Helicobacter pylori infection and risk of multiple sclerosis: An updated meta-analysis

BACKGROUND

There is considerable controversy around the question as to whether Helicobacter pylori (H. pylori) infection has a protective or causative role in the development of multiple sclerosis (MS). This study evaluated published information to assess the association between H. pylori infection and MS.

METHODS

We conducted a comprehensive systematic review of relevant observational studies in international databases. A random-effects model was used to calculate pooled odds ratio (OR) and 95% confidence interval (CI). I² statistic was used to assess the between-study heterogeneity. Subgroup and meta-regression analyses were applied to identify the source of heterogeneity.

RESULTS

In total, 22 studies (25 datasets) were eligible for the meta-analysis: 17 datasets had prevalence data and eight datasets had data on the mean titer of anti-H. pylori IgG. The pooled prevalence of H. pylori was 44.1% (908/2606) in the MS patients and 46.1% (1016/2200) in the controls, indicating a non-significant protective effect of H. pylori on MS (OR, 0.82; 95%CI, 0.58-1.17). In the subgroup analysis, studies that used ELISA yielded a significant protective association (OR, 0.59; 95%CI, 0.46-0.77), while a positive non-significant association (OR, 1.33; 95%CI, 0.83-2.15) was found from studies that used other serological methods; interestingly, a significant positive association (OR, 6.64; 95%CI, 2.40-13.76) was found from studies that used histological methods to detect H. pylori infection.

CONCLUSIONS

Our findings do not support the hypothesis that H. pylori infection represents a protective factor against the development of MS; however, the results varied depending on the diagnostic method(s). Particularly, a significant positive association was identified when studies introduced results based on histological examination, suggesting that active H. pylori infection might be a risk factor for development of MS. Thus, further studies are needed utilizing accurate diagnostic methods to elucidate the association between active H. pylori infection and MS.

Does latent Toxoplasma infection have a protective effect against developing multiple sclerosis? Evidence from an updated meta-analysis

Previous epidemiologic evidence suggests a protective effect of Toxoplasma gondii infection against multiple sclerosis (MS) development; however, inconsistent findings have been reported in this regard. Therefore, we performed an updated meta-analysis of observational studies to investigate the association of To. gondii infection with MS development. We searched all articles published in PubMed, Scopus, Embase and Web of Science databases as of 20 December 2021. A random effects meta-analysis model was used to generate the pooled OR at 95% CIs. The heterogeneity between studies was assessed using I2 and Cochran's Q statistics. Moreover, the likelihood of publication bias was determined by Egger's regression test. A total of 11 studies were eligible for meta-analysis, including 1172 MS cases and 1802 controls. Our findings indicated that 29.8% (95% CI 22.8 to 37.2%) of MS patients were seropositive for To. gondii infection, compared with 34.2% (95% CI 21.9 to 47.6%) of control subjects. The estimated pooled OR was 0.79 (95% CI 0.49 to 1.26), suggesting a non-significant negative association between To. gondii infection and MS development (p>0.05). The current study does not support the significant protective role of To. gondii infection on MS development. Our findings imply that further well-designed epidemiological and mechanistic studies are warranted to ascertain the possible association between To. gondii infection and MS and to exclude the potential confounders.

The role of tranexamic acid in prevention of hemorrhage in major spinal surgeries

Background:

Blood loss that necessitates blood transfusion is one of the most frequent complications of major spinal surgeries. This study has been designed to evaluate the efficacy and safety of prophylactic tranexamic acid (TA) in decreasing perioperative blood loss.

Materials and Methods:

From January to August 2011, all the patients who needed major spinal surgeries and aged between 18 and 60-year-old were divided into two groups randomly, the experimental group received 10 mg/kg of TA 20 min after inducing the anesthesia as loading dose followed by 0.5 mg/kg/h until skin closure and the control group received equal amounts of normal saline as placebo. Intraoperative blood loss was recorded by estimating blood with the suction tube plus the number of bloody gasses. The amounts compared between the 2 groups and analyzed.

Results:

Forty patients were enrolled in this study in the first group intraoperative, the 1^st and 2^nd postoperative days, the mean blood loss were 574 ml, 80.5 ml, and 669.5 ml while in the second group were 797 ml, 124 ml, and 921.5 ml.

Conclusion:

TA seems to be safe and can be considered in spinal surgeries with significant excepted blood loss especially in female patients and instrumental procedures. We suggest further studies on TAs efficacy and safety in larger scales.