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C Merlino

Publications and source records attributed to C Merlino.

At least 37 records · Page 2Linked to original sources
PubMed1986

[Effect of mercaptans on serum IgA].

Using reducing agents like dithiothreitol (DTT) 2.5 mM IgM lose their ability to bind antigens but they can be still detected by an anti-IgM antiserum. IgA are more resistant to reduction than IgM but using higher concentrations of DTT they lose both the ability to bind antigens and the possibility to be detected by an anti-IgA antiserum. Because of this fact IgA after mild reduction can result more or less inactivated according to the method employed to detect them. Using ELISA or similar methods that need an immunological detection of preformed immune complexes IgA-Ag, the loss of activity is more marked than using techniques such as HAI that detect them directly.

Antigen-Antibody Reactions↗
PubMed1985

Virus-specific polymeric immunoglobulin A antibodies in serum from patients with rubella, measles, varicella, and herpes zoster virus infections.

More than 85% of the immunoglobulin A (IgA) antibodies in normal adult serum are monomeric (m-IgA). By contrast, virus-specific IgA is mainly polymeric (p-IgA) in sera from patients with rubella, measles, and varicella. Specific m-IgA antibodies only reach quantitative significance in late convalescence. In patients with herpes zoster, on the other hand, a varying response was observed: in three of six sera, specific IgA was absent or at a very low titer, whereas in the remaining three cases, a high titer of both p-IgA and m-IgA was noted. These results suggest that in the initial response to rubella, measles, and varicella-zoster viruses, specific IgA first appears as p-IgA and only later becomes, or is replaced by, m-IgA.

Antibodies, Viral↗
PubMed1983

Separation of IgM for diagnostic purposes by exclusion chromatography: a comparison between six gels.

Sera from rubella patients were fractionated with six different gels on a 0.9 X 30 cm column. Fractionation efficiency was evaluated by determining the IgM, IgA and IgG concentrations in each fraction and titring the rubella virus hemagglutination-inhibiting antibodies before and after treatment with 2-mercaptoethanol. All six gels were able to separate IgM from the other Ig, but the distance between their elution peaks varied considerably. Assessment of the usefulness of a gel for diagnostic purposes requires evaluation of its ability to separate IgM from the oligometric IgA often present in sera and a possible source of diagnostic error. Ultrogel AcA 22 and Bio-Gel A5m gave the best results. In addition to displaying good peak separation, they eluted IgM within their linear fractionation range.

Adult↗
PubMedDate not supplied

[Polyomavirus BK nephropathy in renal transplant: 2 cases with different clinical expressions and review of the literature].

INTRODUCTION: Polyomavirus BK nephropathy is emerging as a significant cause of interstitial nephritis and allograft dysfunction (1-2). CASE REPORT: Two patients with renal transplants from cadaveric kidneys were treated with Tacrolimus plus Mycophenolate Mofetil (MMF) and Cyclosporine plus MMF, respectively. Their renal function gradually deteriorated eight to twelve months after the transplant. The renal biopsy of the first patient showed signs of significant interstitial tubulite, which necessitated the anti-rejection therapy with intravenous steroid pulses. After the pulses there was an additional dramatic increase in plasmatic creatinine, which suggested a revaluation of the kidney biopsy because of suspected Polyomavirus BK (BKV) nephropathy. In fact, after a more careful review, the suspicion of BKV infection was confirmed by the presence of intranuclear inclusions of tubular epithelium cells and marked denudation of the tubular basal membrane. The subsequent screening in both cases confirmed the presence of decoy cells in the urine, while the immunohistochemical analysis of the renal biopsy was strongly positive for the SV40 antigen. Our diagnosis was that of interstitial nephritis due to Polyomavirus BK that, in the first patient, was expressed by more aggressive clinical progress, probably due to enhanced immunosuppression from incorrect diagnosis of the interstitial rejection. The pre-transplant clinical outcome of the first patient was characterised by proteinuric nephropathy without any histological confirmation. Furthermore, we observed abundant pre-transplant residual diuresis and glucose intolerance. All these elements led us to hypothesise that native kidneys could have a fundamental role as viral reservoirs. CONCLUSION: Even though we reconfirm the decisive role of the immunosuppressive therapy and of the donor s kidney as the fundamental causes of Polyomavirus reactivation, we believe that it cannot be the result of a possible active role by the native kidney. In fact, as already noted, the SV40 genome is important in the pathogenesis of focal gomerulosclerosis. Furthermore, reports of polyoma nephropathy in not-yet-transplanted patients could accredit the role of the native kidneys as important viral reservoirs capable of inducing nephropathy in renal transplant patients.

Adult↗
PubMedDate not supplied

[Epstein Barr viral load monitoring in mononuclear lymphocytes and serum of renal transplant recipients using a quantitative PCR protocol].

BACKGROUND: Post-transplant lymphoproliferative disorders (PTLD), ranging from lymphoid hyperplasia to clonal malignancy, are severe complications arising in solid organ transplant patients; their reported incidence ranges from 1 to 20%, according to factors such as type of transplanted organ and age of recipients. A strong correlation between Epstein-Barrvirus (EBV) infection, the grade and type of immunosuppression and the development of PTLD has been recognized. The detection and quantification of EBV-DNA load in peripheral blood have been utilized as prognostic markers for the development of PTLD, showing a correlation between high levels of EBV-DNA in the blood and the development of PTLD. In this study, we monthly monitored EBV viral load in 15 renal transplant recipients for six months. The number of EBV-DNA copies was measured in peripheral blood mononuclear cells (PBMC) and serum samples by a quantitative PCR protocol developed in our laboratory. METHODS: Our EBV-DNA quantification protocol employs a previous screening of samples containing a significant number of viral DNA copies (>=1000 copies/105 PBMC or 100 mL serum) by semi-quantitative PCR followed by a precise quantification of the only significant samples by quantitative-competitive (QC)-PCR. RESULTS: Our 15 renal transplant patients neither developed PTLD nor had recurrent acute illnesses or acute graft rejections during the study. The results obtained in the monthly follow up of EB viral load in PBMC samples confirmed its fluctuation in asymptomatic patients reported in the literature. In particular, 5/14 (35.7%) of EBV seropositive patients had an EBV-DNA load equal to 1000 EBV copies /105 PBMC, and 1/14 (7.1%) reached 5000 EBV copies /105 PBMC at least once in our study. In the EBV seronegative patient, EBV-DNA in PBMC samples was always undetectable (less than 100 DNA copies/105 PBMC). EBV-DNA load in all serum samples was less than threshold value of our quantification protocol (<100 DNA copies/100 mL serum). With regard to the immunosuppressive treatment, it should be noted that 66.7% of the six patients in whom EBV load reached values equal to or higher than 1000 DNA copies/105 PBMC, were on FK506 whereas only 33.3% of them were on CyA. CONCLUSIONS: Since the high positive predictive value of EB viral load in peripheral blood for diagnosis of PTLD reported by several Authors, and the described absence of correlation between the serological evidence of EBV reactivation and EB viral load, EBV viral load measurement in PBMC and serum samples using quantitative PCR techniques is a powerful diagnostic tool to monitor transplanted patients at risk of developing PTLD.

Cyclosporine↗
PubMedDate not supplied

[Epstein-Barr virus infection and immunoglobulin abnormalities in renal transplant recipients].

The relationship between immunoglobulin abnormalities and EBV infection has been investigated in 65 renal transplant patients. Immunoglobulins abnormalities were demonstrated in 44 (68%) patients, 8 of them (18%, 12% of all patients) had a monoclonal component. Up to now no lymphoproliferative disorder has been observed in these patients. All patients were EBV seropositive at the beginning of the study and in 22 of them (33%) a reactivation of EBV infection could be demonstrated. No relation has been observed between immunoglobulin abnormalities, EBV reactivation, age or sex. By contrast, a significant relation was found between EBV reactivation and immunosuppressive treatment: patients under triple therapy with Azathioprine, Cyclosporine A and Prednisone had less EBV reactivation compared to those under Cyclosporine A treatment.

Adolescent↗
PubMedDate not supplied

[Infection by human herpesvirus type 6 (HHV-6) and renal transplantation].

Human herpes virus type 6 (HHV-6) infection was serologically investigated in renal transplant recipients. Before transplantation, 75.5% of patients was seropositive for HHV-6 and no correlation with age, sex and time on dialysis was found. During the first month after transplantation 66% of patients showed a variation in serological status against HHV-6 (seroconversion or fourfold increase of antibody titer). All patients who seroconverted had received the kidney from a HHV-6 seropositive donor, furthermore, in 11/13 (84.6%) pairs of patients receiving the kidney form the same seropositive donor, both members or had HHV-6 active infection or had no infection. The frequency of HHV-6 active infection in seropositive patients is almost the same in case of seronegative or seropositive donor. Comparing HHV-6 and CMV infections, they resulted independent as CMV infection in these patients occurs in a following period (II-III month). Notwithstanding a higher frequency of kidney rejection in patients with active HHV-6 infection, no significative correlation was found.

Adult↗
PubMedDate not supplied

[Anti-CMV antibody affinity in renal transplant recipients].

Variations in anti-CMV antibody affinity have been studied in 106 renal transplant patients. Maturation of immune response has been followed during two years after transplantation evaluating antibody affinity by ELISA before and after urea denaturation treatment. In primary infections while the antibody titer rises, the resistance to denaturing treatment rises as well, indicating an increased antibody affinity. In patients already seropositive at transplantation, the increase of antibody affinity has also been found: comparing the affinity index (AI) at transplantation and one year later, only 16.5% of patients showed an AI value between 80 and 100 at transplantation, whereas after one year 62.3% of patients reached such AI values (p = 0.0001).

Antibodies, Viral↗
PubMedDate not supplied

CMV-specific polymeric and monomeric IgA antibodies in serum of renal transplant patients.

CMV-specific IgA, IgM and IgG antibodies were detected by ELISA in sera from 81 renal transplant patients. Twenty-seven patients were followed from transplantation; 6 patients who underwent on transplantation before the beginning of the study were followed during admissions for graft failure or acute illness; 48 outpatients were periodically monitored. One of the patient followed from transplantation experienced a primary CMV infection, serologically demonstrated by the appearance of specific IgM and IgG. Specific IgA appeared at the same time as IgM and lasted for about six months. A specific IgA response was observed in all but five recurrent CMV infections too, even when specific IgM were not present. In all outpatients periodically monitored for CMV serology specific IgA were not found. About specific IgA polimerization, a transient marked polymeric IgA (p-IgA) response was observed in only the primary infection whereas in all the other IgA positive patients, specific IgA were represented by monomers (m-IgA).

Adult↗
PubMedDate not supplied

Replication of HHV-6 in cord blood lymphocytes and Jurkat cells.

Replication of HHV-6 in cord blood lymphocytes (CBL) and Jurkat cells has been studied by comparing their infection rate and susceptibility. Jurkat cells were less susceptible to HHV-6 infection and CBL cell cultures stimulated with PHA proved more sensitive culture for its isolation.

Antibodies, Monoclonal↗
PubMedDate not supplied

[Serologic follow-up of cytomegalovirus, herpes simplex and varicella-zoster infections in kidney transplant recipients].

In the present paper the characteristics of cytomegalovirus (CMV), herpes simplex virus (HSV) and varicella-zoster virus (VZV) infections were serologically investigated in renal transplant recipients. At transplantation CMV-seropositivity was 88.2%. At the end of the study, the frequency of primary CMV-infections was 58.3% and the frequency of recurrent infections (reinfections or reactivations) was 84.4%. The 57.1% of primary infections and the 64.5% of recurrent infections occurred between the first and the third month after transplantation. There was no correlation between recurrent infections and type of immunosuppressive treatment (CyA vs. Triple). The 70% of pairs of patients who received a kidney from the same CMV-seropositive donor reacted in the same way: or neither had any infection or both had active CMV-infection. There was no correlation between rejection and active CMV-infection. HSV-seropositivity was 96.2%. Primary HSV-infections didn't occur and the frequency of reactivation in seropositive patients was 31.4%. No correlation was found between rejection and active HSV-infection as well. As regards VZV-infection, seropositivity at transplantation was 90%. Primary VZV-infections didn't occur. During the study, seropositive patients showed variations in VZV-antibody titers which returned to initial values. Clinical signs of zoster were observed in 6% of patients at third and ninth month after transplantation and were serologically confirmed.

Adolescent↗
PubMedDate not supplied

Low prevalence of HTLV-I infection in drug addicts in Turin.

Anti-HTLV-I antibody presence in drug addicts dead in 1987-1988 in Turin, was evaluated. Comparing the prevalence of HTLV-I infection with that of HIV and HBV infections, a different way and/or rate of spread of HTLV-I infection is suggested.

Female↗
PubMedDate not supplied

Anti-HBc polymeric IgA antibodies in serum from acute hepatitis B patients.

Serum anti-HBc IgA antibodies can be demonstrated in acute hepatitis B patients. At first, they are mainly polymeric (p-IgA), whereas monomeric IgA (m-IgA) become detectable 3 months later. In most cases, anti-HBc IgA cannot be demonstrated after 6-12 months. From a diagnostic point of view, specific p-IgA can be regarded as a marker of active infection but, compared to IgM, their demonstration is more difficult.

Acute Disease↗
PubMedDate not supplied

[Specific IgA in the serological diagnosis of viral infections].

In acute viral infections, specific IgM antibodies appear early and persist for a short period of time; by contrast IgG antibodies persist longer. The diagnostic significance of specific serum IgA is still discussed. We observed that in acute systemic infections, serum IgA appear early and are mainly polymeric (p-IgA) whereas monomers (m-IgA) appear in late convalescence. On the other hand, in secondary infections or in reinfections these immunoglobulins are mainly represented by monomers. In mucosa confined infections, serum IgA are almost absent suggesting that their synthesis is not related to mucosal stimulation.

Antibodies, Viral↗
PubMedDate not supplied

Anti-HIV and anti-HBc antibodies and HBsAg in postmortem blood of drug addicts: the picture for 1988.

Serological markers of HIV and HBV infections were studied in 90 drug addicts who died in 1988 and were medicolegally autopsied at the Institute of Forensic Sciences, University of Turin. Nineteen (21.1%) displayed evidence of HIV infection, demonstrated by the presence of anti-HIV antibodies; fifty-nine (65.5%) HBV infection, demonstrated by the presence of anti-HBc antibodies and/or HBsAg; nine (10%) had HBsAg, indicating potential infectiousness for HBV infection.

Adolescent↗
PubMedDate not supplied

Anti-HIV antibodies in postmortem vitreous humor.

Anti-HIV antibodies were detected in postmortem blood and vitreous humor samples from 60 drug addicts died in 1988 and medicolegally autopsied at the University Institute of Forensic Science of Turin. Fifteen subjects were positive both in blood and in vitreous samples confirming the possibility to detect anti-HIV antibodies in vitreous humor in the screening of high-risk population.

Autopsy↗
PubMedDate not supplied

[Specific IgG for viral capsid antigen (VCA) of Epstein-Barr virus: evaluation of several commercial kits].

Four methods to detect IgG antibodies to Epstein-Barr virus in serum samples of aspirate in renal transplant patients were evaluated. Further to technical characteristics, the assays were compared as to sensitivity, specificity and positive and negative predictive value. 100% of specificity was found for all methods whereas sensibility and negative predictive value were different among the different methods.

Antigens, Viral↗