Sclerostin and bone turnover markers response to cycling and running at the same moderate-to-vigorous exercise intensity in healthy men.

BACKGROUND: Recreational cycling is a popular activity which stimulates and improves cardiovascular fitness. The corresponding benefits for bone are unclear. PURPOSE: This study examined the effect of running (high-impact) vs. cycling (low-impact), at the same moderate-to-vigorous exercise intensity, on markers of bone formation (N-terminal propeptide of type I collagen, PINP) and bone resorption (C-telopeptide of type I collagen, CTX-1), a non-collagenous bone remodeling marker (osteocalcin), as well as bone-modulating factors, including parathyroid hormone (PTH), irisin (myokine) and sclerostin (osteokine). METHODS: Thirteen healthy men (23.7 ± 1.0 y) performed two progressive exercise tests to exhaustion (peak VO2) on a cycle ergometer (CE) and on a treadmill (TM). On subsequent separate days, in randomized order, participants performed 30-min continuous running or cycling at 70% heart rate reserve (HRR). Blood was drawn before, immediately post- and 1 h into recovery. RESULTS: PTH transiently increased (CE, 51.7%; TM, 50.6%) immediately after exercise in both exercise modes. Sclerostin levels increased following running only (27.7%). Irisin increased following both running and cycling. In both exercise modes, CTX-1 decreased immediately after exercise, with no significant change in PINP and osteocalcin. CONCLUSION: At the same moderate-to-vigorous exercise intensity, running appears to result in a greater transient sclerostin response compared with cycling, while the responses of bone markers, PTH and irisin are similar. The longer-term implications of this differential bone response need to be further examined.

Potential Immunomodulatory Role of Specific Anticytomegalovirus Intravenous Immunoglobulin in Heart Recipients.

BACKGROUND: Specific anticytomegalovirus (anti-CMV) intravenous immunoglobulin (IVIG) has the potential to influence the immune response, but its complex mode of action has not been well evaluated. METHODS: An immunologic study of 6 CMV-seronegative heart transplant patients receiving anti-CMV prophylaxis with the use of ganciclovir and CMV-IVIG (150 mg/kg within 24 hours after transplantation and 100 mg/kg on days 2, 7, 14, 22, 35, 56, and 77 after transplantation) was performed in a single center. Lymphocyte subsets were evaluated by means of 4-color flow cytometry at the time of inclusion in the waiting list and at 3 months after transplantation. RESULTS: High-risk heart recipients receiving CMV-IVIG showed a clear reduction in the frequency of activated CD4+CD38+DR+ T-helper cells at 3 months after transplantation compared with a group of 27 untreated control subjects who received only anti-CMV prophylaxis with the use of ganciclovir. In this study, an increase of CD19+CD27-IgM+IgD+ naïve B cells was also observed in seronegative recipients after prophylaxis with the use of CMV-IVIG but not in control subjects. None of the CMV-IVIG-treated recipients developed acute cellular rejection during the 1st 6 months after transplantation. CONCLUSIONS: The immune modulation of activated CD4+ lymphocyte and of naïve B-cell subsets after CMV-IVIG use should be further evaluated in future prospective studies with higher numbers of patients.

Audit of the use of intravenous immunoglobulin for antibody deficiencies in a Clinical Immunology Unit

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Evaluation of an immunological score to assess the risk of severe infection in heart recipients.

BACKGROUND: We previously reported how specific humoral and cellular immunological markers that are readily available in clinical practice can be used to identify heart transplant recipients (HTR) at risk of developing severe infections. In this study, we perform an extended analysis to identify immunological profiles that could prove to be superior to individual markers in assessing the risk of infection early after heart transplantation. METHODS: In a prospective follow-up study, we evaluated 100 HTR at 1 week after transplantation. Laboratory tests included determination of immunoglobulin (Ig) levels (IgG, IgA, IgM), complement factors (C3 and C4), and lymphocyte subsets (CD3+, CD4+, CD8+ T cells, B cells, and natural killer [NK] cells). The prevalence of infection during the first 3 months was registered at scheduled visits after transplantation. Severe infections were defined as all infections requiring hospitalization and intravenous antimicrobial therapy. RESULTS: During follow-up, 33 patients (33%) developed severe infections. The individual risk factors of severe infection, according to the Cox regression analysis, were as follows: IgG <600 mg/dL (hazard ratio [HR], 2.41; 95% confidence interval [CI], 1.21-4.78; P = 0.012), C3 <80 mg/dL (HR, 4.65; 95% CI, 2.31-9.38; P < 0.0001), C4 <18 mg/dL (HR 2.30, 95% CI, 1.15-4.59; P = 0.018), NK count <30 cells/µL (HR 4.07, 95% CI, 1.76-9.38; P = 0.001), and CD4 count <350 cells/µL (HR, 3.04; 95% CI, 1.47-6.28; P = 0.0027). An immunological score was created. HRs were used to determine the number of points assigned to each of the 5 previously mentioned individual risk factors. The score was obtained from the sum of these factors. In the multivariate Cox regression analysis, the immunological score was useful for identifying patients at risk of infection and was the only variable that maintained a significant association with the development of infection, after adjustment for the 5 individual factors. CONCLUSION: Patients with an immunological score ≥13 were at the highest risk of severe infections (HR, 9.29; 95% CI, 4.57-18.90; P < 0.0001). This score remained significantly associated with the risk of severe infection after adjustment for clinical risk factors of infection. An immunological score was useful for identifying HTR at risk of developing severe infections. If this score is validated in multicenter studies, it could be easily introduced into clinical practice.

Flow cytometry analysis with a new FITC-conjugated monoclonal antibody-3E12 for HLA-B*57:01 rapid screening in prevention of abacavir hypersensitivity in HIV-1-infected patients.

BACKGROUND: Rapid screening for the detection of HLA-B*57:01 in the prevention of abacavir hypersensitivity in HIV-1-infected patients is a hallmark for clinical services. OBJECTIVE: The aim of this work was to analyze the utility of flow cytometry with a new FITC-conjugated B-17 monoclonal antibody (mAb3E12) for HLA-B*57:01 screening in a Spanish cohort of 577 HIV-1+ individuals. METHODS: Cryopreserved peripheral blood mononuclear cell samples from HIV-1+ individuals were analyzed by flow cytometry with the mAb 3E12 that recognizes both HLA-B*57 and HLA-B*58 alleles (members of the group specificity, HLA-B17). Patients' DNA samples had been previously typed for HLA-B*57:01 with PCR-SSO or PCR-SSP and additional DNA sequencing (EPI Study). The results obtained by flow cytometry were compared with the results obtained by the DNA-PCR techniques. RESULTS: By flow cytometry, 46 samples (7.97%) were positive for HLA-B17, 530 (91.86%) were negative, and 1 (0.17%) was undetermined. All samples found negative by flow cytometry were negative for HLA-B*57:01 by DNA-PCR. Of the HLA-B17 positive samples, 31 (67.4%) were positive for HLA-B*57:01, 2 (3.25%) were positive for HLA-B*57:03, 11 (26.1%) were positive for HLA-B*58, and 2 (3.25%) were negative for both HLA-B*57 and HLA-B*58 antigens. The undetermined sample was negative for HLA-B*57 and HLA-B*58 alleles by DNA-PCR. CONCLUSIONS: This study shows that flow cytometry with mAb3E12 is a highly sensitive method (no false negatives) to implement prior to DNA-PCR analysis for rapid screening of HLA-B*57:01. Additional confirmation by molecular HLA typing method would be required in less than 10% of the cohort of HIV-1-infected individuals.

Kinetics of functionally distinct T-lymphocyte subsets in heart transplant recipients after induction therapy with anti-CD25 monoclonal antibodies.

T cells are involved in the maintenance of immunocompetence and in the development of alloimmune responses in solid organ transplant recipients. The kinetics of functionally distinct T-cell subsets in peripheral blood has received little attention in the field of heart transplantation. We performed a simultaneous analysis of the maturation, activation, and regulatory profiles of T cells using 4-color flow cytometry in a study of 77 heart recipients. Induction therapy included 2 doses of anti-CD25 monoclonal antibodies (daclizumab). Lymphocyte subsets were prospectively evaluated at different times before and up to 1 year after transplantation in 46 heart recipients. A separate cross-sectional study was performed in 33 heart recipients who had received a transplant more than 1 year previously to evaluate abnormalities persisting in the long term. As compared with baseline values, a decrease in regulatory CD4+ T-cell percentages (CD4+CD127lowCD25highFoxP3+) was observed from day 7 to 12 months after transplantation. Interestingly, T cells expressing the beta chain of IL-2 (CD122+) remained stable during the first 3 months. A significant decrease in the activation status of CD4 T cells was documented from day 7 to 1 year after transplantation, while the activation status of CD8+ T cells remained stable during follow-up. Compared with values for healthy controls (n=36), higher CD8+ terminally differentiated effector memory percentages (CD8+CD45RA+CCR7-) were observed from baseline up to more than 1 year after transplantation. Rejection was associated with higher levels of these cells during the first 6 months after transplant. We characterized the abnormalities in distinct functional T-cell subsets at different times before and after heart transplantation. Some of these abnormalities should be further investigated as biomarkers of clinical complications.

Outcomes of splenectomy in patients with common variable immunodeficiency (CVID): a survey of 45 patients.

Splenectomy has been used in patients with common variable immunodeficiency disorders (CVID), mainly in the context of refractory autoimmune cytopenia and suspected lymphoma, but there are understandable concerns about the potential of compounding an existing immunodeficiency. With increasing use of rituximab as an alternative treatment for refractory autoimmune cytopenia, the role of splenectomy in CVID needs to be re-examined. This retrospective study provides the largest cohesive data set to date describing the outcome of splenectomy in 45 CVID patients in the past 40 years. Splenectomy proved to be an effective long-term treatment in 75% of CVID patients with autoimmune cytopenia, even in some cases when rituximab had failed. Splenectomy does not worsen mortality in CVID and adequate immunoglobulin replacement therapy appears to play a protective role in overwhelming post-splenectomy infections. Future trials comparing the effectiveness and safety of rituximab and splenectomy are needed to provide clearer guidance on the second-line management of autoimmune cytopenia in CVID.

Evaluation of lymphoproliferative responses by carboxy fluorescein succinimidyl ester assay in heart recipients with infections.

The analysis of proliferative responses using 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) in flow cytometry is widely used to assess lymphocyte function. The aim of this study was to evaluate nonspecific and specific lymphoproliferative responses using CFSE in heart recipients before and after transplantation and their association with the development of infection. We used four-color flow cytometry to measure the response of peripheral CD3+, CD4+, and CD8+ T cells to phytohemagglutinin mitogen (PHA), tetanus toxoid, hepatitis B, and influenza vaccines using a CFSE proliferation assay in 12 heart recipients and 8 healthy control subjects. Recipients were prospectively evaluated. Immunological studies were performed before and at 3 months after transplantation. A 12-month clinical follow-up examination sought to detect the prevalence of severe infectious complications. Heart recipients (infected [n = 7] and uninfected [n = 5]) disclosed significantly lower percentages of proliferative responses than healthy controls against PHA at both study points. Baseline CD3+, CD4+, and CD8+, antitetanus proliferative responses were significantly lower in infected heart recipients than controls. Patients who developed infections displayed significantly lower percentages of CD3+CFSE and CD8+CFSE cells to PHA mitogen at 3 months after transplantation versus those without infections. In conclusion, nonspecific T-cell reactivity to PHA was lower in heart recipients with posttransplantation infections.

Decreased levels of serum complement C3 and natural killer cells add to the predictive value of total immunoglobulin G for severe infection in heart transplant recipients.

BACKGROUND: Infection remains a source of mortality in heart recipients. We previously reported that post-transplant immunoglobulin G (IgG) quantification can help identify the risk for infection. We assessed whether other standardized parameters of humoral and cellular immunity could prove useful when identifying patients at risk of infection. METHODS: We prospectively studied 133 heart recipients over a 12-month period. Forty-eight patients had at least one episode of severe infection. An event was defined as an infection requiring intravenous antimicrobial therapy. RESULTS: Cox regression analysis revealed an association between the risk of developing infection and the following: lower IgG2 subclass levels (day 7: relative hazard [RH] 1.71; day 30: RH 1.76), lower IgA levels (day 7: RH 1.61; day 30: RH 1.91), lower complement C3 values (day 7: RH 1.25), lower CD3 absolute counts (day 30: RH 1.10), lower absolute natural killer [NK] cell count (day 7: RH 1.24), and lower IgG concentrations (day 7: RH 1.31; day 30: RH 1.36). Cox regression bivariate analysis revealed that lower day 7 C3 levels, IgG2 concentration, and absolute NK cell count remained significant after adjustment for total IgG levels. CONCLUSIONS: Data suggest that early immune monitoring including C3, IgG2, and NK cell testing in addition to IgG concentrations is useful when attempting to identify the risk of infection in heart transplant recipients.

Restoration of humoral immunity after intravenous immunoglobulin replacement therapy in heart recipients with post-transplant antibody deficiency and severe infections.

IgG hypogammaglobulinemia is a risk factor for infection in heart recipients. We assessed reconstitution of humoral immunity after non-specific intravenous immunoglobulin (IVIg) replacement therapy administered to treat secondary IgG hypogammaglobulinemia in heart recipients with severe infections. The study population comprised 55 heart recipients who were administered IVIg (IVIg group) and 55 heart recipients with no severe infectious complications (control group). An event was defined as a severe infection requiring intravenous drug therapy during the first year after transplantation. The IVIg protocol comprised non-specific 5% pasteurized IVIg at a dose of 300-400 mg/kg/months. IgG titers were lower in the IVIg group than in controls at seven d (577 vs. 778 mg/dL, p < 0.001) and at one month (553 vs. 684, p = 0.003). After IVIg therapy, IgG concentrations were similar in both groups at three months (681 vs. 737, p = 0.25) and at six months (736 vs. 769, p = 0.46). At three months, the IVIg group had higher levels of antitetanus toxoid and anti-HBs (ELISA, 2.07 ± 2.11 vs. 0.60 ± 1.24 mg/dL [p = 0.003] and 42 ± 40 vs. 11 ± 31 IU/mL [p = 0.005], respectively) than controls. The mean number of infectious complications was significantly lower after IVIG therapy in the IVIG group. IVIg was associated with restoration of humoral immunity in heart recipients with post-transplant IgG hypogammaglobulinemia and severe infections.

Sublingual therapeutic immunization with a polyvalent bacterial preparation in patients with recurrent respiratory infections: immunomodulatory effect on antigen-specific memory CD4+ T cells and impact on clinical outcome.

Recurrent respiratory tract infections (RRTIs) are common clinical conditions in individuals with alterations of the immune function. A prospective open pilot study in a cohort of patients with RRTIs has been performed to assess whether sublingual immunization with a polyvalent bacterial vaccine could exert an immunomodulatory effect on the antigen-specific immunological responses and have an impact on the clinical outcome. Seventeen patients with RRTIs were recruited. An oral polyvalent bacterial preparation (Bactek®) was administered to all patients daily for 6 months. Immunological assessment was performed at baseline and at the end of immunization. Immunological measurements included: T cell-specific proliferations of CD3+CD4+ and CD3+CD8+ to Bactek® antigens, total immunoglobulin levels, antibodies to pneumococcal polysaccharide and tetanus toxoid and B, T and natural killer (NK) cell subsets. There was a significant increase in the proliferative capacity of CD3+CD4+ T cells specific to Bactek® antigens at month 6 in comparison to baseline (P < 0·0001). A significant increase in total CD3+ T cells was also observed (P < 0·05). No significant differences were observed between baseline and month 6 in levels of total immunoglobulins, specific antibodies and B, T or NK cell subsets. A significant reduction in the patient's rate of RRTIs was observed compared with 1 year prior to initiation of therapy (P < 0·0001). The results demonstrate that long-term administration of a sublingual polyvalent bacterial preparation in patients with RRTIs exerts an immune stimulating effect on CD4+ T helper cell responses to bacterial antigens which could be associated with clinical benefit.

Autonomic imbalance in celiac children.

AIM: Involvement of many organs and apparatus such as heart, central and peripheral nervous systems have been reported in celiac disease. Autonomic neuropathy has frequently been reported both in untreated and in gluten free diet (GFD) adult patients and, to our knowledge, has never been investigated in celiac children. The aim of the study was to evaluate autonomic function in children with celiac disease. METHODS: Fifteen children with untreated celiac disease were enrolled. Fifteen healthy children served as controls. None of the patients was diabetic. Central or peripheral neurological diseases, were absent. In all participants, at recruitment and after 24 months of GFD, serum anti-tTG and AEA levels, inflammatory markers, IgG, IgM and IgA anti-ganglioside antibodies, were performed. Heart rate variability indexes were employed to evaluate autonomic system balance. RESULTS: Our results indicate that also children with celiac disease may exhibit an imbalance of the neurovegetative system with a prevailing sympathetic tone, persisting on a GFD. All presented symptoms such as abdominal pain, diarrhea or constipation, vomiting, meteorism, regurgitation in whom autonomic dysfunction could be involved, but these symptoms disappeared on gluten free diet. This tend to exclude the prevailing sympathetic tone as a main factor underlying symptoms of celiac disease. CONCLUSION: Children affected by celiac disease exhibit an enhanced sympathetic tone, persisting after 24 months of GFD whereas gastrointestinal and systemic symptoms disappear. The pathogenesis of this phenomenon still remains unclear.