The risk of malignancies in patients receiving hematopoietic stem cell transplantation: a systematic review and meta-analysis

INTRODUCTION

Hematopoietic stem cell transplantation (HSCT) is widely used in the treatment of malignant and non-malignant diseases. Due to advances in the number of survivors of this treatment, the number of survivors is increasing, but the late complications of this therapeutic approach such as secondary cancers have been long term and have not been fully controlled.

METHODS

The present meta-analysis study was performed by considering English-language articles in the databases including Web of Science, Scopus and PubMed. This meta-analysis included cohort studies that reported an incidence of cancer following stem cell transplantation (SCT). Random/fixed effect size meta-analyses were used to standardize the incidence ratio for different cancers.

RESULTS

22 studies that evaluated patients receiving SCT (n = 270,063) were included in the study. The study found 9233 cases of cancer after transplantation. Meta-analysis showed that the risk of cancer after SCT was SIR = 1.66 (95% CI 1.47-1.86). The most common cancers observed in SCT recipients were bone tissue, head and neck cancers, and melanoma, with SIRs of 10.04 (3.48-16.61), 6.35 (4.76-7.93) and 3.52 (2.65-4.39), respectively.

CONCLUSION

The meta-analysis findings showed that the risk of secondary cancers after HSCT was significantly increased in most types of cancers. Consequently, diagnostic tests for common cancers should be included in the screening program of these patients for the prevention and early detection of high-risk cancers.

Relationship between blood group and risk of infection and death in COVID-19: a live meta-analysis

The relationship between ABO blood group and the incidence of coronavirus disease 2019 (COVID-19) infection and death has been investigated in several studies. The reported results were controversial, so the objective of the present study was to assess the relationship between different blood groups and the onset and mortality of COVID-19 infection using a meta-analysis method. We searched relevant databases using appropriate MeSH terms. We screened articles on the bases of titles, abstracts and full text, and articles that met the inclusion criteria were selected. Quality assessment was done with the Newcastle-Ottawa scale checklist. The estimated frequency of COVID-19 infection and death in terms of ABO blood group and the overall estimate of the odds ratio between blood group with COVID-19 infection and death was calculated with 95% confidence interval. The pooled frequency of blood groups A, B, O and AB among COVID-19-infected individuals was estimated as 36.22%, 24.99%, 29.67% and 9.29% respectively. The frequency of blood groups A, B, O and AB among patients who died of COVID-19 infection was estimated as 40%, 23%, 29% and 8% respectively. The odds ratio of COVID-19 infection for blood group A versus the other blood groups was estimated as 1.16 (95% confidence interval (CI), 1.02-1.33). The corresponding figures for blood groups O and AB versus other blood groups were estimated as 0.73 (95% CI, 0.60-0.88) and 1.25 (95% CI, 0.84-1.86) respectively. This meta-analysis showed that individuals with blood group A are at higher risk for COVID-19 infection while those with blood group O are at lower risk. Although the odds ratio of death for AB blood group was nonsignificant, it was considerable.

Systematic review with meta-analysis: the worldwide prevalence of Helicobacter pylori infection

BACKGROUND

The epidemiology of Helicobacter pylori infection is poorly understood.

AIM

To establish the reported regional and national prevalence of H. pylori infection, stratified by age and gender.

METHODS

All relevant English publications from 2000 to 2017 cited by PubMed and Scopus were retrieved using comprehensive combinations of keywords. The overall prevalence of H. pylori was estimated using both random effect and fixed effect meta-analyses, and presented as prevalence rate (% and 95% CI). The analyses were extended by separation into gender and age groups.

RESULTS

A total of 14 056 records were obtained initially. After applying exclusion criteria in several steps, 183 studies were selected. Analysis of 410 879 participants from 73 countries in six continents revealed an overall prevalence of 44.3% (95% CI: 40.9-47.7) worldwide. This rate ranged from 50.8% (95% CI: 46.8-54.7) in developing countries compared with 34.7% (95% CI: 30.2-39.3) in developed countries. The global H. pylori infection rate was 42.7% (95% CI: 39-46.5) in females compared to 46.3% (95% CI: 42.1-50.5) in males. The prevalence in adults (≥18 years) was significantly higher than in children (48.6% [95% CI: 43.8-53.5] vs 32.6% [95% CI: 28.4-36.8], respectively). There was a statistically nonsignificant decrease in the prevalence in 2009-2016 compared with the 2000-2009 period.

CONCLUSIONS

The observed differences between countries appear to be due to economic and social conditions. H. pylori infection can be a benchmark for the socioeconomic and health status of a country. Further studies are suggested to investigate the natural history of the acquisition of H. pylori infection from childhood into adult life.

Gene susceptibility in Iranian asthmatic patients: a narrative review

As environmental factors are important in the development of asthma, genetic factors could have a critical role in the expression of the disease. Hence, we carried out a systematic review to assess the susceptible genes for asthma in Iranian population. We conducted a literature search by using the electronic database PubMed, Biological Abstracts Web of Science, Current Contents Connect, Cinahl, ScienceDirect, Scopus, IranMedex, and Scientific Information Database to identify articles that evaluated the association between genetic variants and the risk of asthma in Iranian population (until April 30, 2012). The search terms were used include: Asthma and gene in combination with Iran for international database. The following criteria were used for selecting literatures in this review: The study should evaluate the association between gene polymorphism and risk of asthma in Iranian population, and the study should be a case-control design with normal subject as ac control group that published in a journal. Finally, 14 case-control studies were extracted from local and international database. In this study, we reviewed 38 polymorphisms in 19 genes. Polymorphism in interleukin-13 (IL-13), IL-10, IL-1, IL-2, IL-12, E-Selectin, S128R and Exon 9 Vitamin D Receptor were susceptible for asthma and polymorphism in chemokine receptor 5, transforming growth factor-a (TGF-a), Intron 8 of the Vitamin D Receptor, angiotensin-converting enzyme gene, IL-6 and interferon-c were not susceptible for asthma in Iranian population. Polymorphism in IL-4, tumor necrosis factor-α and TGF-b had inconsistent findings. This systematic review indicated that three polymorphisms (IL-13, IL-10, and IL-1) are associated with risk of asthma in Iranian population.

Incidence of leptospirosis in Mazandaran Province, north of Iran: a one year survey

The aim of this study was to provide the first report of incidence of leptospirosis and to determine the epidemiology of this zoonotic disease in Mazandaran Province, North of Iran. In the period of one year, from April 2007 to April 2008, forty seven confirmed reports of human cases of leptospirosis was received by Mazandaran Health Centre from local hospitals and leptospirosis laboratory. The annual incidence rate for the total population was 1.6 per 100,000 person-year. The majority of cases were males (84.1%). The maximum number of cases was seen to occur between 40 and 59 years of age. Seasonal outbreak of leptospirosis was seen in summer (70.3%). Farmers (57.4%) more frequently affected by disease than other occupations. In conclusion, it is necessary for medical practitioner to pay attention to leptospirosis in farmers during summer season.