Differentiation of the human PAX7-positive myogenic precursors/satellite cell lineage in vitro

Satellite cells (SC) are muscle stem cells that can regenerate adult muscles upon injury. Most SC originate from PAX7+ myogenic precursors set aside during development. Although myogenesis has been studied in mouse and chicken embryos, little is known about human muscle development. Here, we report the generation of human induced pluripotent stem cell (iPSC) reporter lines in which fluorescent proteins have been introduced into the PAX7 and MYOG loci. We use single cell RNA sequencing to analyze the developmental trajectory of the iPSC-derived PAX7+ myogenic precursors. We show that the PAX7+ cells generated in culture can produce myofibers and self-renew in vitro and in vivo Together, we demonstrate that cells exhibiting characteristics of human fetal satellite cells can be produced in vitro from iPSC, opening interesting avenues for muscular dystrophy cell therapy. This work provides significant insights into the development of the human myogenic lineage.

Recapitulating early development of mouse musculoskeletal precursors of the paraxial mesoderm in vitro

Body skeletal muscles derive from the paraxial mesoderm, which forms in the posterior region of the embryo. Using microarrays, we characterize novel mouse presomitic mesoderm (PSM) markers and show that, unlike the abrupt transcriptome reorganization of the PSM, neural tube differentiation is accompanied by progressive transcriptome changes. The early paraxial mesoderm differentiation stages can be efficiently recapitulated in vitro using mouse and human pluripotent stem cells. While Wnt activation alone can induce posterior PSM markers, acquisition of a committed PSM fate and efficient differentiation into anterior PSM Pax3+ identity further requires BMP inhibition to prevent progenitors from drifting to a lateral plate mesoderm fate. When transplanted into injured adult muscle, these precursors generated large numbers of immature muscle fibers. Furthermore, exposing these mouse PSM-like cells to a brief FGF inhibition step followed by culture in horse serum-containing medium allows efficient recapitulation of the myogenic program to generate myotubes and associated Pax7+ cells. This protocol results in improved in vitro differentiation and maturation of mouse muscle fibers over serum-free protocols and enables the study of myogenic cell fusion and satellite cell differentiation.

Generation of human muscle fibers and satellite-like cells from human pluripotent stem cells in vitro

Progress toward finding a cure for muscle diseases has been slow because of the absence of relevant cellular models and the lack of a reliable source of muscle progenitors for biomedical investigation. Here we report an optimized serum-free differentiation protocol to efficiently produce striated, millimeter-long muscle fibers together with satellite-like cells from human pluripotent stem cells (hPSCs) in vitro. By mimicking key signaling events leading to muscle formation in the embryo, in particular the dual modulation of Wnt and bone morphogenetic protein (BMP) pathway signaling, this directed differentiation protocol avoids the requirement for genetic modifications or cell sorting. Robust myogenesis can be achieved in vitro within 1 month by personnel experienced in hPSC culture. The differentiating culture can be subcultured to produce large amounts of myogenic progenitors amenable to numerous downstream applications. Beyond the study of myogenesis, this differentiation method offers an attractive platform for the development of relevant in vitro models of muscle dystrophies and drug screening strategies, as well as providing a source of cells for tissue engineering and cell therapy approaches.

Differentiation of pluripotent stem cells to muscle fiber to model Duchenne muscular dystrophy

During embryonic development, skeletal muscles arise from somites, which derive from the presomitic mesoderm (PSM). Using PSM development as a guide, we establish conditions for the differentiation of monolayer cultures of mouse embryonic stem (ES) cells into PSM-like cells without the introduction of transgenes or cell sorting. We show that primary and secondary skeletal myogenesis can be recapitulated in vitro from the PSM-like cells, providing an efficient, serum-free protocol for the generation of striated, contractile fibers from mouse and human pluripotent cells. The mouse ES cells also differentiate into Pax7(+) cells with satellite cell characteristics, including the ability to form dystrophin(+) fibers when grafted into muscles of dystrophin-deficient mdx mice, a model of Duchenne muscular dystrophy (DMD). Fibers derived from ES cells of mdx mice exhibit an abnormal branched phenotype resembling that described in vivo, thus providing an attractive model to study the origin of the pathological defects associated with DMD.

Anticorps anti-ovaires et fécondation in vitro : cause ou conséquence ?

OBJECTIVES

To assess anti-ovarian antibodies (AOA) in serum samples at various times of in vitro fertilization (IVF) attempts to determine whether ovarian stimulation could result in the production of such autoantibodies in women.

PATIENTS AND METHODS

Prospective study on 134 patients and 138 IVF cycles using a classical long protocol. For each attempt, four serum samples were obtained, respectively, at the onset of downrelation (S1), end of downregulation (S13), after 7 days of follicular stimulation (S21) and the day of follicular puncture (SP). Five hundred and fifty two samples were tested with an enzyme-linked immunosorbent assay for three isotypes (IgG, IgA, IgM) of AOA.

RESULTS

In the whole group, mean concentrations of AOA for each isotype were compared group by group: S1-S13, S1-S21, S1-SP, S13-S21, S13-SP, S21-SP. Not any significant difference was observed whatever the isotype considered.

DISCUSSION AND CONCLUSION

This study shows the absence of influence of endogenous or exogenous ovarian stimulation by gonadotropins on anti-ovarian autoimmunity.

Specific IgA to lactic acid bacteria in feces of children consuming milk fermented by yoghurt symbiosis and Lactobacillus casei (Danone strain DN 114 001)

An immunoreactive role of lactic acid bacteria established in animals has seldom been investigated in humans. In a large-scale clinical study, children from day-care centers received either yoghurt (Y), milk fermented by yoghurt symbiosis and Lactobacillus casei (DN 114 001) (YC), or gelified milk (GM) as diet supplements during two 30-day supplementation periods separated by one 30-day period without supplementation. Feces samples were collected before, during, and after the 2nd supplementation period. Proteins were extracted in a buffer containing enzymatic inhibitors. IgA levels were assessed and adjusted to the weight of feces samples. Specific IgA to lactic acid bacteria strains (Streptococcus thermophilus 8901A, 8902A; Lactobacillus bulgaricus; Lactobacillus casei) present in Y and YC were assayed in ELISA and adjusted to individual IgA levels. Mean levels of fecal IgA were within reported ranges for pediatric populations of similar age. IgA levels decreased significantly but transiently in children receiving Y, and increased significantly in children receiving GM, but did not vary in the group of children who were given YC. Specific IgA to the 4 strains tested increased significantly during the supplementation period only in the group of children receiving GM, while it was transient and not significant in children receiving YC. No variation was noted in children given Y Specific IgA to lactic acid bacteria can be assayed in feces. Supplementation with fermented milks might induce a mucosal tolerance to environmental flora.

An immunoreactive peptide of the FSH involved in autoimmune infertility

The purpose of this study was to identify autoantigens contained in human ovary extracts. Serum samples from 36 infertile women with anti-ovary antibodies as detected with an ELISA technique were tested in Western blot against human ovary extracts. A reactive protein with a molecular mass matching that of the FSH was detected in 34 cases. These serum samples also reacted strongly in Western blot and ELISA with purified FSH and, in immunofluorescence, with pituitary cells. Using the Pepscan approach, with overlapping peptides matching the amino acid sequence of the human FSH beta-chain, several immunoreactive regions were evidenced. The 78-93 amino acid sequence of the human FSH beta-chain appeared as one of the major epitopes. Synthetic peptides of this region were prepared and demonstrated to react with human serum samples from women with anti-ovary antibodies. These data demonstrate that FSH can be an autoantigen, recognized by autoantibodies associated with infertility.

Polyisotypic antipeanut-specific humoral responses in peanut-allergic individuals

BACKGROUND

Peanut-containing food products may induce severe clinical reactions in sensitized subjects, and high levels of antipeanut IgE have been reported in the literature. Immunotherapy, proposed for the prevention of severe accidents, is often ill-tolerated and only partly efficient. This could be due to the spontaneous development of polyisotypic antipeanut antibodies.

OBJECTIVE

To appreciate the presence and reactivity of other isotypes other than IgE of peanut-specific antibodies in serum samples from peanut-sensitized subjects.

METHODS

Serum samples were obtained from 20 non-sensitized subjects and 23 sensitized patients divided in three groups according to their response to peanut oral challenge (no response or response to high or low doses, respectively). Peanut-specific IgG, IgG subclasses, IgA and IgM were assayed using an ELISA, and their reactivity against peanut proteins tested using Western Blot.

RESULTS

A large dispersion of antipeanut antibody levels was observed in the three groups of patients, high levels of IgG, IgG1, IgG4 and IgA usually correlating with highly positive radioallergosorbent test (RAST). Such high levels were observed at onset in four patients who underwent peanut immunotherapy who had side effects and poor efficiency. Western blotting demonstrated that the polyisotypic response observed was directed to several peanut antigens, including the major allergens, Ara h1 and Ara h2.

CONCLUSION

Peanut-sensitized patients who spontaneously develop specific IgE, display polyisotypic-specific antibody responses, whatever their response to oral challenge. This might explain the poor efficiency of peanut rush immunotherapy attempts.

[Activated protein C resistance and cardiolipin antibodies in leg ulcers]

BACKGROUND

We conducted a prospective study to determine the prevalence of activated protein C resistance and anticardiolipin antibodies in leg ulcers, whatever venous, arterial or arteriovenous.

PATIENTS AND METHODS

One hundred fifteen patients hospitalized for leg ulcers, without antiphospholipid syndrome were included. The vascular abnormalities were studied by clinical examination, Doppler, duplex Doppler and, when required, arteriography. Activated protein C resistance was isolated by a "classic" test (normalized APTT ratio in PCa presence or absence) and by a "second generation test" (by preliminary dilution with deficient factor V plasma). All patients with abnormal results on the second test were screened for the factor V Leiden (by PCR amplication with use of restriction enzymes). Anticardiolipin antibodies were investigated with an ELISA method with Harris standards as reference, in which the positive threshold was established at 20 units.

RESULTS

Among these 115 patients, 50 venous (43.5 p. 100), 23 arterial (20 p. 100), 42 arteriovenous (36.5 p. 100) leg ulcers were identified. Activated protein C resistance was isolated in 12 cases (10.4 p. 100) (heterozygous carriers): 7 venous ulcers, 3 arteriovenous, 2 arterial. Anticardiolipin antibodies were measured at significant level in 49 cases (42.6 p. 100): 21 venous ulcers, 18 arteriovenous, 10 arterial.

DISCUSSION

In this study, there was no statistical difference between the activated protein C resistance prevalence in leg ulcers when compared with Lorraine population (p=0.27). Factor V Leiden or anticardiolipin antibodies abnormalities were isolated in 56 cases (48.7 p. 100) without statistical difference between the 3 types of ulcers. Finally, the pathophysiology of venous, arterial and arteriovenous leg ulcers remains complex, suggesting several coagulation perturbations.

[Polyclonal T lymphocyte proliferation in drug lymphocyte activation test]

BACKGROUND

We examined the clonality of the specific T cell reaction activated with specific drug antigens in patients with a positive lymphocyte activation test.

PATIENTS AND METHODS

Ten patients were investigated. Their clinical features suggested drug allergy. Six weeks after a skin reaction, skin tests and lymphocyte activation tests were run. For each lymphocyte activation test, we explored the clonality of the T cell proliferation by examining the VJ rearrangement of the TCR gamma locus using polymerase chain reaction and denaturing gradient gel electrophoresis.

RESULTS

All samples gave positive lymphocyte activation tests proving in vitro polyclonal T cell proliferation in reaction to a drug. There was no difference in clonality between the pilot lymphocyte activation test and the lymphocyte activation test after stimulation with phytohemagglutinin or with the drug antigen.

DISCUSSION

Our findings show that in vitro T cell proliferation induced by a specific drug antigen as disclosed by the lymphocyte activation test is a polyclonal or oligoclonal cell proliferation. This lack of production of a preferential T clone in a T cell-mediated immune drug reaction implies that many T lymphocytes can recognize the antigen and be stimulated by the same drug.

Prevalence, specificity and significance of ovarian antibodies during spontaneous premature ovarian failure

Autoimmunity may be involved in idiopathic premature ovarian failure (POF). However, the frequency, physiopathology and potential reversibility of autoimmune oophoritis needs clarification. Using an ELISA against whole tissue homogenate as antigen, from human ovaries at different ages, positive circulating ovarian antibodies (AOA) were found in 59% of patients with primitive idiopathic POF (27/46); 20/27 were positive for IgG isotype, 9/27 for IgM and 8/27 for IgA. Specificity of AOA was examined (i) by comparison to different control groups; mean values of the three subclasses of immunoglobins were significantly higher in POF women than in normally cycling fertile young women (n = 23) and fertile young men (n = 17), in untreated Grave's disease (n = 35) or in women with positive antinuclear factor (n = 25); and (ii) by assessing possible cross-reaction; only six out of the 27 positive sera reacted with other tissues (thyroid, pancreas, adrenal), including four clinical polyendocrinopathies. Significance of AOA was explored (i) by comparison with postmenopausal women (n = 40) and older women (n = 15), who did not have enhanced ratios of AOA, thereby excluding a potential role of high FSH values; (ii) by analysing the factors time and surgery; no relation could be found either with the duration of amenorrhoea (6 months to 21 years) or with the history of an ovarian biopsy (12/47) in the absence of any associated pelvic surgery; and (iii) by screening for other immunological factors; familial or personal autoimmune disease (8/46), HLA DR3 (10/42), HLA DR4 (11/42), associated autoantibodies (thyroperoxidase, adrenal, beta islets, parathyroid, DNA, smooth muscles) (12/42). If one positive AOA isotype was present, a second immunological factor was found in 45% of cases. Spontaneous pregnancies during oestrogen therapy occurred in four cases, including three women with positive AOA. Circulating AOA detected by an ELISA may represent a practical and suitable marker for diagnosis of POF. Its use for prognosis and rational treatment needs further evaluation.

Specific humoral immune responses in 12 cases of food sensitization to sesame seed

BACKGROUND

Hypersensitivity to sesame seeds is becoming increasingly frequent, probably owing to the larger use of this compound in international food.

OBJECTIVES

This study investigated serum responses of 12 sesame sensitized patients (seven with food allergy, five with food sensitization), to a sesame protein extract, and attempted at identifying sesame major antigens.

METHODS

Sesame protein extracts were prepared from black, white and brown sesame seeds. Electrophoretic analysis showed similar protein patterns in the three extracts, and proper preservation of the proteins integrity. The brown sesame extract was used to set-up an ELISA assay and measure serum levels of antisesame IgG, IgA, IgM and IgE in 12 samples from sesame-sensitized individuals and six controls. It also allowed to perform western blot analyses in order to investigate the molecular weight of sesame proteins recognized by IgG, IgA and IgE.

RESULTS

Nineteen protein bands were observed upon polyacrylamide gel electrophoresis of the sesame protein extracts. Using this whole extract in ELISA, significant antisesame IgG, IgA and IgE-responses were observed in the serum of sensitized individuals, different from the lower signals obtained with control samples. Western blot analysis demonstrated highly polymorphic IgG and IgA responses and a more restricted IgE response pattern, suggesting that two proteins, respectively, 14 kDa and 25 kDa are mostly involved in sesame IgE-dependent hypersensitivity, the 25 kDa band presenting several characteristics of a major allergen.

CONCLUSIONS

This study reports novel information on the possible involvement of a 25 kDa sesame protein in IgE-dependent hypersensitivity to sesame seeds.

Comparative assessment of phospholipid-binding antibodies indicates limited overlapping

The implication of autoantibodies with anticoagulant and/or so-called antiphospholipid activities, under clinical circumstances with vascular obliteration, has led to the development of various types of tests allowing their detection. The most used tests involve investigation of the presence of an anticoagulant effect and of anticardiolipin IgG. It has also been proposed that the reactivity of patient samples toward other phospholipids or proteins be tested, but it remains difficult to appreciate which tests are redundant or complementary. Here we investigated whether the dissociation or association of anticoagulant and anticardiolipin correlated with specific ELISA reactivity to five other phospholipids: phosphatidylserine, phosphatidylinositol, phosphatidic acid, phosphatidylcholine, and phosphatidylethanolamine. The study was performed with 70 samples, evenly partitioned as positive for either anticardiolipin antibodies or anticoagulant effect, or both. Our data clearly confirm that cardiolipin reactivity is an individual entity, likely to be complementary to other assays. Neither anticardiolipin nor anticoagulant levels correlated with assays investigating antibody levels toward the five other phospholipids, although higher mean levels were noted when both lupus anticoagulant and anticardiolipin antibodies are present. Individual patterns were evidenced in all groups. These data support the interest of current and further studies exploring the clinical relevance of individual reactivities to phospholipids.

Ovarian autoimmunity and corticotherapy in an in-vitro fertilization attempt

This case report describes a successful pregnancy and delivery in a woman presenting with ovarian autoimmunity who had previously been involved in two unsuccessful in-vitro fertilization (IVF) attempts. Ten days before a third attempt, she began a regimen of 25 mg per day of prednisolone which was continued throughout the whole IVF protocol. Ovulation was induced by human menopausal gonadotrophin. After administration of 5000 IU of human chorionic gonadotrophin, 18 oocytes were collected. At 48 h after insemination with the patient's husband's spermatozoa, four 4-cell pre-embryos were transferred. A singleton pregnancy developed and led to the birth of a girl who is doing well 10 months later.

Isoelectric restriction of human immunoglobulin isotypes

The partition of human serum immunoglobulins along a pH gradient of ampholynes was investigated using the recently developed method of preparative isoelectrofocusing. Each isotype was demonstrated to display a specific pI range, with limited overlapping. IgA appear to be the most acidic serum immunoglobulins while IgG are clearly basic.

Humoral immune responses of workers occupationally exposed to wheat flour

Wheat flour is a complex organic dust likely to induce immune responses when inhaled in work environment conditions. We compared the humoral status of 159 exposed workers from 11 flour mills and one industrial bakery with that of 41 workers from a salt factory. IgG, IgA, and IgM levels of antibodies to whole flour and to gliadin were assayed using ELISA tests in serum and saliva samples. Serum levels of IgG and IgA to both antigens were significantly higher (p < 0.0001) in occupationally exposed workers. Exposed workers had significantly higher levels of salivary IgG (p = 0.005) and IgA (p < 0.0001) to whole flour and of salivary IgG (p = 0.0005) to gliadin. In both groups, similar levels of anti-gliadin salivary IgA antibodies were observed. These data suggest that occupational exposure to wheat flour triggers specific immune responses, most likely through stimulation of the mucosal immune system. The presence of significant levels of serum antibodies, however, indicates that a systemic immunologic response is also present among exposed individuals.

Antibodies to choroid plexus in senile dementia of Alzheimer's type

AIMS

To investigate whether autoantibodies to choroid plexus are present in human senile dementia.

METHODS

Serum samples from 40 elderly people presenting with characteristic, diagnostic criteria of senile dementia of Alzheimer's type and 20 age matched healthy controls were tested by indirect immunofluorescence for the presence of autoantibodies to choroid plexuses, using frozen sections of rat or human fetal brain tissue.

RESULTS

Significant labelling of choroid plexus basement membrane was observed in 17 of the 40 samples from patients with senile dementia; in the control series one sample of rat but not human plexus labelled positively (p < 0.01).

CONCLUSIONS

The antibodies identified in this series of patients with Alzheimer's disease suggest that autoimmune mechanisms might be responsible for some of the changes in cerebrospinal fluid production described in this disorder.

Anti-ovary antibodies after attempts at human in vitro fertilization induced by follicular puncture rather than hormonal stimulation

Anti-ovary antibodies (AOA) have been detected in serum samples of women undergoing in vitro fertilization (IVF). High concentrations of these antibodies have been found in women who have had several IVF attempts and they appear to correlate with reduced chances of pregnancy. In this paper, AOA were assayed sequentially in a series of 140 IVF candidates to investigate the respective roles of hormonal stimulation and follicular puncture in inducing the autoimmune response. Serum was obtained 8 days after the beginning of ovarian human menopausal gonadotrophin (hMG) stimulation, then 15 days after follicular puncture. Significantly higher concentrations of IgG (P < 0.0001) AOA were observed in the second series of samples than in the first, suggesting that ovarian trauma and not hormonal stimulation is responsible for triggering antibody production. In the whole group, there was a negative correlation between IgM levels after puncture and oocyte numbers (P < 0.05). Among 'immune-responder' women, the concentrations of IgA AOA (P = 0.01) in the first sample, and of IgG (P = 0.01) or IgA AOA (P < 0.05) in the second, correlated with fewer oocytes after stimulation. There was no variation in the mean concentrations of AOA in women who achieved pregnancy.

Expression of the T-cell receptor in HIV infection

Expression of the T-cell receptor (TCR) was investigated on peripheral lymphocytes in 270 samples from HIV+ patients at different stages of infection. TCR is composed either of an alpha and a beta chain, or, in a smaller subset of T-cells, of a gamma and a delta chain, closely associated with CD3. The numbers and percentages of positive cells were established using monoclonals to the alpha and delta chains of TCR. The values of alpha-TCR positive cells were constantly lower than those observed for CD3, with a mean of 53% (+/- 19%) versus 66% (+/- 17) respectively for asymptomatic patients or patients with persistent generalized lymphadenopathy, and of 36% (+/- 19) versus 46% (+/- 21) for patients with AIDS disease. There was no compensatory increase in the number of cells expressing delta-TCR. These data demonstrate a new alteration of the immune system in HIV infection, which appears to occur early in this disease.

Antiovary antibodies, repeated attempts, and outcome of in vitro fertilization

OBJECTIVE

To determine whether the microtrauma induced by repeated puncture of ovarian follicles could result in the production of autoantibodies in women submitted to in vitro fertilization (IVF).

DESIGN

Antiovarian antibodies were assayed in serum samples obtained from women engaged in IVF and in serum samples from healthy controls.

SETTING

Blood samples were obtained after oocyte collection in the local hospital's IVF unit.

PATIENTS

One hundred ten women undergoing IVF entered the study. Oocyte division, numbers of embryos, and pregnancy were recorded for each woman. Control samples were from 40 individuals with no sign of autoimmune disorder.

INTERVENTIONS

Antiovarian antibodies were assayed in indirect immunofluorescence and enzyme-linked immunosorbent assay (ELISA) using human ovary as antigen. Specific immunoglobulin (Ig)G, IgA, and IgM were tested separately in an ELISA.

MAIN OUTCOME MEASURE

Antiovarian antibody levels were compared between patients and controls and correlated with the subsequent results of IVF.

RESULTS

Significantly higher levels of IgG, IgA, and IgM antiovarian antibodies were observed in the group of IVF women (P less than 0.001). IgM antiovarian antibodies correlated with a lower number of embryos (P less than 0.001) and IVF failure (P less than 0.05).

CONCLUSIONS

These data suggest that ovarian trauma may lead to the production of autoantibodies.

Dynamic changes in soluble interleukin-2 receptor levels during treatment of Graves' disease. Correlation with disease activity

The activation of T lymphocyte is accompanied by the release of soluble interleukin-2 receptors (sIL-2R) which can be assessed in biological fluids. A prospective study of the dynamic changes in sIL-2R levels was performed in the serum of 10 patients undergoing a medical treatment for Graves' disease. All patients received carbimazole during the study and, when necessary, L-thyroxine to compensate hypothyroidism. sIL-2R levels were measured before (M0) and after the 1st (M1), 3rd (M3) and 6th month (M6) of treatment. The levels of sIL-2R were high at M0 and M1, and decreased significantly between M1 and M3 (p = 0.03). At M0, the levels of sIL-2R were highly correlated with triiodothyronine (T3) levels (p = 0.0003), early [131I] uptake (p = 0.007) and, to a lesser degree, with anti-thyrotropin receptor antibody levels (p = 0.02). At M6, no correlation was found anymore. We conclude that sIL-2R levels are increased in patients with untreated Graves' disease. They are highly correlated with the markers of Graves' disease activity and decrease during medical treatment.

CD4-like molecules in human sperm

The expression of a molecule recognized by CD4 monoclonal antibodies was investigated on human sperm using immunolabelling, biochemical and immunochemical methods. Flow cytometry detected a significant fluorescence signal. SDS-PAGE analysis and Western blotting identified a molecule of 60 kDa, consistent with a CD4-like structure as confirmed after selective immunoseparation. Additional bands reacting with anti-CD4 were found in sperm extracts (73 kDa) and seminal fluid (90 kDa). These data indicate that sperm express a molecule similar to the receptor for HIV described on mononuclear cells.

Isotype evolution in the follow-up study of patients with Campylobacter pylori associated gastritis

Four sequential immuno-assays were performed from May to November 1988 to follow the levels of IgG, IgA and IgM to Campylobacter pylori in 16 infected patients with histologically proven gastritis, among which 12 received appropriate therapy. Histopathological examination of antral biopsies, bacteriological cultures and urease tests were performed on each occasion when serum was tested for antibodies to C. pylori. The detection and quantitative assessment of the various isotypes to this bacterium proved valuable to appreciate the response to therapy with, in case of success, a steady decrease of antibodies levels concomitant with clinical improvement.