Response to varicella immunization in pediatric liver transplant recipients

BACKGROUND

Individuals undergoing therapeutic immunosuppression are at risk of severe varicella-zoster virus (VZV) infection, particularly those without evidence of previous infection.

METHODS

Eleven children, median age 10 months (range 5.5 months to 7 years and 9 months) received one dose of varicella vaccine (Varilrix, SmithKline Beecham plc, UK) before liver transplantation (median interval 95 days, range 40-289 days). The serological response to varicella vaccine was evaluated retrospectively and matched with the outcome and management of any subsequent exposures to VZV.

RESULTS

Three children responded postimmunization, six children showed no response, and in two children the outcome was difficult to interpret having received blood products. Four children required varicella-zoster immunoglobulin prophylaxis posttransplantation, two of whom developed mild chickenpox.

CONCLUSIONS

Only 3 of 11 children developed a clear antibody response to varicella vaccine. Administration of varicella vaccine did not affect the management of subsequent VZV exposures.

Intranasal immunization with mumps virus DNA vaccine delivered by influenza virosomes elicits mucosal and systemic immunity

To improve the efficiency of liposome-mediated DNA transfer as a tool for gene therapy or vaccinology, we have further developed a new delivery system based on the modified immunopotentiating reconstituted influenza virus (IRIV). In this study, we engineered a plasmid DNA vector expressing the mumps virus hemagglutinin or the fusion protein. The administration of this DNA vaccine delivered by influenza virosomes, in combination with the mucosal adjuvant Escheriagen via the intranasal route, was efficient for inducing an immune response, both mucosally and systemically, in mice. The production of IgG2a mumps virus-specific antibodies and the secretion of interleukin 10 (IL-10) by antigen-specific T cells indicated that not only Th1 but also Th2 responses were induced by this DNA vaccine formulation. These results suggest that cationic virosomes in combination with Escheriagen may have great potential as an efficient delivery system for intranasal DNA immunization and provide an immune barrier at the mucosal sites.

[Inguinal hernioplasty with calibrated prosthesis (personal modification of the Trabucco technique]

From January 1994 to December 1997, the authors operated on 636 patients with primary inguinal hernia, using an original modification of Trabucco's tension-free and sutureless technique. The hernial defect is sized according to Gilbert's classification modified by Rutkow and Robbins and repaired with one or more plugs (up to four in the authors' experience) in relation to its extent. The posterior wall is reconstructed over the plugs encompassing the transversalis fascia and a wing of the plug superiorly and the iliopubic tract inferiorly. The double-layer polypropylene mesh is fashioned intraoperatively and the key-hole tailored to the variable distance between the spermatic cord and the pubic tubercle. All patients ambulated immediately after the operation, had a light meal two hours later and were discharged within one day of surgery. During a 3 months to 4 year follow-up only one recurrence has been recorded (0.16%). The proposed technique allows to perform a repair to measure ("calibrated") with minimal pain, immediate rehabilitation and early return to unrestricted activity.

Long-term survival of ex-thalassemic patients with persistent mixed chimerism after bone marrow transplantation

Twenty-six transplanted thalassemic patients out of 295 analyzed, showed the presence of persistent mixed chimerism, over a period of time varying between 2 and 11 years after BMT. Despite the presence of large numbers of residual host cells, these transplanted thalassemic patients no longer require red blood cell transfusions and have a functional graft, producing sufficient levels of hemoglobin A ranging from 8.3-14.7 g/dl. These ex-thalassemic patients with persistent mixed chimerism, although they did not achieve complete donor engraftment are no longer exposed to the risk of graft rejection. The mechanisms underlying this apparent state of tolerance or education in these patients are at the present time unknown. However, these observations may be useful for physicians involved in defining optimal strategies for clinical gene therapy, in utero hematopoietic stem cell transplantation and adoption of less toxic conditioning regimens in mini-transplantation.

Bone marrow transplantation from alternative donors for thalassemia: HLA-phenotypically identical relative and HLA-nonidentical sibling or parent transplants

Twenty-nine patients with thalassemia and a median age of 6 years (range 1.1-33 years) were given a BMT from an alternative donor. Six of the 29 donors were HLA-phenotypically identical and two were mismatched relatives, 13 were mismatched siblings and eight were mismatched parents. Six patients received no antigen (relatives), 15 patients one antigen, five patients two antigen and three patients three antigen disparate grafts. Twenty-three patients were in class 2 or class 3, whereas six patients were in class 1. Thirteen patients were given BUCY, nine patients BUCY plus ALG, six patients BUCY plus TBI or TLI and one patient BUCY with prior cytoreductive-immunosuppressive treatment as conditioning. As GVHD prophylaxis four patients received MTX, 22 CsA + MTX + methylprednisolone (MP) and three patients CsA + MP. Thirteen of 29 patients (44.8%) had sustained engraftment. The probability of graft failure or rejection was 55%. There were no significant differences between antigen disparities and graft failure. The incidence of grade II-IV acute GVHD was 47.3% and chronic GVHD was 37.5%. The incidence of acute GVHD was higher in patients receiving one or two antigen disparate in the GVHD direction grafts (vs no antigen) (P EQ 0.04; odds ratio 10.8; 95% CI 1.5-115). The probability of overall and event-free survival was 65% and 21%, respectively, with median follow-up of 7.5 years (range 0.6-17 years) for surviving patients. The degree of HLA disparity between patient and donor did not have a significant effect on survival. The incidence of nonhematologic toxicity was low. Transplant-related mortality was 34%. GVHD (acute or chronic) was a major contributing cause of death (50%) followed by infections (30%). We conclude that at present, due to high graft failure and GVHD rates, BMT from alternative donors should be restricted to patients who have poor life expectancies because they cannot receive adequate conventional treatment or because of alloimmunization to minor blood antigens.

[Hernia repair with local anesthesia]

The authors report the results of their own personal experience with inguinal and femoral hernioplasties (424 cases) performed under loco-regional anaesthesia. This anaesthetic approach together with the use of prosthetic techniques (tension-free and suture-less) represent the "Gold Standard" in the surgical treatment of hernia. The absence of mortality, the remarkable reduction in terms of postoperative complications, days of hospitalization (one day surgery) represent outstanding advantages. The cooperation of the patient and the stress test at the end of the operation are further advantages of the proposed technique.

Comparative in-vitro activity of moxifloxacin, minocycline and azithromycin against Chlamydia spp

The in-vitro activity of moxifloxacin, a new 8-methoxyquinolone, was compared with minocycline and azithromycin against 40 strains of Chlamydia trachomatis, Chlamydia pneumoniae and Chlamydia psittaci. Both the MIC and the MBC of moxifloxacin ranged from 0.03 to 0.125 mg/L. MICs of minocycline ranged from 0.015 to 0.06 mg/L and MBCs between 0.03 and 0.25 mg/L. MICs of azithromycin ranged from 0.03 to 0.125 mg/L and the MBCs between 0.06 and 0.5 mg/L. MBC values of moxifloxacin were the same as MICs in 32 (80%) of 40 strains tested, whereas those of minocycline and azithromycin were two to four times higher than their MICs. These data confirm those previously obtained indicating that quinolones kill chlamydial strains at concentrations equivalent to their MICs.

PCR-based restriction pattern typing of the vacA gene provides evidence for a homogeneous group among Helicobacter pylori strains associated with peptic ulcer disease

The results of PCR-based molecular typing of Helicobacter pylori strains by restriction fragment length polymorphism analysis of a 1, 161-bp nucleotide sequence of the midregion of the vacA gene are reported. A total of 48 H. pylori strains isolated from gastric biopsy specimens obtained from 18 patients with peptic ulcer dyspepsia, 15 patients with nonulcer dyspepsia, and 15 asymptomatic H. pylori-infected subjects were studied. Highly heterogeneous restriction patterns were obtained by digestion of PCR products with SauII, BglII, and HhaI, whereas HaeIII digestion resulted in a strictly homogeneous profile for H. pylori strains isolated from 14 of 18 (77.7%) patients with peptic ulcer dyspepsia, but a strictly homogeneous profile was found for strains from only 8 of 15 (53.3%) patients with nonulcer dyspepsia (P = 0.163) and 5 of 15 (33.3%) asymptomatic H. pylori-infected subjects (P = 0.014). A potentially important aspect of the results obtained is the clinical relevance, since a single restriction pattern seems to be able to identify the majority of H. pylori strains associated with peptic ulcer disease.

[Organizational and surgical-technical aspects of the service of abdominal hernioplasty]

The authors guided by the experience matured from 1/01/94 to 30/06/97 (435 abdominal hernioplasties performed, mainly inguinal and femoral) illustrate the organizational formalities and the technical aspects of a Hernia Surgery Service. In particular, they highlight the advantages of the routine use of local anaesthesia and of tension-free techniques, carried out on a day surgery rule (immediate rehabilitation, greater facilitation to elective surgery, access to the elderly at high anaesthetic risk). Eventually, they emphasize the remarkable reduction of sanitary costs and the outstanding social, practical and didactic value of such Hernia Centers.

[AIDS-related cryptococcosis: diagnostic aspects, prognostic and therapeutic implications]

Diagnostic techniques of AIDS-related cryptococcosis were assessed in a series of 43 HIV-infected patients, and microbiological features were correlated to the clinical course and outcome of disease. Polysaccharide antigen detection was the most sensitive method for central nervous system infection, followed by direct microscopy and culture: in 4 patients this visceral mycosis was initially diagnosed by the detection of isolated cerebrospinal fluid antigen. Thirty-one patients out of 43 suffered from disseminated infection (with positive blood cultures and/or antigenemia). The occurrence of clinical relapses, a lethal outcome, and time to relapses or to death, did not differ significantly between patients with isolated central nervous system and those with disseminated cryptococcosis.

Characteristics of non-O1 Vibrio cholerae isolated from the effluents of a treatment plant

We report the results of a study concerning the characteristics of 19 Non-O1 Vibrio cholerae strains isolated from the incoming sewage and the effluents of the treatment plant in Bologna (Italy). These strains were compared to those of a strain of Vibrio cholerae biotype El Tor. The behaviour of the Non-O1 Vibrios was seen to be quite similar to those of the El Tor biotype in all aspects studied and antigenic correlations were found by means of immunoblotting and cytotoxin production on VERO cells. Since these bacterial strains may be pathogenic in humans, we believe it useful to describe some of their characteristics.

Detection of serum antibodies to CagA and VacA and of serum neutralizing activity for vacuolating cytotoxin in patients with Helicobacter pylori-induced gastritis

Thirty patients with dyspepsia, with histological diagnosis of gastritis, and with endoscopic diagnosis of peptic ulcer disease (PUD) (n = 13) or nonulcer dyspepsia (NUD) (n = 17) were admitted to the study. Helicobacter pylori vacuolating cytotoxin-producing strains (Tox+) were isolated from 14 (46.7%) patients, whereas non-cytotoxin-producing (Tox-) H. pylori strains were isolated from the remaining patients. Of 30 patients studied, 20 (66.7%) had serum cytotoxin neutralizing activity in vitro. Fourteen patients with Tox+ H. pylori strains showed serum cytotoxin neutralizing activity and serum immunoglobulin G (IgG) and IgA antibodies reactive with both 87-kDa H. pylori vacuolating cytotoxin (VacA) and 128-kDa cytotoxin-associated gene product (CagA) by immunoblotting using native enriched preparations of VacA and CagA proteins from H. pylori culture supernatants as the antigens. A 94-kDa antigen cross-reacting with the 87-kDa VacA protein could be demonstrated in culture supernatant with immune sera from humans and animals. All patients (n = 10) lacking serum neutralizing activity were also negative for IgG or IgA against VacA antigen, whereas 6 of the 10 patients showed IgG serum antibody responses against CagA antigen. The prevalence of antibodies to VacA and CagA antigens was significantly (P < 0.001) higher in patients with gastritis (20 and 26 patients for VacA and CagA, respectively, of 30 patients) than in H. pylori culture-negative controls (0 of 27 for both VacA and CagA) and in randomly selected blood donors (17 and 21 for VacA and CagA, respectively, of 120 subjects). All patients with PUD had antibodies to CagA, whereas 13 of 17 (76.5%) patients with NUD had anti-CagA antibodies. Serum IgG antibodies to VacA were present in 9 (69.2%) patients with PUD of 13 patients and in 11 (64.7%) patients with NUD of 17 patients. Anti-CagA antibodies seemed to correlate better with PUD than anti-VacA antibodies.

Characterization of a new isolate of Chlamydia trachomatis which lacks the common plasmid and has properties of biovar trachoma

A Chlamydia trachomatis urethral isolate, alpha/95, yielding pgp3-negative but otherwise normal inclusions by immunofluorescence also gave negative results when pCT-homologous DNA was searched by PCR and Southern blotting. omp-1 sequence analysis identified alpha/95 as a new genotype B variant. These findings confirm that pCT is not required for chlamydial growth in vitro.

Value of serology (ELISA) for the diagnosis of Helicobacter pylori infection: evaluation in patients attending endoscopy and in those with fundic atrophic gastritis

In the present study we assessed the diagnostic accuracy of four commercial IgG enzyme-linked immunosorbent assay (ELISA) kits (Autoplate, H.pylori-EIA-Well, Enzygnost, Helori-test) and evaluated the performance of these tests in patients with fundic atrophic gastritis. Serum antibodies to Helicobacter pylori were measured in 70 out-patients attending endoscopy for dyspepsia and 43 patients with non-autoimmune fundic atrophic gastritis. Using the cut-off values recommended by the manufacturers, and comparing serological findings with gastric biopsy results of dyspeptic out-patients attending endoscopy, the four kits showed a sensitivity and specificity, respectively, of 91% and 96%, for Autoplate, 67% and 100% for H.pylori-EIA-Well, 79% and 100% for Enzygnost, and 81% and 96% for Helori-test. Evaluation in patients with atrophic gastritis revealed a high prevalence of antibodies to Helicobacter pylori (84%) and it demonstrated that patients with and those without gastric colonization by this microorganism had a similar rate of seropositivity (76-84% vs 50-78%). In conclusion, our data demonstrate that: a) this assay is a reliable and valid method to detect gastric colonization by Helicobacter pylori; b) positive serum antibody associated with a negative detection of Helicobacter pylori in the gastric mucosa suggests mucosal atrophy; c) patients with fundic atrophic gastritis should be excluded from studies investigating the value of serology in diagnosing Helicobacter pylori infection.

Detection of serum antibodies against Chlamydia pneumoniae by in vitro neutralization and microimmunofluorescence assays

Antibodies to Chlamydia pneumoniae (IOL-207) were studied by the microimmunofluorescence (MIF) assay and in vitro neutralization in serum samples from 230 healthy adults and 332 patients at risk of C. pneumoniae infection. In the MIF test, the prevalence of immunoglobulin G (IgG) antibody was 53.9% among healthy subjects and 40.7% in the patients. An MIF antibody titre of > or = 1 : 512, consistent with acute infection by C. pneumoniae was documented in 23 out of 332 patients, and in none of the healthy adults. C. pneumoniae complement-dependent neutralizing antibody was detected in 25.8% and 31.2%, respectively of MIF-positive sera from healthy subjects and patients. The neutralizing antibody detection rate was 52.2% among the 23 patients with MIF titres of > or = 1 : 512. Complement-independent neutralization was observed in only 5 sera from healthy subjects and in 3 sera from patients. The complement-dependent neutralizing ability of sera significantly (p < 0.001) correlated with MIF titres.

Detection of Chlamydia trachomatis by a ligase chain reaction amplification method

BACKGROUND AND OBJECTIVES

The ligase chain reaction is an in vitro DNA amplification technique that exponentially amplifies selected DNA sequences.

GOAL

To evaluate a ligase chain reaction assay for the detection of Chlamydia trachomatis cryptic plasmid DNA (LCx Chlamydia) in patients routinely attending a sexually transmitted disease center in Italy.

STUDY DESIGN

Urethral or cervical swabs were obtained from 501 consecutive patients (334 men and 167 women). The samples were assayed in parallel with LCx Chlamydia and conventional tissue culture; discordant results were further assayed by direct immunofluorescence and a ligase chain reaction with alternate primers.

RESULTS

After resolution of discordant results, the LCx method showed a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 99.3%, 96.7%, and 100% in men; 100%, 100%, 100%, and 100% in women; and 100%, 99.5%, 97.1%, and 100% overall, respectively. By comparison, the sensitivity of tissue culture was 81.4% in men, 50% in women, and 77.6% overall.

CONCLUSIONS

The automated LCx method is sensitive, fast, and accurate and represents a useful diagnostic tool for C. trachomatis infection, even in low and medium prevalence populations.

Differences in the envelope proteins of Chlamydia pneumoniae, Chlamydia trachomatis, and Chlamydia psittaci shown by two-dimensional gel electrophoresis

Analysis by two-dimensional gel electrophoresis of the N-laurylsarkosinate(Sarkosyl)-insoluble envelope complexes of L-[35]S-cysteine-labeled elementary bodies of Chlamydia pneumoniae strain IOL-207, Chlamydia trachomatis serovar LGV2, D, and F, and Chlamydia psittaci strain 6BC showed differences in the molecular charges of chlamydial outer membrane proteins. The apparent isoelectric point (pI) of the major outer membrane protein of C. pneumoniae strain IOL-207 was 6.4, whereas the pI of the major outer membrane protein of the C. trachomatis and C. psittaci strains differed little from one another, ranging from 5.3 to 5.5. The 60-kDa cysteine-rich protein of C. pneumoniae was the only 60-kDa chlamydial protein with a pI value (5.9) more acidic than that of the corresponding major outer membrane protein. As a general rule, the charges of both the 60-kDa and the low-molecular-mass (12-15 kDa) cysteine-rich proteins were widely variable, depending on the strain. However, in each individual strain, the variation of the charge of the 60-kDa protein had a compensatory change in the low-molecular-mass cysteine-rich protein.