clozapine treatment. Our results suggest consideration should also be given to determining BEN status prior to initiating clozapine. Moreover, adoption of current FDA BEN monitoring criteria in the UK may further reduce clozapine discontinuation due to perceived neutropenia as drug toxicity, particularly in treatment-refractory schizophrenia patients.

Duffy phenotyping and FY*B-67T/C genotyping as screening test for benign constitutional neutropenia

OBJECTIVE

Low levels of neutrophils can be an intrinsic condition, with no clinical consequences or immunity impairment. This condition is the benign constitutional neutropenia (BCN), defined as an absolute neutrophils count (ANC) ≤2000 cells/mm. Diagnosis of BCN is of exclusion where patients are submitted to blood tests and possibly to invasive diagnostic search until secondary causes of neutropenia are ruled out. The natural history of the disease suggests benign evolution and Brazilian study showed an overall frequency of 2.59%. The main mechanisms include reduced neutrophil production, increased marginalization, extravasation to the tissues and immune destruction. Genetic studies showed strong association between the single nucleotide variant rs2814778 located on chromosome 1q23.2 in the promoter region of the atypical chemokine receptor 1 (Duffy blood group system) gene (ACKR1, also termed DARC) and BCN. The aim of this study is to evaluate FY phenotypes and genotypes including the analysis of the rs2814778 SNP in Brazilian patients with BCN in order to determine an effective diagnostic tool, allowing reassurance of the patient and cost reduction in their care.

METHODS

Case control study, with 94 individuals (18 patients and 76 controls). Phenotyping was performed by gel test and genotyping was performed by PCR-RFLP.

RESULTS

White blood cell (WBC) and absolute neutrophils (AN) counts showed lower levels in patients compared to controls. In the patient group 83.3% were genotyped as FY*B/FY*B. The SNP rs2814778 (-67T > C) was identified in 77.8% of the patients genotyped as FY*B-67C/FY*B-67C. In the control group, 72.7% were homozygous for the wild type and 23.3% were heterozygous.

CONCLUSION

This study reinforces that FY phenotyping and genotyping can be used to detect most people with BCN, avoiding excessive diagnostic investigation. Besides, this procedure may reduce health costs and be reproductible in clinical practice.

Associations of the TNF-alpha -308 G/A, IL6 -174 G/C and AdipoQ 45 T/G polymorphisms with inflammatory and metabolic responses to lifestyle intervention in Brazilians at high cardiometabolic risk

BACKGROUND

Cytokines secreted by the adipose tissue influence inflammation and insulin sensitivity, and lead to metabolic disturbances. How certain single-nucleotide polymorphisms (SNPs) interfere on lifestyle interventions is unclear. We assessed associations of selected SNPs with changes induced by a lifestyle intervention.

METHODS

This 9-month intervention on diet and physical activity included 180 Brazilians at high cardiometabolic risk, genotyped for the TNF-α -308 G/A, IL-6 -174 G/C and AdipoQ 45 T/G SNPs. Changes in metabolic and inflammatory variables were analyzed according to these SNPs. Individuals with at least one variant allele were grouped and compared with those with the reference genotype.

RESULTS

In the entire sample (66.7% women; mean age 56.5 ± 11.6 years), intervention resulted in lower energy intake, higher physical activity, and improvement in anthropometry, plasma glucose, HOMA-IR, lipid profile and inflammatory markers, except for IL-6 concentrations. After intervention, only variant allele carriers of the TNF-α -308 G/A decreased plasma glucose, after adjusting for age and gender (OR 2.96, p = 0.025). Regarding the IL6 -174 G/C SNP, carriers of the variant allele had a better response of lipid profile and adiponectin concentration, but only the reference genotype group decreased plasma glucose. In contrast to individuals with the reference genotype, carriers of variant allele of AdipoQ 45 T/G SNP did not change plasma glucose, apolipoprotein B, HDL-c and adiponectin concentrations in response to intervention.

CONCLUSION

The TNFα -308 G/A SNP may predispose a better response of glucose metabolism to lifestyle intervention. The IL-6 -174 G/C SNP may confer a beneficial effect on lipid but not on glucose metabolism. Our findings reinforce unfavorable effects of the AdipoQ 45 T/G SNP in lipid profile and glucose metabolism after intervention in Brazilians at cardiometabolic risk. Further studies are needed to direct lifestyle intervention to subsets of individuals at cardiometabolic risk.

Genetic associations in acquired immune-mediated bone marrow failure syndromes: insights in aplastic anemia and chronic idiopathic neutropenia

Increasing interest on the field of autoimmune diseases has unveiled a plethora of genetic factors that predispose to these diseases. However, in immune-mediated bone marrow failure syndromes, such as acquired aplastic anemia and chronic idiopathic neutropenia, in which the pathophysiology results from a myelosuppressive bone marrow microenvironment mainly due to the presence of activated T lymphocytes, leading to the accelerated apoptotic death of the hematopoietic stem and progenitor cells, such genetic associations have been very limited. Various alleles and haplotypes of human leucocyte antigen (HLA) molecules have been implicated in the predisposition of developing the above diseases, as well as polymorphisms of inhibitory cytokines such as interferon-γ, tumor necrosis factor-α, and transforming growth factor-β1 along with polymorphisms on molecules of the immune system including the T-bet transcription factor and signal transducers and activators of transcription. In some cases, specific polymorphisms have been implicated in the outcome of treatment on those patients.

C reactive protein as a predictor of neutrophil recovery in autoimmune neutropenia

Primary autoimmune neutropenia (AIN) is more common in newborns, and usually benign or self-limiting, so most cases require no specific therapy. In adults, however, for little tendency toward spontaneous remission, they require certain treatments and careful managements. Here we report a successful management of primary AIN patient by estimating the granulopoiesis according to CRP levels without administration of G-CSF or increase of prednisolone when peripheral neutrophil counts dropped down. Transient elevation of CRP associated with severe drop down in neutrophil count, and subsequent dramatic neutrophil increase was occasionally observed during the follow up with minimal dose of prednisolone. Coexistence of decreased neutrophil counts and elevated CRP levels was accompanied by increase of serum levels of IL-6 and IL-8. Although this is the report of only one patient, these elevated CRP levels combined with severe drop down and subsequently spontaneous rapid recovery in neutrophil count, were repetitively observed, suggesting the preceding CRP elevation before neutrophil recovery. We propose the important part of CRP as a predictor of granulopoiesis in patients with neutropenia.

Prevalence and risk factors of atrophic gastritis and intestinal metaplasia in a Korean population without significant gastroduodenal disease

BACKGROUND AND AIM

The prevalence of gastric cancer and Helicobacter pylori infection is unacceptably high in Korea. This study was performed to evaluate the prevalence of atrophic gastritis (AG) and intestinal metaplasia (IM) and to identify their risk factors with respect to H. pylori virulence factors, and environmental and host factors, in Korean population without significant gastroduodenal disease.

METHODS

The study cohort consisted of 389 subjects (> or = 16 years). AG and IM were scored histologically using the Sydney classification in the antrum and body, respectively. Prevalences and bacterial factors (i.e. cagA, vacA m1, and oipA), environmental factors (i.e. smoking and alcohol), and host factors (i.e. genetic polymorphisms of IL-1B-511, IL-1RN, TNF-A-308, IL-10-592, IL-10-819, IL-10-1082, IL-8-251, IL-6-572, GSTP1, p53 codon 72, and ALDH2) were evaluated.

RESULTS

Prevalences of AG in the antrum and body were 42.5% and 20.1%, and those of IM were 28.6% and 21.2%, respectively. The presences of AG and IM were significantly higher in H. pylori-positive than in the H. pylori-negative subjects. Multivariate analysis showed that the risk factors for AG were H. pylori infection, age > or = 61 years, and cagA and vacA m1 positivity. For IM the risk factors were H. pylori infection, age > or = 61 years, a smoking history (rather than current smoking), strong spicy food, occupation (unemployed or nonprofessional vs. professional), and the presence of IL10-592 C/A as opposed to A/A. In addition, IL6-572 G carrier was found to have a protective effect against IM development as compared with C/C.

CONCLUSION

H. pylori infection was most important risk factor of AG and IM. Bacterial factors were found to be important risk factor for AG but environmental and host factors were more important for IM.