Helicobacter pylori infection and infertility

Helicobacter pylori and unignorable extragastric diseases: Mechanism and implications

Considered as the most popular pathogen worldwide, Helicobacter pylori is intensively associated with diverse gastric diseases, including gastric ulcers, chronic progressive gastritis, and gastric cancer. Aside from its pathogenic effect on gastric diseases, growing evidences reveal that H. pylori may be related to numerous extragastric diseases. In this article, we reviewed recent studies and systematically elucidated that H. pylori may interfere with many biological processes outside the stomach and influence the occurrence of various extragastric diseases. Many epidemiological studies have indicated that H. pylori plays a pathogenic role in COVID-19, atherosclerosis, hyperemesis gravidarum and several other extragastric diseases, while the effect of H. pylori is currently under investigation in gastroesophageal reflux disease, asthma, and inflammatory bowel disease. Moreover, we also summarized the possible pathogenic mechanisms of H. pylori that may be related to chronic systemic inflammation and molecular mimicker. Taken together, this review provides a new perspective on the role of H. pylori in extragastric diseases and explores the possible mechanisms, which may help guide clinical treatment.

Sperm parameters and anti-Müllerian hormone remain stable with Helicobacter pylori infection: a cross-sectional study

BACKGROUND AND AIMS

It has been reported that Helicobacter pylori (HP) infection was more prevalent in infertile populations. HP infection could lead to decreased sperm parameters, and treating the HP infection could improve the quality of sperm. However, studies investigating the relationship between infertility and HP infection are still limited, and more evidence is required. Therefore, we performed the present study to investigate the impact of HP infection on sperm quality in males and on ovarian reserve in females.

METHODS

A total of 16,522 patients who visited the Second Hospital of Zhejiang University from January 2016 to June 2019 due to abdominal discomfort and underwent a 13/14C-urea breath HP test were included in this retrospective cross-sectional study. Among them, 565 had performed sperm analysis or ovarian reserve tests in the past three months and were involved for further analyses. Sperm parameters were examined with a computer-assisted sperm analysis system, and serum anti-Müllerian hormone (AMH) and sex hormones were tested with an electrochemiluminescence method.

RESULTS

Among 363 patients who underwent the sperm test, 136 (37.47%) had HP infection. Among 202 patients who underwent the AMH test, 55 (27.23%) had HP infection. There was no difference in sperm concentration and motility between the HP+ and HP- groups (P > 0.05). Further subgroup analyses stratified into 5-year age groups confirmed that there was no significant difference in sperm parameters (P > 0.05). When pooled with previously published data, no significant difference in sperm concentration or motility was found (P > 0.05). Meanwhile, this study found that the serum AMH level was similar between the HP+ and HP- groups (P > 0.05). Further subgroup analyses confirmed that there was no significant difference in serum AMH level (P > 0.05).

CONCLUSIONS

There were no differences in sperm parameters and AMH levels based on history of HP infection among Chinese patients.

Bacterial infection of the male reproductive system causing infertility

Bacterial infections play a disruptive and hidden role in male reproductive failure. Different kinds of bacteria are often able to interfere with reproductive function in both sexes and lead to infertility. In this study, to further evaluate the role of bacterial infections in male reproduction we provided an extensive overview of so far researches investigating the effects of bacterial infections on male fertility. We searched Medline, PubMed, Scopus and Google scholar databases to identify the potentially relevant studies on bacterial infections and their implications in male infertility. All the bacteria included in this article have negative effects on the male reproductive function; however, there is ample evidence to blame bacteria such as Escherichia coli, Chlamydia trachomatis, Ureaplasma, Mycoplasma and Staphylococcus aureus for reduced fertility and deterioration of sperm parameters. More studies are needed to clarify the molecular mechanisms by which different bacteria exert their detrimental effects on male reproductive system. Getting more insight into probable mechanisms, would significantly facilitate the production of new, advanced, and effective remedies in the future. In view of all evidence, we strongly suggest increasing awareness among people and considering screening programs for patients seeking fertility both to avoid transmission and to improve fertility outcomes among them.

Effects of bacteria on male fertility: Spermatogenesis and sperm function

Bacterial infection can negatively affect different parts of the male genital tract and subsequently cause impaired spermatogenesis and male fertility. However, most of the previous studies have focused on the infected organs of the male genital tract and there are not many studies that investigated the direct effect of bacteria on sperm and their mechanism of action. Interestingly, bacteria can induce different damages on sperm cells such as DNA fragmentation, cell membrane peroxidation, and acrosome impairment. Such negative effects can be mediated by bacteria-secreted toxins and metabolites or by direct attachment of bacteria on the sperm cells and subsequent activation of signaling pathways related to oxidative stress, apoptosis, and inflammation. These bacteria-induced changes can impair semen parameters and subsequently cause infertility. Given the significant destructive effect of some bacteria on sperm function and male fertility, in this study, we reviewed the impact of male urogenital bacteria on spermatogenesis and sperm functions as well as the underlying mechanisms by which the bacteria can damage sperm.

Amelioration of sperm immobilisation factor-induced infertility by bacterial antigenic determinants cross-reacting with spermatozoa

A strain of Staphylococcus aureus, capable of invitro immobilisation of human and mouse spermatozoa, was already present in our laboratory. Therefore, in the present study, the factor responsible (sperm immobilisation factor, SIF) was isolated and purified. It was found to compromise not only motility, but also viability, morphology and Mg2+-ATPase activity of mouse spermatozoa. Also, SIF (250μgmL−1), when administered intravaginally in female BALB/c mice before mating, showed 100% contraceptive effect. Moreover, fluorescein isothiocyanate-labelled SIF was also found to bind mouse spermatozoa and various motile as well as non-motile bacteria, indicating the presence of common SIF-binding receptors on spermatozoa and bacteria. Further, to demonstrate molecular mimicry, the amelioration of SIF-induced impairment of sperm function by a SIF-binding bacterial receptor was compelling. For this, the SIF-binding receptor from Escherichia coli (E-SBR) was purified and evaluated for its ameliorative effect on SIF-induced sperm impairment invitro and invivo. Interestingly, upon the addition of mouse spermatozoa to SIF pre-incubated with E-SBR, an ameliorative effect against SIF-induced impairment of sperm function could be observed through analysis of normal sperm parameters (motility, viability, morphology, Mg2+-dependent ATPase levels). E-SBR also blocked binding of labelled SIF to spermatozoa and bacteria and alleviated SIF-induced infertility in female BALB/c mice. This provided evidence for molecular similarities between bacteria and spermatozoa, owing to which anti-bacterial antibodies cross-reacting with spermatozoa might be produced and infertility might follow.

Receptor from Streptococcus pyogenes as a potential antidote against sperm immobilization factor-induced sperm impairment and infertility

The present study was undertaken to demonstrate the existence of mimicry between spermatozoa and bacteria. For this, the shared antigenic determinants between mouse spermatozoa and Streptococcus pyogenes against a common ligand, sperm immobilization factor (SIF), were isolated. The mimicry was established on the basis of their ability to ameliorate the SIF-mediated compromised sperm parameters in vitro viz. motility, viability, morphology and Mg²⁺-ATPase activity of spermatozoa. Further, both the receptors i.e. SIF-binding receptor from mouse spermatozoa (MS-SBR) and SIF-binding receptor from S. pyogenes (S-SBR) were able to block the binding of FITC-labelled SIF to spermatozoa and bacteria. The in vivo studies also showed that MS-SBR (10 μg)/S-SBR (25 μg) could alleviate SIF-induced infertility in female BALB/c mice, further providing evidence for molecular similarities between bacteria and spermatozoa.

Molecular mimicry: An explanation for autoimmune diseases and infertility

Microorganisms execute an enthralling range of adjustments to survive in the host. Among the various strategies employed by microorganisms to surmount the host immune response, the phenomenon of molecular mimicry empowers the microorganisms to manoeuvre host physiology and cellular functions for their own advantage by mimicking the host proteins and initiating autoimmunity. This phenomena, by and large, has been studied in context of autoimmune diseases; however, its implications have also been reported in infertility. Hence, in this article, we provide a review of the various instances of molecular mimicry initiated by bacteria, parasites and viruses in the world of autoimmune diseases and infertility.

A meta-analysis of the association between Helicobacter pylori (H. pylori) infection and hyperemesis gravidarum

BACKGROUND

Hyperemesis gravidarum remains a common, distressing, and significant yet poorly understood disorder during pregnancy. The association between maternal Helicobacter pylori (H. pylori) infection and hyperemesis gravidarum has been increasingly recognized and investigated. This study thus aimed to provide an updated review and meta-analysis of the topic.

METHODS

Using the search terms (H. pyloriOR Helicobacter ORHelicobacter pyloriOR infection) AND (pregnancy OR emesis OR hyperemesis gravidarum OR nausea OR vomiting), a preliminary search on the PubMed, Ovid, Web of Science, Google Scholar, and WanFang database yielded 372 papers published in English between January 1st, 1960 and June 1st, 2017.

RESULTS

A total of 38 cross-sectional and case-control studies, with a total of 10 289 patients were eligible for review. Meta-analysis revealed a significant association between H. pylori infection and hyperemesis gravidarum during pregnancy, with a pooled odds ratio of 1.348 (95% CI: 1.156-1.539, P < .001). Subgroup analysis found that serologic and stool antigen tests were comparable methods of detecting H. pylori as they yielded similar odds ratios.

LIMITATIONS

Although the studies did not have high heterogeneity (I²  = 28%), publication bias was observed, and interstudy discrepancies in the diagnostic criteria adopted for hyperemesis gravidarum limit the reliability of findings. Also, 15 of the included studies were from the same country (Turkey), which could limit the generalizability of current findings. The prevalence of H. pylori infection varies throughout the world, and there may also be pathogenic differences as most strains of H. pylori in East Asia carry the cytotoxin-associated gene A gene.

CONCLUSION

H. pylori infection was associated with an increased likelihood of hyperemesis gravidarum during pregnancy. Given the high prevalence of H. pylori infections worldwide, detecting H. pylori infection and the eradication of maternal H. pylori infection could be part of maternal hyperemesis gravidarum management. Further confirmation with robust longitudinal studies and mechanistic investigations are needed.

Infectious Burden and Semen Parameters

OBJECTIVE

To investigate the relationship between chronic infections detected in serum and semen quality. The pathogen burden is a concept consisting in the observation that, in patients with heart disease, damaging effects of the coronary arteries increase concomitantly with the number of agents responsible for chronic infections to which patients mounted a serological response. Previous observations that Helicobacter pylori infection may reduce the semen quality prompted us to perform the present study.

METHODS

Blood and semen samples were collected from 73 selected men, enrolled from January 2014 to January 2015. Semen characteristics were evaluated by light and transmission electron microscopy. Transmission electron microscopy data were quantified with a mathematical formula providing numerical scores, such as fertility index (FI, number of sperm free from ultrastructural defects) and the percentages of sperm apoptosis, immaturity, and necrosis. Serum samples were examined by enzyme-linked immunosorbent assay for the presence of immunoglobulin G to the most common agents of chronic infections such as H. pylori (HP), Mycoplasma pneumoniae (MP), Chlamydophila pneumoniae (CP), Epstein-Barr virus (EBV), herpes simplex virus 1 (HSV-1), and cytomegalovirus (CMV).

RESULTS

The prevalence of infections was as follows: HP 43.8%, CP 46.6%, MP 72.6%, EBV 95.9%, HSV-1 74.0%, and CMV 46.6%. Concomitantly with the increased number of pathogens against which the patients mounted a significant antibody response, sperm concentration (P <.05), sperm motility (P <.001), and fertility index (P <.001) were significantly reduced and the percentage of necrotic sperm was increased (P <.01).

CONCLUSION

The higher the number of pathogens stimulating an immunoglobulin G systemic response, the lower was the semen quality.

Helicobacter pylori infection and polycystic ovary syndrome in adolescent and young adult patients

AIM

Polycystic ovary syndrome (PCOS) is the most common cause of infertility among women of reproductive age. Chronic systemic inflammation has been considered to play a role in the development of PCOS. Helicobacter pylori has been shown to lead to both local gastric and chronic systemic inflammation. In the light of this, the aim of the present study was to investigate a possible link between H. pylori and PCOS.

METHODS

A total of 167 nullipar and single adolescent and young adults (AYA) were recruited for the study: 86 (51.5%) had PCOS and 81 (48.5%) were age-matched controls. The average age was 18.57 ± 2.40 (range, 14-24 years). The recent Amsterdam European Society of Human Reproduction and Embryology/American Society for Reproductive Medicine (ESHRE/ASRM) guidelines including all three of the Rotterdam criteria were used to diagnose PCOS, and enzyme-linked immunosorbent assay kit was used to measure H. pylori IgG.

RESULTS

There was no significant association between the PCOS and non-PCOS groups with regard to the presence of H. pylori IgG (P = 0.924), white blood count or C-reactive protein (P = 0.064; P = 0.383, respectively).

CONCLUSION

The prevalence of H. pylori was not different with regard to PCOS status in AYA. More studies are needed to investigate a possible link between PCOS and H. pylori.

Seminal Helicobacter pylori treatment improves sperm motility in infertile asthenozoospermic men

OBJECTIVE

To assess the effect of treatment of seminal Helicobacter pylori in infertile asthenozoospermic men.

METHODS

In all, 223 infertile asthenozoospermic men were consecutively selected. They were subjected to history taking, clinical examination, semen analysis, and estimation of H pylori IgA antibodies in their seminal fluid. Infertile men with high seminal H pylori IgA were subjected to triple drug treatment, omeprazole, 20 mg; tinidazole, 500 mg; and clarithromycin, 250 mg twice a day for 2 weeks. Semen analysis as well as H pylori IgA antibodies was estimated after 3 months.

RESULTS

In all, 22 of 223 men (9.87%) demonstrated H pylori IgA antibodies in their seminal plasma. After treatment, mean seminal H pylori IgA levels demonstrated significant decrease (1.55 ± 0.4 vs 0.52 ± 0.26; 95% confidence interval, 0.83-1.21; P = .001) concomitant with improved progressive as well as nonprogressive sperm motility. H pylori IgA antibodies demonstrated significant negative correlation with progressive sperm motility, nonprogressive sperm motility, normal sperm morphology, and significant positive correlation with immotile sperm motility.

CONCLUSION

H pylori treatment significantly improves sperm motility in infertile asthenozoospermic men with elevated seminal H pylori IgA.

Hepatitis B virus infection reduces fertilization ability during in vitro fertilization and embryo transfer

Whether hepatitis B virus (HBV) infection impairs human infertility is unclear. The present retrospective case-controlled study investigated the impact of HBV on sperm parameters, ovarian stimulation, and outcomes of in vitro fertilization (IVF) and embryo transfer. A total of 224 couples with at least one partner being HBsAg-seropositive undergoing their first IVF and embryo transfer cycle were identified, which included 77 couples with female partners being HBsAg-seropositive, 136 couples with male partners being HBsAg-seropositive, and 11 couples with both partners being HBsAg-seropositive. A total of 448 both HBsAg-seronegative couples served as controls. The percentage of normal sperm morphology was significantly lower in HBsAg-seropositive male partners than that in HBsAg-seronegative male partners (11.9 ± 9.4% vs. 19.0 ± 11.9%, P < 0.01). The duration of infertility was significantly prolonged in HBV-seropositive patients compared with HBV-seronegative patients (4.9 vs. 4.1 years, P < 0.01). Couples with female partners being HBsAg-seropositive had significantly lower top-quality embryo rate than control group (22.4% vs. 31.6%, P < 0.01). In addition, the fertilization rates in groups with male or female partners being HBsAg-seropositive were both significantly lower than the matched controls (80.2% vs. 82.8%, P < 0.05; 76.6% vs. 84.3%, P < 0.01, respectively). HBV infection was also found to be associated negatively with fertilization rate by logistic regression analysis (odds ratios: 0.410, 95% confidence interval: 0.186-0.906, P < 0.05). However, there was no significant difference in clinical pregnancy rates between HBsAg-seropositive and HBsAg-seronegative group. These results suggest that chronic HBV infection is likely to represent a significant cause of infertility.

CagA-positive Helicobacter pylori infection and reduced sperm motility, vitality, and normal morphology

Helicobacter pylori (HP) infection, particularly when caused by strains expressing CagA, may be considered a concomitant cause of male and female reduced fertility. This study explored, in 87 HP-infected males, the relationship between infection by CagA-positive HP strains and sperm parameters. HP infection and CagA status were determined by ELISA and Western blotting; semen analysis was performed following WHO guidelines. The amino acid sequence of human enzymes involved in glycolysis and oxidative metabolism were “blasted” with peptides expressed by HP J99. Thirty-seven patients (42.5%) were seropositive for CagA. Sperm motility (18% versus 32%; P < 0.01), sperm vitality (35% versus 48%; P < 0.01) and the percentage of sperm with normal forms (18% versus 22%; P < 0.05) in the CagA-positive group were significantly reduced versus those in the CagA-negative group. All the considered enzymes showed partial linear homology with HP peptides, but four enzymes aligned with four different segments of the same cag island protein. We hypothesize a relationship between infection by strains expressing CagA and decreased sperm quality. Potentially increased systemic levels of inflammatory cytokines that occur in infection by CagA-positive strains and autoimmune phenomena that involve molecular mimicry could explain the pathogenetic mechanism of alterations observed.

[Helicobacter pylori - 2012]

The author overviews some aspects of literature data of the past 2 years. Genetic research has identified polymorphisms of Helicobacter pylori virulence factors and the host which could play a role in the clinical outcome of the infection (peptic ulcer or gastric cancer). So far they have been performed in research centers but with a decrease of costs, they will take their place in diagnosing the diseases and tailoring the treatment. Antibiotic resistance is still growing in Southern European countries and is decreasing in Belgium and Scandinavia. Currently, the clarithromycin resistance rate is of 17-33% in Budapest and levofloxacin resistance achieved 27%. With careful assessment of former antibiotic use the resistance to certain antibiotics can be avoided and the rates of eradication improved. Immigration is a growing problem worldwide: according to Australian, Canadian and Texan studies, the prevalence of Helicobacter pylori is much higher in the immigrant groups than in the local population. An Italian study showed that the eradication rate of triple therapy is significantly lower in the Eastern European immigrants than in the Italians. A recent research has suggested a link between female/male infertility, habitual abortion and Helicobacter pylori infection. However, there are no published data or personal experience to show whether successful eradication of the virus in these cases is followed by successful pregnancies or not. The author overviews the Maastricht process and analyzes the provisions of the Maastricht IV/Florence consensus, in which the new diagnostic algorithms and indications of eradication therapy are reformulated according to the latest levels of evidence and recommendation grading. According to the "test and treat" strategy, either the urea breath test or the stool monoclonal antigen test are recommended as a non-invasive diagnostic method in primary care. Endoscopy is still recommended in case of alarm symptoms, complicated ulcer, or if there is a suspicion of malignancy or MALT lymphoma. Local resistance to clarithromycin and levofloxacin should be considered in the choice of first-line therapy, in case of levels >15-20% these compounds should not be used. In regions with low resistance rates, classical triple therapy remains the regimen of choice; its alternative is the bismuth-based quadruple therapy. Determining antimicrobial resistance is justified after failed second- or third-line therapies; where available, molecular methods (fluorescence in situ hybridization, polymerase chain reaction) should be used. As second/third line treatments, the sequential, bismuth-based quadruple, concomitant quadruple regimens, hybrid are all possible alternatives. The Hungarian diagnostic and therapeutic approach in practice is different in some aspects from the provisions of the European consensus. Orv. Hetil., 2012, 153, 1407-1418.

Effect of Helicobacter pylori infection on pregnancy rates and early pregnancy loss after intracytoplasmic sperm injection

BACKGROUND

There is a need to elucidate what affects the implantation and early pregnancy course in pregnancies conceived with assisted reproductive technology (ART) so that pregnancy rates and outcomes can be improved. Our aim was to determine the role of maternal Helicobacter pylori infection.

MATERIAL AND METHODS

We did a prospective study of 187 infertile couples undergoing intracytoplasmic sperm injection (ICSI) and segregated those according to underlying infertility etiology. We assessed the status of H. pylori IgG antibodies and anti-CagA IgG antibodies by ELISA assay. All pregnancies were followed for early pregnancy loss (EPL, first 12 weeks).

RESULTS

The likelihood of H. pylori infection increased with age (1.01, 95% confidence interval [CI]: 1.0-1.13; P = 0.040) but there was no association with EPL. Women infected with CagA-positive strains were more likely to have EPL (19.39, 95% CI: 1.8-208.4; P = 0.014). Women with tubal factor or ovulatory disorder infertility were more likely to abort early (12.95, 95% CI: 1.28-131.11; P = 0.030, 10.84, 95% CI: 1.47-80.03; P = 0.020, respectively). There was no association between EPL and age, number of embryos formed or transferred, or number of oocytes retrieved.

CONCLUSION

Our findings suggest that infection with CagA-positive H. pylori strains is linked to an increase in women's potential to abort early (possibly through increased release of inflammatory cytokines). In addition, tubal factor and ovulatory disorder infertility are linked to EPL after ICSI due to unknown mechanisms. Proposals to eradicate H. pylori infection prior to ICSI could lead to a decrease in EPL after ART.

Adverse effects of hepatitis B virus on sperm motility and fertilization ability during IVF

The consequences of hepatitis B virus (HBV) infection for fertility are still unclear. Spermatozoa with decreased motility have been reported in HBV-infected patients. It has been demonstrated in vitro that HBV S protein has adverse effects on human sperm function with consequences for fertilization. In a case-control study design, 32 IVF cycles in couples with male HBV infection were compared with 64 cycles in non-infected couples, matched for age, time period, cycle rank and sperm parameters on the day of oocyte retrieval. Sperm motility before selection was significantly reduced in the HBV group (36.3 ± 11.6% versus 45.3 ± 14.4%,P = 0.003). A low fertilization rate (LFR) was more frequently observed in the HBV group (34.4% versus 15.6%, P = 0.036) and was associated with a decreased number of embryos available for transfer, although embryo quality on day 2 or 3 was not different.Implantation and pregnancy rates were comparable between groups. This study shows that HBV has a deleterious effect on sperm motility in vivo and that couples whose male partner is infected have a higher risk of LFR after IVF, a risk which is independent from the initial sperm motility.

Anti-Helicobacter pylori antibodies in cervical mucus: a new cause of infertility

OBJECTIVE

The aims of our study were to determine on the one hand a correlation between the presence of anti-Helicobacter pylori (anti-H. pylori) IgG antibodies in serum and cervical mucus of women with idiopathic infertility, and on the other hand the effect of these antibodies on cervical mucus quality, in particular related to the ability of spermatozoa to penetrate it.

STUDY DESIGN

We analysed anti-H. pylori IgG antibodies in the serum and cervical mucus of 67 patients diagnosed with idiopathic infertility using the Quanta Lite H. pylori IgG test. The penetration of normal sperm, in 15 cervical mucus samples positive for anti-H. pylori antibodies and in 15 negative samples, was assessed using the simplified slide test.

RESULTS

A significant positive correlation emerged between anti-H. pylori IgG antibody concentrations in the serum and in the cervical mucus (r=0.9275; p<0.00001). In the 15 anti-H. pylori IgG mucus-positive samples the slide test showed abnormal penetration by the spermatozoa.

CONCLUSIONS

Our study demonstrated that the presence of anti-H. pylori antibody in the cervical mucus can be involved in female infertility, interfering with sperm progression. Considering the close correlation found between serum and cervical mucus anti-H. pylori antibody titres, measuring serum antibodies could become an additional test, in particular in couples with unexplained infertility.

Infection by CagA-positive Helicobacter pylori strains may contribute to alter the sperm quality of men with fertility disorders and increase the systemic levels of TNF-alpha

This study was aimed to address the possibility that Helicobacter pylori infection may play a detrimental role in semen quality of men with idiopathic infertility. Infection by H. pylori and by strains expressing CagA was determined in 80 male infertile patients by Western blotting and ELISA. Semen analysis was performed by light microscopy and transmission electron microscopy quantitatively elaborated (fertility index, immaturity, necrosis, and apoptosis percentages). Systemic levels of IL-6 and TNF-alpha were evaluated. Infertile patients infected with H. pylori showed a low sperm quality respective to uninfected patients. Particularly, in CagA-positive patients we observed a significant reduction in sperm motility and in the fertility index, while apoptosis and necrosis were increased. In these patients, the means of systemic TNF-alpha levels were higher than those of uninfected patients. The negative influence of CagA-positive H. pylori infection on sperm quality may help to understand the role of chronic infections in reproductive disorders.

Helicobacter pylori infection and endocrine disorders: Is there a link?

Helicobacter pylori (H pylori) infection is a leading world-wide infectious disease as it affects more than half of the world population and causes chronic gastritis, peptic ulcer disease and gastric malignancies. The infection elicits a chronic cellular inflammatory response in the gastric mucosa. However, the effects of this local inflammation may not be confined solely to the digestive tract but may spread to involve extra-intestinal tissues and/or organs. Indeed, H pylori infection has been epidemiologically linked to extra-digestive conditions and diseases. In this context, it has been speculated that H pylori infection may be responsible for various endocrine disorders, such as autoimmune thyroid diseases, diabetes mellitus, dyslipidemia, obesity, osteoporosis and primary hyperparathyroidism. This is a review of the relationship between H pylori infection and these endocrine disorders.

Sperm ultrastructure and meiotic segregation in a group of patients with chronic hepatitis B and C

Little is known about the effect of chronic hepatitis B and hepatitis C on sperm quality. In this study, we analysed sperm quality from selected patients with chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infections. Semen samples were examined by light and transmission electron microscopy (TEM). TEM data were elaborated with a mathematical formula able to indicate a fertility index and the presence of the three main sperm pathologies: apoptosis, immaturity and necrosis. Meiotic chromosome segregation was investigated by fluorescence in situ hybridisation carried out on sperm nuclei, using probes for chromosomes 18, X and Y. Despite normal sperm concentration, we observed reduced motility. TEM analysis highlighted that 35.7% of patients showed generally good semen quality. However, significantly higher values of apoptosis and necrosis, compared with controls, were observed, demonstrating spermatogenetic alterations. Regarding meiotic segregation, we found an incidence of disomies similar to that observed in control samples, whereas diploidy resulted higher in HCV patients, without reaching statistical significance. In conclusion, sperm quality in the studied group was not impaired; however, apoptosis and necrosis resulted out of normal range and the fertility index was significantly lower in HCV- and HBV-infected patients versus controls.

Sperm ultrastructure and meiotic segregation in a group of patients with chronic hepatitis B and C

Little is known about the effect of chronic hepatitis B and hepatitis C on sperm quality. In this study we analysed sperm quality from selected patients with chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infections. Semen samples were examined by light and transmission electron microscopy (TEM). TEM data were elaborated with a mathematical formula able to indicate a fertility index and the presence of the three main sperm pathologies: apoptosis, immaturity and necrosis. Meiotic chromosome segregation was investigated by fluorescence in situ hybridisation carried out on sperm nuclei, using probes for chromosomes 18, X and Y. Despite normal sperm concentration, we observed reduced motility. TEM analysis highlighted that 35.7% of patients showed generally good semen quality. However, significantly higher values of apoptosis and necrosis, compared with controls, were observed, demonstrating spermatogenetic alterations. Regarding meiotic segregation, we found an incidence of disomies similar to that observed in control samples, whereas diploidy resulted higher in HCV patients, without reaching statistical significance. In conclusion, sperm quality in the studied group was not impaired, however, apoptosis and necrosis resulted out of normal range and the fertility index was significantly lower in HCV and HBV infected patients versus controls.

The plausibility of Helicobacter pylori-related infertility in Japan

The aim of the present study was to confirm the seropositive rate of Helicobacter pylori to which antibodies cross-react with spermatozoon flagella in patients with infertility. Of the 204 patients in whom the anti-H. pylori IgG antibody in serum and follicular fluids were measured, 45 (22.1%) were seropositive for H. pylori and the seropositive percentage of infertile patients without any possible cause was higher than that of patients with one or more known infertility factors [8 of 21 patients (38.3%) vs. 37 of 183 patients (20.2%), respectively], which suggests a new concept: H. pylori-related infertility.

Helicobacter pylori and extragastric diseases

Since the discovery of Helicobacter pylori, several studies have investigated the hypothetical role of this bacterium in various extragastric diseases, e.g. ischemic heart disease, idiopathic thrombocytopenic purpura, iron-deficiency anaemia, and other disorders. The majority of these studies are epidemiological or eradication trials, but there are also case reports and in-vitro studies. Idiopathic thromobocytopenic purpura is the disease that shows the strongest link with H. pylori infection. There is also evidence of a role of CagA-positive H. pylori infection in iron-deficiency anaemia and ischemic heart disease. The association between H. pylori infection and other extragastric diseases remains controversial, being mostly supported by 'case reports', small pilot studies, or just in-vitro data. Further studies are needed to identify whether there is any pathological implication for H. pylori infection in these diseases.

Eradication rate of Helicobacter pylori according to genotypes of CYP2C19, IL-1B, and TNF-A

BACKGROUND

Lansoprazole, amoxicillin, and clarithromycin are commonly used drugs for eradication of Helicobacter pylori (H. pylori). A few studies reported that the eradication rate was influenced by the functional polymorphism of CYP2C19, whose product metabolizes proton pomp inhibitors including lansoprazole.

METHODS

This study examined the eradication rate among 67 participants in the polymorphism study who visited Daiko Medical Center, Nagoya University from July 2004 to October 2005. The participants aged 20 to 69 years were classified into three group according to CYP2C19 genotype; rapid metabolizers (RM) with *1*1 genotype, intermediate metabolizers (IM) with *1*2 or *1*3 genotype, and poor metabolizers (PM) with *2*2, *2*3, or *3*3 genotype. For the genotype classification, G681A (681G for *1 and 681A for *2) and G636A (636G for *1 and 636A for *3) were genotyped by PCR with confronting two-pair primers (PCR-CTPP). They were also genotyped for IL-1B T-31C and TNF-A T-1031C by a duplex PCR-CTPP.

RESULTS

The eradication rate was 70.0% for RM, 93.9% for IM, and 85.7% for PM. The difference in the rate between RM and IM+PM was statistically significant (p=0.025). The eradication rate was highest for those with IL-1B -31CC; the p value was marginal among the whole subjects (chi2=3.78, p=0.05) and not significant among the RM group (chi2=1.60, p=0.21). The genotypes of TNF-A T-1031C had no associations with the eradication rate. But among the RM group, the odd ratio (OR) of the TNF-A CT for the eradication rate relative to TT was marginally reduced (OR=0.05, 95% confidence interval, 0.002-1.19).

CONCLUSIONS

The present study confirmed the low eradication rate for RM. The reproduced finding provides evidence that the CYP2C19 genotype is useful to predict the success of the treatment. For the RM group, alternative regimens expected to be with a higher eradication rate will be recommended, especially to those with the TNF-A -1031C allele.

Is Helicobacter pylori a pathogenic agent of the cervix uteri?

BACKGROUND

Helicobacter pylori is a gram-negative, microaerophilic rod-shaped bacterium that lives beneath the gastric mucosal layers, on the surface of epithelial cells. Gastric infection with this organism causes inflammation of the gastric mucosa, which can lead to gastritis, duodenal or gastric ulcers and even in rare cases to gastric carcinoma or MALT lymphoma. Approximately 50% of the population of the entire world is believed to be infected with H. pylori, but the exact route of transmission is still uncertain. It has been speculated that the cervix, with its endocervical columnar epithelium and acidic mucous layer, might provide a suitable environment for H. pylori. H. pylori might be a pathogenic agent for cervical infection. In order to address this issue we studied H. pylori in the endocervical tissue.

METHODS

To investigate our hypothesis, we examined cervical tissue using PCR, culture, and Gram-stain. Thirty-three cervices from women who underwent total hysterectomy for noninvasive non-cervical benign uterine diseases were analyzed in this study. Twenty-one patients had cervicitis and 12 patients were included as controls.

RESULTS

Of the 29 patients studied, none showed evidence of H. pylori infection. H. pylori was not detected by PCR, histology, or culture.

CONCLUSIONS

We could not detect H. pylori in the cervix of patients with cervicitis. H. pylori-infected patients' cervices remain to be investigated, and a larger study is needed to draw firm conclusions.

The infectious etiology of the antiphospholipid syndrome: links between infection and autoimmunity

Like many other autoimmune diseases, the antiphospholipid syndrome (APS) is considered as of a multifactorial etiology, mainly genetic susceptibility coinciding with environmental triggers, of which infectious agents are considered most prominent. Different clinical and experimental studies of the beta2 glycoprotein I (beta 2 GPI) molecule, one of the target autoantigens in APS, have linked infection to the development of APS. Using a peptide phage library, it has been shown that target epitopes of beta 2 GPI share similarities with common infectious pathogens. Also, circulating anti-beta 2 GPI antibodies have been identified in the sera of patients with different infectious conditions, and have been associated with various clinical APS manifestations. Molecular mimicry as a key mechanism linking infection and APS has been demonstrated in experimental models. In these studies, APS was induced by immunization of mice to various microbial pathogens. Anti-beta 2 GPI titers were found to be especially high following immunization with Haemophilus influenzae, Neisseria gonorrheae or tetanus toxoid. These findings contribute greatly to the understanding of APS pathogenesis, as well as create new directions for therapy modalities, namely specific peptide toleragens and antimicrobial treatment.

Beta-2-glycoprotein-I, infections, antiphospholipid syndrome and therapeutic considerations

Evidence supports the association between infectious agents, antiphospholipid syndrome (APS), and the presence of antiphospholipid antibodies and anti-beta2-glycoprotein-I (beta2GPI) antibodies. Several mechanisms have been proposed to explain the role of bacteria/viruses in induction of an autoimmune condition, such as molecular mimicry between structures of a pathogen and self antigen and bystander activation or bacterial/viral superantigens. Protein databases reveal high homologies between the beta2GPI-related synthetic peptides and infectious agents. Studies employing experimental APS models proved molecular mimicry between beta2GPI-related synthetic peptides, which serve as target epitopes for anti-beta2GPI Abs, and structures within bacteria, viruses (e.g., CMV), and tetanus toxoid. Any explanation of how microbial infections might induce APS must take into account the genetic predisposition. In this paper, we discuss the association of antiphospholipid antibodies, infectious states, and molecular mimicry as a proposed mechanism for development of APS.

Helicobacter pylori infection negatively influences pregnancy outcome in a mouse model

BACKGROUND

Helicobacter pylori infects the human stomach, causing gastritis, peptic ulcer, and gastric cancer. H. pylori infection has also been related to extra-gastric disorders. We investigated whether H. pylori infection can influence pregnancy in a murine model.

METHODS

Female CD1 mice were infected with the H. pylori SPM326 strain before mating, and then assessed throughout pregnancy for embryo/fetus characteristics and histopathological changes of the endometrium.

RESULTS

Infected mice showed higher numbers of resorption and lower fetal weights than noninfected controls. These pathological phenomena were accompanied by macrophage activation, and increases both of CD4+ and CD8+ lymphocytes and of interferon-gamma and major histocompatibility complex class II expression at the endometrial level, as evaluated by immunohistochemistry.

DISCUSSION

During pregnancy, preferential induction of Th2-type cytokines downregulates Th1-type responses, allowing fetal survival. Our results suggest that H. pylori infection can induce activation of resident uterine immune cells and/or recruitment of cells at the endometrial level. It can be hypothesized that the local Th1-type response induced by H. pylori infection could alter the systemic Th1/Th2-type cytokine balance at sites under particular physiopathological conditions of active tissue and/or vascular formation, such as pregnancy.

CONCLUSIONS

This is the first evidence in an animal model of the possible influence of H. pylori infection on pregnancy. Further work is required on its mechanism and its relevance for humans.

Construction and expression of the fusion gene of H pylori HspA subunit and E.coli heat-labile enterotoxin B subunit

AIM

To construct and express the fusion gene of H pylori heat shock protein A subunit (HspA) and E.coli heat-labile enterotoxin B subunit (LTB), and analyse the biologic and immunologic characteristics of the fusion protein.

METHODS

HspA gene was amplified from H pylori chromosome by PCR. The gene was cloned into plasmid pPLtB and the fusion gene of H pylori urease B subunit (HspA) and E.coli heat-labile enterotoxin B subunit (LTB) was constructed, and then LTB-HspA recombinant protein was expressed in E.coli JM109.

RESULTS

LtB-HspA fusion gene was found to be 684 base pairs and encode the recombinant fusion protein, which was composed of 228 amino acid residues. SDS-PAGE and Western blotting analysis showed that the recombinant fusion protein had a molecular weight of 25kD and a positive reaction with the serum from H pylori-infected patients. ELISA analysis showed that LTB protein existed in the fusion protein. At the same time, fusion protein kept the character of binding with LTB receptor-ganglioside GM1.

CONCLUSION

LTB-HspA recombinant protein may be used for research of genetically engineered H pylori vaccine.

Helicobacter pylori and extragastric diseases -- other helicobacters

The role of Helicobacter pylori infection is explored in more and more extragastric diseases without definite proof in most of the studies, except possibly some hematologic diseases. In cardiovascular diseases, including stroke, the presence of CagA positive strains may be involved. The possible role of helicobacters in hepatobiliary diseases goes beyond that of H. pylori to involve enterohepatic helicobacters. New Helicobacter species are regularly described and molecular methods are developed to improve their detection. Helicobacter felis remains the major species to be used in animal models of Helicobacter infection.