Immunogenicity of meningococcal polysaccharide ACWY vaccine in primary immunized or revaccinated adults

Meningococcal polysaccharide (Men-Ps) vaccine immunogenicity following either primary immunization or revaccination in adults was evaluated. The study population consisted of subjects who have received tetravalent Men-Ps vaccine once (group 1) or at least twice, with a 2-6 dose range (group 2). Human leucocyte antigen (HLA)-typing was performed by polymerase chain reaction and specific immunoglobulin (Ig)G was measured by enzyme-linked immunosorbent assay. Nine months post-immunization, the percentages of individuals with levels of anti-Men-Ps IgG ≥ 2 µg/ml were comparable in both groups, with the exception of anti-Men-PsW₁₃₅ IgG, which were significantly higher in group 2. The percentage of subjects doubling IgG levels at 9 months was significantly higher in group 1. The high baseline anti-Men-Ps antibody levels negatively influenced the response to revaccination, suggesting a feedback control of specific IgG. The calculated durability of anti-Men-Ps IgG was 2·5-4·5 years, depending on the Men-Ps, following a single vaccine dose. No interference by other vaccinations nor HLA alleles association with immune response were observed. This study confirms that Men-Ps vaccine in adults is immunogenic, even when administered repeatedly, and underlines the vaccine suitability for large-scale adult immunization programmes that the higher costs of conjugate vaccines may limit in developing countries.

Safety and immunogenicity of co-administered MF59-adjuvanted 2009 pandemic and plain 2009-10 seasonal influenza vaccines in rheumatoid arthritis patients on biologicals

Rheumatoid arthritis (RA) patients under immunosuppressive therapy are particularly susceptible to infections, mainly of the respiratory tract, thus vaccination may represent a strategy to reduce their incidence in this vulnerable population. In the 2009-10 influenza season, the safety and immunogenicity of co-administered non-adjuvanted seasonal and MF59-adjuvanted pandemic influenza vaccines were evaluated in this study in 30 RA patients under therapy with anti-tumour necrosis factor (TNF)-α agents or Abatacept and in 13 healthy controls (HC). Patients and HC underwent clinical and laboratory evaluation before (T0), 1 (T1) and 6 months (T2) after vaccinations. No severe adverse reactions, but a significant increase in total mild side effects in patients versus HC were observed. Both influenza vaccines fulfilled the three criteria of the Committee for Proprietary Medicinal Products (CPMP). Seroconversion rate for any viral strain in patients and HC was, respectively, 68 versus 45 for H1-A/Brisbane/59/07, 72 versus 81 for H3-A/Brisbane/10/07, 68 versus 54 for B/Brisbane/60/08 and 81 versus 54 for A/California/7/2009. A slight increase in activated interferon (IFN)-γ-, TNF-α- or interleukin (IL)-17A-secreting T cells at T1 compared to T0, followed by a reduction at T2 in both patients and HC, was registered. In conclusion, simultaneous administration of adjuvanted pandemic and non-adjuvanted seasonal influenza vaccines is safe and highly immunogenic. The largely overlapping results between patients and HC, in terms of antibody response and cytokine-producing T cells, may represent further evidence for vaccine safety and immunogenicity in RA patients on biologicals.

A case of dengue type 3 virus infection imported from Africa to Italy, October 2009

In October 2009, a traveller returning from Africa to Italy was hospitalised with symptoms suggestive of a haemorrhagic fever of unknown origin. The patient was immediately placed in a special biocontainment unit until laboratory investigations confirmed the infection to be caused by a dengue serotype 3 virus. This case reasserts the importance of returning travellers as sentinels of unknown outbreaks occurring in other countries, and highlights how the initial symptoms of dengue fever resemble those of other haemorrhagic fevers, hence the importance of prompt isolation of patients until a final diagnosis is reached.

A case of dengue type 3 virus infection imported from Africa to Italy, October 2009

In October 2009, a traveller returning from Africa to Italy was hospitalised with symptoms suggestive of a haemorrhagic fever of unknown origin. The patient was immediately placed in a special biocontainment unit until laboratory investigations confirmed the infection to be caused by a dengue serotype 3 virus. This case reasserts the importance of returning travellers as sentinels of unknown outbreaks occurring in other countries, and highlights how the initial symptoms of dengue fever resemble those of other haemorrhagic fevers, hence the importance of prompt isolation of patients until a final diagnosis is reached.

Detection of interleukin-2 in addition to interferon-gamma discriminates active tuberculosis patients, latently infected individuals, and controls

Effective control of tuberculosis (TB) includes discrimination of subjects with active TB from individuals with latent TB infection (LTBI). As distinct interferon (IFN)-gamma and interleukin (IL)-2 profiles of antigen-specific T-cells have been associated with different clinical stages and antigen loads in several viral and bacterial diseases, we analysed these cytokines in TB using a modified QuantiFERON-TB Gold In Tube test. Detection of IL-2 in addition to IFN-gamma distinguishes not only Mycobacterium tuberculosis-infected subjects from healthy controls, but also individuals with LTBI from active TB patients. This may help to improve diagnostic tests for TB.

Influenza vaccine administration in rheumatoid arthritis patients under treatment with TNFalpha blockers: safety and immunogenicity

Twenty-eight patients with low-moderate, stable rheumatoid arthritis (RA), under treatment with tumor necrosis factor (TNF) alpha blockers, were immunized at least once with non-adjuvanted trivalent influenza vaccine during three consecutive influenza seasons. Antibodies toward A influenza antigens significantly increased and reached protective levels, still detectable 6 months after vaccination, both in RA patients and healthy controls. Response to B antigen instead was only observed from the second year for healthy controls and in the third year for patients. No significant difference in disease activity and anti-nuclear antibodies was observed as a consequence of vaccine administration, whereas T regulatory cells showed a significant increase 30 days after immunization in RA patients. This study confirms safety of influenza vaccine administration in RA patients treated with TNFalpha blockers. The cohort follow-up revealed the overcoming of poor B vaccine antigen immunogenicity via repeated vaccinations. Finally, protective antibody response was still observed 6 months after vaccination.

Influenza vaccine administration in patients with systemic lupus erythematosus and rheumatoid arthritis. Safety and immunogenicity

OBJECTIVE

To evaluate immunological safety and immunogenicity of influenza vaccine administration in patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA).

PATIENTS AND METHODS

Twenty-four patients with low and/or stable disease activity 14 with SLE (mean age 43.42+/-12.18 years; 13 women) and 10 with RA (mean age 51+/-14.57 years; 9 women), diagnosed on the basis of the American College of Rheumatology criteria, have been immunized with trivalent split influenza vaccine without adjuvant. Further 24 non-vaccinated patients, 14 with SLE and 10 with RA, and 10 vaccinated healthy subjects, all age- and sex-matched, were used as controls. The patients underwent clinical and laboratory (specific anti-influenzavirus antibodies, auto-antibodies, peripheral blood lymphocyte subpopulations) evaluation before and 30 days after vaccination; auto-antibodies were also assessed at 90 days and disease activity at 90 and 180 days.

RESULTS

The specific antibody response towards the three used antigens (A/New Caledonia/20/99, A/Moscow/10/99, and B/Shangdong/7/97) significantly increased in both patients and healthy controls, without any significant difference between them. No significant difference could instead be observed on the clinical activity, auto-antibodies, and peripheral blood lymphocyte subpopulations before and after vaccination, and between patients and controls.

CONCLUSIONS

Trivalent split influenza vaccine without adjuvant seems to be safe and immunogenic in patients with SLE and RA, provided that only patients with low and/or stable disease activity are selected.

Chylomicron retention disease--the role of ultrastructural examination in differential diagnosis

Three children with malabsorption presumably caused by celiac disease had undergone jejunal biopsy. While a histological examination revealed microvacuolization of enterocytes in the absence of celiac lesions, an ultrastructural investigation disclosed numerous chylomicrons and larger lipid vacuoles inside the cytoplasm of enterocytes, mostly in the supranuclear region. No chylomicrons were evident in the interstitium between adjacent enterocytes, as observed in normal subjects. These ultrastructural findings allowed for the diagnosis of "Chylomicron retention disease" (CRD). CRD was described for the first time by Anderson in 1961, and it is included in the group of disorders of biosynthesis and secretion of B apolipoproteins (apoB). This disease, in particular, appears to result from a specific defect involving the secretion of lipoproteins containing apoB-48 from the gut, with the complete absence of post prandial chylomicrons in the sera. CRD needs to be recognized early because of its adverse effects on growth and its potential for neurological and ocular complications, and the ultrastructural identification of chylomicron-size lipid droplets clustered in the enterocytes, with the absence of fat outside the cells, represents the gold standard to identify CRD. together with clinical aspects and laboratory measurements. In this study, we describe the histological and ultrastructural aspects observed in three pediatric cases of CRD.

Modified autonomic balance in offsprings of diabetics detected by spectral analysis of heart rate variability

This study was performed to evaluate the influence of family history for non-insulin-dependent diabetes mellitus (NIDDM) on autonomic balance. The latter was assessed by spectral analysis of heart rate variability (SA-HRV) and by analyzing the relative contribution of low-frequency (LF) and high-frequency (HF) components. Twenty glucose normotolerant offsprings of NIDDM parents and 20 controls underwent a 1-hour continuous electrocardiogram (ECG). LF and HF (mean +/- SEM in normalized units [NU]), respectively increased and decreased in offspring versus controls. The LF/HF ratio (mean +/- SEM) significantly increased (LF/HF = 3.25 +/- 0.7 v 1.45 +/- 0.5, P <.0001 offsprings v controls). To test a stimulated response, a passive tilting (+ 90 degrees ) after 30 minutes of bed rest (0 degrees ) was performed in a subsample of subjects (10 offsprings v 10 controls). During bed rest, we found significantly higher values of the LF/HF ratio in offsprings versus controls (1.93 +/- 0.3 v 1.08 +/- 0.2, P <.05), whereas in the head-up position, the LF/HF ratio value increased to the same levels in the 2 groups (6.48 +/- 1.3 v 6.89 +/- 1.4, not significant [NS]). NIDDM family history is characterized in the basal condition by an imbalance of the autonomic system, which, compared with controls, is expressed by a higher weight of sympathetic and a lower weight of parasympathetic components. No significant differences can be found under stimulated conditions.

A global review of legislation on HIV/AIDS: the issue of HIV testing

OBJECTIVE

Critical review of worldwide legislation on HIV/AIDS, with a focus on the issue of HIV testing, mainly in a military context.

DESIGN

Analysis of health legislation on HIV/AIDS among 121 of the 191 member states of the World Health Organization (WHO), representing 85% of the world's population.

METHODS

The WHO Directory of Legal Instruments Dealing with HIV Infection and AIDS has been the main source consulted. Relevant findings of two global surveys were used to examine HIV testing in the military.

RESULTS

AIDS cases are reportable in 60% of the 121 countries, whereas HIV infections in no more than 26%. Notifications are kept confidential by law in 20% of countries. Only 17% have developed HIV-specific legislation against social discrimination, whereas 10% have passed legislation establishing financial reimbursement to those who have acquired HIV infection after injection of HIV-contaminated biologic material, support for occupational risk, and/or social protection for patients. Only 42% of the 121 countries report having legal instruments that require screening of donated blood. Legislative measures that address, generally in a prescriptive but sometimes also in a protective way, vulnerable groups, such as commercial sex workers, men who have sex with men, injecting drug users, and recipients of multiple transfusions of blood or blood-derivatives, are reported in 27% of countries. Other categories considered potentially vulnerable, for which specific legislation has been passed, include immigrants (17% of countries), prisoners (5%), and health personnel (14%). Further legislative measures for HIV prevention address testing pregnant women in the prenatal period (7% of countries), supporting condom promotion (11%), measures requiring quarantine, isolation, or coercive hospitalization of HIV-infected people or AIDS patients (9%), or imposing penal sanctions for HIV-infected people who deliberately expose others to the risk of transmission (10%). A National AIDS Committee responsible for addressing issues related to HIV/AIDS has been established by law in 39% of the 121 countries. Global surveys show that 27 countries carry out compulsory HIV screening on recruitment of military personnel.

CONCLUSIONS

These data represent a useful tool to make governments aware of the problem of underreporting of legal instruments to the WHO and of the need to promote legislation in line with the idea that public health and human rights are complementary, not conflicting, goals.

Surveillance of infectious diseases in the Italian military as pre-requisite for tailored vaccination programme

Surveillance and control of infectious diseases in the Italian military include prompt reporting of all occurring cases and prophylaxis through compulsory vaccination practices. The last mandatory immunisation programme in the Italian military was launched in 1998 (more than 10 years after the previous programme was introduced in 1986-1987) and it was planned according to the epidemiological data herein reported. The incidence rates (number of cases x 100000 subjects) of infectious diseases notified during the period 1976-1980 were compared with the corresponding figures notified 15 years later (1991-1995). An increase of three airborne-transmitted viral diseases--varicella, rubella and measles--counterbalanced by a decrease of other infectious diseases, such as mumps, typhoid fever, tuberculosis, viral hepatitis, scabies, syphilis and gonorrhea, was observed. This may be related to improvements in the general hygienic conditions and more responsible sexual behaviour among Italian military recruits. Moreover, incidence rates of cases notified in the military were compared with those notified in the general population of the same sex- and similar age-range (15-24 years) over a 12-year period (1986-1997), to monitor the epidemiological situation in relation to (a) potential risk factors specifically linked to military life and (b) protective effects induced by specific vaccinations. Airborne-transmitted viral diseases, such as varicella, rubella, measles and mumps--which are usually underreported among civilians--show higher incidence rates in the military. Meningococcal meningitis shows higher incidence rates in the military in 1986 and 1987 (before the introduction of mandatory specific vaccination) as well as in 1995-1997 (main etiologic agent N. meningitidis serogroup B); similar rates were instead observed in the other years. Incidence rates for typhoid fever are generally lower in the military, despite the community life, probably reflecting the protective efficacy of specific vaccine. Hepatitis A and B show similar rates between military and civilian population. Finally, pulmonary tuberculosis generally shows higher rates in the military. These data therefore allow the conclusion that the only infectious diseases, for which possible risk factors in the military life may be hypothesised, seem to be meningococcal meningitis and perhaps pulmonary tuberculosis. Epidemiological surveillance of infectious diseases in the military as a pre-requisite for appropriate public health intervention strategy represents a good model to be followed also in larger contexts.

Neuronal ceroid lipofuscinosis: an ultrastructural, genetic, and clinical study report

The term "neuronal ceroid lipofuscinosis" (NCL) describes a complex of inherited neurodegenerative conditions associated with storage of lipopigments in brain tissue. In 1989 Dyken proposed a classification of NCL based on the age, clinical symptoms, and ultrastructural aspects of the lipopigments. At the ultrastructural level it is possible to distinguish 5 different patterns of osmiophilic lipopigments: usual lipofuscin, fingerprint deposits, granular profiles, curvilinear bodies, and microtubular aggregates. The concept that each ultrastructural pattern was the counterpart of a specific clinical type has been proved not to be true. Advances in molecular genetic techniques have allowed the identification of defective genes and their protein products in several NCL clinical forms. Ceroid lipofuscin deposits may be ultrastructurally observed not only in neuronal cells, but also in several other sites, such as trophoblastic cells, thus permitting prenatal diagnosis. In spite of recent advances in immunohistochemical identification of biochemical markers, the ultrastructural identification of lipofuscinic pigments remains the gold standard to identify NCL, together with clinical aspects and respective gene defects. This study describes the ultrastructural aspects observed in 8 cases of NCL syndromes (3 juvenile, 3 infantile, 1 late infantile, and 1 congenital clinical form). In these patients, genetic analysis was also performed.

Tuberculin skin reactivity in Italian military recruits tested in 1996-1997

In 1996-1997 data was collected and a Mantoux tuberculin test performed in 2882 Italian military recruits aged 18-23 years in order to establish the prevalence of tuberculin reactivity. In addition, the annual risk of infection, defined as the probability that a non-infected individual would be infected during the following year, was calculated. Of the 2882 recruits, 513 had received a BCG vaccination, the remaining 2369 had not. The overall prevalence of subjects with a tuberculin skin reaction size >5 mm (the cut-off point for positivity corresponding to the antimode in the reaction size frequency curve) was 6.1% (144/2369). The prevalence of skin reactivity increased with age but remained similar when related to area of residence, duration of father's school education and family size. The same general trend was observed if the standard pre-established cut-off point of 10 mm was used. In this case the overall prevalence of a positive skin reaction was 4% (95/2369). The annual risk of infection was 0.3% for a prevalence of tuberculin skin reactivity of 6.1% (cut-off point 5 mm) and 0.19% for a prevalence of 4% (cut-off point 10 mm). Analysis of the population sample vaccinated with BCG showed a lack of correlation between the positive reaction after vaccination reported retrospectively by the subject and the current skin reaction observed by the physician in this study (K = 0.254). Moreover, a significant difference was observed between the skin reaction in subjects vaccinated with BCG in 1993-1994 (average size 12.5 mm) and that of subjects vaccinated in 1995-1996 (average size 10.1 mm, P<0.01), probably as a consequence of mycobacteria circulating in the general population which act as a natural booster in people already vaccinated with BCG. A booster effect of tuberculin in Mantoux assays also cannot be excluded.

Myofibroblastic tumours: neoplasias with divergent behaviour. Ultrastructural and flow cytometric analysis

Myofibroblasts are spindle cells having ultrastructural features in common with smooth muscle cells and fibroblasts. In the last few years, tumours have been described in which myofibroblasts represent not only a reactive mechanism but also a true neoplastic component. They constitute new nosologic entities which might be termed "myofibroblastic tumours". Tumours with benign and, rarely, malignant behaviour are reported to belong to this group of lesions. Recently, a third tumour type with borderline biological course, named "inflammatory myofibroblastic tumour" (IMT), has been identified, a condition that has been regarded as a benign and reactive disorder for a long time. Only in recent reports has been demonstrated that, in spite of an apparently benign morphological pattern, some cases of IMT have a malignant course. In this connection, DNA analysis by flow cytometry is a valuable diagnostic tool, because it allows identification of the ploidy status, a procedure that is often useful for predicting the nature and the biological behaviour of the lesion. In this study, 11 cases of myofibroblastic tumours were examined retrospectively by evaluating clinicopathological features and DNA ploidy status by flow cytometry. The diagnosis of myofibroblastic tumour was confirmed by performing histology, immunohistochemistry, and electron microscopy in all patients. In detail, these 11 cases were composed of 1 benign myofibroblastoma, 1 myofibrosarcoma and 9 IMTs. Among these myofibroblastic tumours, all those with local recurrence or distant metastases (one myofibrosarcoma and three IMT) showed an aneuploid cell population demonstrable by flow cytometric analysis, whereas the other cases with benign course (one benign myofibroblastoma and six IMT) exhibited an euploid DNA content. These data suggest the following: a) Besides the rare myofibroblastomas and myofibrosarcomas, IMTs represent a larger group of lesions with potentially different biological and clinical course. b) DNA flow cytometric analysis is a reliable tool that support histopathological examination in characterizing those cases of IMT that, though being malignant, mimic benign lesions. Consequently, it establishes the basis for a different therapeutic approach according to the euploid or aneuploid DNA content.

Incidence of Helicobacter pylori infection in a cohort of Italian military students

Prevalence and incidence of Helicobacter pylori infection among 250 Italian military students were studied using specific IgG antibodies. Subjects susceptible at enrollment were evaluated during a 10-month follow-up period, when two serum samples were collected after 5 and 10 months, respectively. Samples were also analyzed for anti-CagA (a protein associated with virulent H. pylori strains) IgG antibodies. Finally, spectrotypic analysis by isoelectric focusing and reverse blotting (IEFRB) was performed in the majority of positive samples. Forty-three out of 250 (17.2%) were positive at the time of enrollment, a seroprevalence rate very similar to that observed in a larger Italian military population 5 years earlier. Among the 207 susceptible subjects, two seroconverted at 5 months after enrollment; they were still positive at the end of follow-up (incidence rate of 1.16 per 100 person/years of exposure). This data suggests a spread of H. pylori in the Italian military population that is not negligible. Nearly all anti-H. pylori-positive subjects were also CagA antibody positive (agreement percentage: 97.6%; K = 0.91), suggesting that the large majority of H. pylori strains were of the virulent type. Sixty-four percent of positive sera presented an oligoclonal spectrotype, which seems to be a hallmark of humoral immune response to H. pylori.

Lipoprotein (a) and apoprotein B in an apparently healthy population of fighter pilots and ground personnel: their significance as potential markers of atherosclerosis

BACKGROUND

Individuals who carry cardiovascular risk factors (CVRF) have a higher incidence of cardiovascular pathology. Among the most commonly screened CVRF are apoprotein A and B and lipoprotein (a), which represent 'independent' risk factors for atherosclerosis. In the air force community, cardiovascular pathology has been reported as the primary reason for grounding pilots.

DESIGN

The aim of this study was to evaluate the frequency of CVRF in an apparently healthy population of military fighter pilots (group B, n = 50), and military ground personnel (group A, n = 50) who were matched for age, sex and body mass index but not involved in flight activity, and to evaluate whether any particular pattern of CVRF might be related to flight.

METHODS

Each subject fasted overnight, and underwent the following measurements: blood pressure and resting ECG recording; and determination of serum levels of total and high-density lipoprotein cholesterol, triglycerides, uric acid and plasma levels of glucose. In addition, serum levels of apolipoprotein A, B and lipoprotein (a) were detected.

RESULTS

An overall risk index for coronary artery disease was calculated using the Framingham equation. This risk index was slightly but not significantly increased in group A compared with group B. By contrast, a significant increase in both apoprotein B (P < 0.005) and lipoprotein (a) (P < 0.0005) was found in group B compared with group A. No significant differences between groups were detected for the other parameters evaluated.

CONCLUSIONS

We suggest the presence in group B of an underlying trend towards the development of atherosclerosis, which may not be identified by a routine approach. Moreover, on a purely theoretical basis with no experimental evidence, the issue of the possible pathophysiological mechanism of these findings and their relationship to flight environment is also addressed.

Sequence of metabolic changes during X-ray-induced apoptosis

A cell population undergoing apoptosis usually contains varying proportions of cells in the diverse stages of the process, from very early continuously through to secondary necrosis. This heterogeneity acts as a confounding factor in metabolic studies if a general population is investigated. Using fluorescent probes and multiparameter flow cytometry, we report on metabolic changes occurring during X-ray-induced apoptosis in human peripheral blood lymphocytes and relate the observed alterations to cells at various phases of the process assessed by monitoring the progressive loss of selective plasma membrane permeability. Data show that alterations of mitochondria cardiolipin and a reduction of plasma membrane potential are rather early events as they commence in cells which still possess an impermeable plasma membrane. Conversely, mitochondrial transmembrane potential is impaired only when plasma membrane permeability starts to be altered, that is, in relatively later apoptotic cells, thereby reflecting the complexity of mitochondria demise during apoptosis. The prooxidant/antioxidant balance is altered in cells in early apoptosis with a correlated increase of prooxidants and depletion of thiols, the latter indicative for the progressive impairment of this detoxifying mechanism. The imbalance in prooxidant/antioxidant remained evident through apoptosis suggesting that oxidative damage starts early and then continues, eventually leading to cellular disruption. Assessing cell transit through the apoptotic process and coupling the observed metabolic changes to selected stages of the process enables one to improve the understanding of the temporary sequence of biochemical phenomena occurring in a given model.

Isoelectricfocusing and reverse blotting as a diagnostic tool in pediatric HIV infection

BACKGROUND

Early diagnosis of perinatally acquired HIV-infection is based on either direct HIV detection--by means of viral culture and/or PCR--or anti-HIV antibody detection. However, due to the passive, transplacental passage of maternal immunoglobulin G, antibody detection is nor reliable until 15-18 months of age. In this regard, clonotypic analysis of specific antibodies performed by isoelectricfocusing and reverse blotting (IEF-RB) can be very helpful, as it recognizes possibly different patterns between mother and infant.

OBJECTIVES

We used IEF-RB in order to analyze the kinetics of development of anti-HIV antibodies in infants born to seropositive mothers.

STUDY DESIGN

Sera from ten mother/infant pairs (all mothers were HIV-infected) were retrospectively analyzed in order to detect different patterns, between mother and infant, in anti-gp120 V3-loop clonotype.

RESULTS

We diagnosed the real HIV status of the examined infants no later than month 6 and in one case as early as month 2.

CONCLUSIONS

Considering the small size of sample number, these data are preliminary and should be confirmed by larger scale studies. However, they show IEF-RB, when applied to infants born to seropositive mothers, may be useful in evaluating the infants' dynamics of anti-HIV humoral immune response.

Effect of rIL-2 treatment on anti-tetanus toxoid response in the elderly

To explore the effects of interleukin-2 (IL-2) treatment in a vaccination protocol in the elderly, we administered low-dose rIL-2 to a group of aged subjects before primary tetanus toxoid immunization. A specific antibody response was detectable in the serum of 6/8 treated individuals after primary immunization, but in only 2/6 untreated controls; following antigenic boosting, specific antibody levels remained relatively unchanged in all the seroconverters. The data were confirmed by studying the ability to produce tetanus-specific antibodies in vitro, and by isoelectrofocusing analysis of serum anti-tetanus antibodies; this latter study showed a more restricted clonal response to the immunogen in untreated individuals. On the other hand, the study of the in vitro proliferative response to tetanus toxoid did not evidence clear differences between the two groups. On the whole, these data seem to indicate that a short-term rIL-2 treatment is able to potentiate the antibody response to tetanus toxoid, and may be a useful tool to improve humoral responses to vaccines in aged subjects.

Evaluation of stress induced by flight activity by measuring the hormonal response

The aim of the present study was to quantitatively investigate the different levels of adaptation to flight and to evaluate the hormonal response to flight activity as a possible reliable tool to quantify the level of stress induced by flight. The hormonal response of growth hormone (GH), cortisol, and prolactin (PRL) to flight activity was evaluated in a group of student pilots (n = 11; all male; age 20 +/- 2 years) and flight instructors (n = 11; all male; age 27 +/- 2 years) of an Italian Air Force flight school. Blood samples were obtained immediately before and after a training flight session. Hormonal determination by RIA technique after flight showed a significant increase of plasma hormonal levels of GH, PRL, and cortisol in the students. Conversely, in the instructors only GH showed a significant increase versus preflight values, whereas PRL and cortisol did not show significant differences. Moreover, preflight hormonal levels of GH and PRL were significantly higher for student pilots compared to the same values for flight instructors. The data lead to establishing a close correlation between the hormonal response to flight activity and the level of tolerance and adaptation to flight-induced stress.

Probing chromatin structure in the early phases of apoptosis

A typical flow cytometric marker of apoptosis is the appearance of a hypodiploid peak. This phenomenon is related to the chromatin fragmentation and loss that occurs during the late stages of the process. We describe herein the changes occurring at the chromatin level in purified nuclei preparations obtained from human peripheral blood mononuclear cells in a time-course study, including the simultaneous evaluation of nuclear proteins and DNA stainability, light-scattering properties, and spectrophotometric determination of the protein content. An augmentation of fluoroscein isothiocyanate (FITC) stainability was noticed as early as 1 h after irradiation. As this phenomenon is not correlated to changes in actual protein content, one can conclude that modifications of basic protein accessibility occur from the early phases of the apoptotic process. Also DNA stainability augmented with time, generating the transient appearance of a hyperdiploid peak that preceded the appearance of the hypodiploid peak typical of the late stages of the process, and that shared with the latter the same light-scattering properties. Chromatin status was further explored by staining apoptotic nuclei using DNA probes with peculiar molecular weight. Propidium iodide (PI) and ethidium bromide (EB), but not the much bulkier 7-aminoactinomycin D (7-AAD), identified the nuclei with a transient increase in DNA stainability confirming that an increased dye accessibility to binding sites was responsible for the phenomenon. Remarkably, all dyes identified the same proportion of hypodiploid nuclei when an apoptotic nucleus shed its fragmented chromatin. Control experiments included differential interference contrast and fluorescence microscopy that showed the purity of nuclei preparations and the typical morphological apoptotic features. Finally, the simultaneous evaluation of DNA by PI and nuclear proteins by FITC in a time course study allowed a thorough assessment of changes occurring at the chromatin level in the diverse stages of apoptosis. It is suggested that proteolysis precedes endonucleolysis and probably renders it easier the final endonucleolytic step leading to DNA fragmentation and loss.

Inflammatory myofibroblastic tumor (inflammatory pseudotumor): DNA flow cytometric analysis of nine pediatric cases

BACKGROUND

Inflammatory myofibroblastic tumor or inflammatory pseudotumor is an uncommon lesion reported in various organs and believed to be a non-neoplastic reactive inflammatory condition. The concept of benign lesion has been recently challenged from both clinical demonstration of recurrence and cytogenetic evidence of acquired clonal chromosomal abnormality. Because DNA aneuploidy can be a useful marker for neoplasia, we analyzed nuclear DNA content of these lesions using flow cytometry.

METHODS

In this study, inflammatory myofibroblastic tumors from nine children were examined retrospectively by evaluating clinicopathologic features and ploidy. DNA ploidy status was analyzed by flow cytometry in nuclei isolated from paraffin-embedded tumor tissues.

RESULTS

Three of the nine patients had local recurrence or distant metastases. Flow cytometric DNA analysis revealed five of the nine cases were diploid and four hyperdiploid (DNA indices 1.14, 1.16, 1.19, and 1.33). All lesions had a low S-phase fraction. Samples from the three subjects with clinical recurrence were all hyperdiploid.

CONCLUSIONS

The present data indicate that flow cytometry identifies aneuploidy (hyperdiploidy) in approximately half of the cases of inflammatory myofibroblastic tumors. This feature appears to reflect a more aggressive biologic behavior. In addition to the reported cytogenetic abnormalities, our data suggest that inflammatory myofibroblastic tumor, generally considered a benign reactive inflammatory process, may evolve as a distinct, potentially malignant, lesion. Therefore, flow cytometric DNA analysis is a suitable tool to provide the clinician with both diagnostic and prognostic information and to individuate the most feasible therapeutic approach.

Flow cytometric analysis of the early phases of apoptosis by cellular and nuclear techniques

The early events occurring during apoptosis at the plasma membrane, chromatin, and mitochondrial levels were investigated in freshly isolated irradiated human lymphocytes, growth factor-deprived cultured human lymphocytes, and dexamethasone (DEX)-treated murine thymocytes. In intact, unfixed cells, evaluation of the light scatter properties and of DNA stainability with ethidium bromide (EB) allowed a cell subset suggestive for initial apoptosis to be identified. The apoptotic nature of these cells was confirmed by cell sorting in irradiated human lymphocyte model. EB could not be substituted for by propidium iodide, indicating that the nature of DNA probe used is of major importance for detecting initial apoptotic changes. Because mitochondria are thought to represent a primary target during apoptosis, we measured the uptake of mitochondria transmembrane potential sensitive (Rhodamine 123) and nonsensitive (10-nonyl-acridine-orange) probes concomitantly with EB uptake. Cells starting apoptosis had an enhanced incorporation of both mitochondria dyes, which in combination with EB identified several cell subsets. This suggests that complex alterations in mitochondrial structure and functioning occur in the early stages of apoptosis. To investigate phenomena occurring at the chromatin level in similar phases of apoptosis, irradiated human lymphocytes and DEX-treated murine thymocytes were disrupted and DNA stainability assessed in nuclear suspensions. A transient increase in DNA stainability, i.e., the appearance of distinct hyperdiploid peaks in the human model and a generalised upward shift of the G0/1 peak in the murine model, was observed in the early phases of apoptosis concomitantly with specific alterations in light scattering properties. These findings suggest that chromatin texture is altered in early apoptosis and affects DNA stainability.

Anti-V3 loop spectrotype in HIV-infected individuals during zidovudine therapy

In order to investigate the role played by zidovudine (ZDV) as immune modulator, particularly on B-cell response, the anti-V3 loop spectrotype in 115 sera from 26 HIV-infected individuals was evaluated, prior to and during treatment with ZDV, by isoelectric focusing and reverse blotting (IEF-RB), a technique useful for indirectly measuring the activity and the number of B-cell clones. All 18 patients showing seroreactivity by IEFRB displayed a clear oligoclonal banding pattern, with no change in the spectrotype (i.e. new bands), in sequential analysis over the course of therapy. Only minor changes in band intensity were found, without any correlation with ZDV treatment or CD4+ cell count. In addition, among the sera reactive in spectrotypic analysis, the percentage of those with p24 antigen positivity was significantly lower than those with no detectable p24 antigen (19.8% vs 80.2%, respectively, p = < 0.0001, Fisher's exact test). In conclusion, it could not be demonstrated by IEFRB that there was any effect of ZDV on the activity and the number of anti-V3 specific B-cell clones. This data is in line with previous studies showing the constancy of anti-gp120 antibody spectrotype over the long course of the disease.

Inflammatory myofibroblastic tumor (inflammatory pseudotumor): DNA flow cytometric analysis of nine pediatric cases

BACKGROUND

Inflammatory myofibroblastic tumor or inflammatory pseudotumor is an uncommon lesion reported in various organs and believed to be a non-neoplastic reactive inflammatory condition. The concept of benign lesion has been recently challenged from both clinical demonstration of recurrence and cytogenetic evidence of acquired clonal chromosomal abnormality. Because DNA aneuploidy can be a useful marker for neoplasia, we analyzed nuclear DNA content of these lesions using flow cytometry.

METHODS

In this study, inflammatory myofibroblastic tumors from nine children were examined retrospectively by evaluating clinicopathologic features and ploidy. DNA ploidy status was analyzed by flow cytometry in nuclei isolated from paraffin-embedded tumor tissues.

RESULTS

Three of the nine patients had local recurrence or distant metastases. Flow cytometric DNA analysis revealed five of the nine cases were diploid and four hyperdiploid (DNA indices 1.14, 1.16, 1.19, and 1.33). All lesions had a low S-phase fraction. Samples from the three subjects with clinical recurrence were all hyperdiploid.

CONCLUSIONS

The present data indicate that flow cytometry identifies aneuploidy (hyperdiploidy) in approximately half of the cases of inflammatory myofibroblastic tumors. This feature appears to reflect a more aggressive biologic behavior. In addition to the reported cytogenetic abnormalities, our data suggest that inflammatory myofibroblastic tumor, generally considered a benign reactive inflammatory process, may evolve as a distinct, potentially malignant, lesion. Therefore, flow cytometric DNA analysis is a suitable tool to provide the clinician with both diagnostic and prognostic information and to individuate the most feasible therapeutic approach.

Potentiation of human polymorphonuclear leukocyte activation by atrial natriuretic peptide. Inhibitory effect of carnitine congeners

Polymorphonuclear leukocytes (PMN), atrial natriuretic peptide (ANP) and leukotriene B4 (LTB4) reportedly play a major role in ischemia/reperfusion states of coronary artery disease. We sought to determine whether ANP and LTB4 cooperate in inducing PMN activation with consequent modulation of membrane molecules required for adherence to endothelium and myocardial cells, namely CD11b and L-selectin and the release of toxic oxygen radicals. ANP (from 10(-16) to 10(-8) M), LTB4 (from 10(-10) to 10(-6) M) and combinations of the two were incubated with normal PMN at 37 degrees C for 15 minutes. Membrane molecules modulation was measured by flow cytometry using specific monoclonal antibodies. Hydrogen peroxide production, an indicator of the capacity of PMN to release toxic oxygen species was quantified by flow cytometry using the peroxide-sensitive fluorescent probe dichlorofluorescein diacetate. ANP, uneffective when used alone, dose-dependently potentiated the PMN response to LTB4 (10(-9) M) as evidenced by an up-regulation of CD11b expression and peroxide production, and a down-regulation of L-selectin expression. These effects were prevented dose-dependently by the protein kinase C (PKC) inhibitor staurosporine (from 10 to 160 microM). Two carnitine congeners, palmytoylcarnitine (tested from 125 pg to 2 micrograms/ml) that also possesses an established ability to antagonise PKC and L-carnitine (tested from 12 to 200 ng/ml) were also effective. These data indicate that ANP potentiates LTB4 in inducing PMN mobilization and activation with a possible consequent detrimental effect on cardiac tissue and evisages the usefulness of PMN metabolism modulators.

Protective actions of L-carnitine and acetyl-L-carnitine on the neurotoxicity evoked by mitochondrial uncoupling or inhibitors

The mechanism for the pathological increase in cell death in various disease states e.g. HIV immunodefficiency or even ageing or Alzheimer's disease, occurs by complex and as yet undefined mechanism(s) related to immunological, virological or biochemical disturbances (i.e. energy depletion, oxidative stress, increased protein degradation). We have studied mitochondrial uncoupling or inhibitor toxicity on neurones at the cellular level and at the mitochondrial level using rhodamine (Rh123) and 10-nonylacridine orange (NAO) fluorescence with confocal microscopy. Blockade of the mitochondrial chain complexes at various points was studied. The possible protective effects of the compound L-carnitine, which plays a central role in mitochondrial function, was tested in this form of neurotoxicity. It appears that L-carnitine and its acetylated form, acetyl-L-carnitine, can attenuate the cell damage, as assessed by lactate dehydrogenase (LDH) release, evoked by the uncoupler, p-(trifluoromethoxy)phenylhdyrazone (FCCP), or by the inhibitors, 3-nitropropionic acid (3-NPA) or rotenone. Further, the FCCP-induced inhibition of Rh123 uptake was antagonized by the preincubation of cells with L-carnitine. Since such neurotoxic mechanisms may be operating in the various pathological forms of myotoxicity and neurotoxicity, these observations suggest potential for a therapeutic approach.

Spectrotypic analysis of antibodies to Helicobacter pylori in patients with antral gastritis and duodenal ulcer

AIMS

To investigate the anti Helicobacter pylori (H pylori) spectrotype associated with (a) antral gastritis and duodenal ulcer; (b) the H pylori eradicating treatment.

METHODS

Spectrotypic analysis was performed by isoelectric focusing and reverse blotting (IEFRB) in a cross sectional study on sera from 70 patients with antral gastritis and duodenal ulcer. In addition, a longitudinal study was performed on 40 of these patients (20 with antral gastritis and 20 with duodenal ulcer) who underwent eradicating treatment.

RESULTS

The cross sectional study showed that the oligoclonal spectrotype was present in 74% of antral gastritis patients and in 85% of duodenal ulcer patients. In only a minority of subjects (23% with antral gastritis and 3% with duodenal ulcer) was a polyclonal spectrotype observed. The longitudinal study showed a reduction in the intensity of the spectrotypic bands in 5/10 antral gastritis patients with eradicated H pylori as opposed to only 2/10 patients without eradication. A reduction was also observed in 6/11 eradicated v 0/9 non-eradicated patients with duodenal ulcer. Collectively, a reduction in the spectrotype was observed in 11/21 patients (52%) who--independently of the disease--underwent H pylori eradication, as opposed to 2/19 of the non-responder patients (10.5%). The polyclonal spectrotype was found exclusively in four patients with antral gastritis, all belonging to the group without eradication of H pylori after eradicating treatment.

CONCLUSIONS

The anti H pylori oligoclonal spectrotype is the most common pattern observed in patients with antral gastritis and duodenal ulcer. After H pylori eradicating treatment the spectrotype does not change qualitatively, but the polyclonal pattern seems to be predictive of a poor response to eradication.

Rhodamine 123: a useful probe for monitoring T cell activation

The T cell activation pathway involves an increase in mitochondrial activity. This can be evaluated in individual cells using the fluorescent probe rhodamine 123 (Rh123) and flow cytometry. Peripheral blood mononuclear cells (PBMC) were stimulated with optimal concentrations of phytohaemagglutinin (PHA), superantigens (Sag) SEA and SEC2, and allogeneic cells. Activation kinetics were followed at days 1, 2, 4 and 7. In all activation conditions, Rh123 uptake was augmented with the CD25 expression, cell size, and DNA synthesis. Rh123 uptake reflected an increase in mitochondrial activity and mass, as assessed by experiments in which Rh123 was substituted for by the 10-nonyl acridine orange, which stains mitochondria in an energy-independent manner. The spectral characteristics of Rh123 allowed us to double stain cells with Rh123 and phycoerythrin-conjugated monoclonal antibodies. In PHA-activated cultures, CD4+ and CD8+ cells incorporated essentially the same amount of Rh123 at all time points, suggesting that the two subsets did not differ in their activation kinetics. Accordingly, after 1 week of culture, no significant modification in the CD4/CD8 ratio was observed. Sag-activated CD4+ cells incorporated a higher amount of Rh123 than did CD8+ cells and preferentially expanded after 1 week of culture as indicated by the increase in the CD4/CD8 ratio. The different behavior of the CD4 and CD8 subsets observed by dual color flow cytometry in the PHA and Sag models was confirmed using purified CD4+ and CD8+ cell preparations obtained by immunomagnetic sorting. CD4+ cells were also the preferential target in the allogeneic model, although the magnitude of the phenomenon was lower than in the Sag model. Present data indicate that Rh123 is a reliable marker for monitoring the mitochondrial compartment during T cell activation. The possibility of phenotyping Rh123-stained cells adds to the applicability of the probe.

Flow cytometric approach to human polymorphonuclear leukocyte activation induced by gingival crevicular fluid in periodontal disease

In gingival pockets of patients with periodontal disease, polymorphonuclear leukocytes (PMN) are in contact with a peculiar exudate, the gingival crevicular fluid (GCF). Because of the pivotal role played by PMN in periodontal disease, we evaluated the ability of GCF in modulating normal human PMN. GCF was obtained from two gingival sites with severe periodontitis (SP) and two gingival sites with only mild periodontitis (MP) in 12 patients. Purified PMN were exposed to GCF from SP and MP sites and, as a control, to sterile culture medium. GCF activity was evaluated by monitoring the modulation of membrane molecules relevant to cell function. Compared to control medium, GCF from SP and MP sites was able to induce an activation status in PMN evidenced by an increased CD11b (62 +/- 9% and 28 +/- 7%, respectively) and f-Met-Leu-Phe (56 +/- 5% and 31 +/- 7%, respectively) receptor expression, with a concomitant reduction of CD62L expression (56 +/- 8% and 23 +/- 7%, respectively). Thus, reflecting the clinical status, GCF from SP sites was significantly more efficient in affecting PMN than GCF from MP sites. Cell size modifications, evaluated as an additional indicator of PMN activation, were consistent with membrane molecule modulation. The difference in PMN-activating capacity between SP and MP was abrogated by the successful completion of an appropriate periodontal therapy that dramatically improved clinical status. This is the first direct demonstration that GCF from periodontitis has the capacity to activate normal resting PMN and that this capacity reflects the magnitude of the inflammatory process that takes place in the gingiva.

Humoral response to influenza hemagglutinin: oligoclonal spectrotype and failure of thymopentin as immunoadjuvant

Influenza remains a serious cause of illness and death among certain populations. Influenza vaccines in use at present are of limited effectiveness due to the high variability of the virus, and trials all over the world are in progress to enhance their immunogenicity. Conflicting results, in fact, have been reported about the immune response to influenza vaccination in diverse populations. In this paper we analyzed the antibody response to the hemagglutinin (HA) of the H3N2 A/Shangai 16/89 strain, which was included into the trivalent 1991-92 influenza vaccine, in four groups of subjects: 8 healthy young, 13 human immunodeficiency virus (HIV)-infected and 37 elderly healthy people, 9 of whom were treated with thymopentin (TP-5). Our results show levels of anti-HA IgG before vaccination in HIV-infected and elderly people significantly lower than those of normal young subjects. After vaccination, HIV-infected and elderly healthy people showed a significant increase of specific antibodies, whereas a failure in the specific response in normal young subjects was observed, thus differences among the groups were no longer present. Moreover, the spectrotypic analysis of antibody response, by isoelectric focusing and reverse blotting, showed oligoclonal but polymorphic pattern in the majority of subjects, irrespective of the group, and more frequently lack of expansion of the spectrotype after vaccination, thus demonstrating the lack of the recruitment of antigen-specific B cells. Finally, the treatment with TP-5 did not influence the outcome of the vaccination in the group of elderly people. These results further emphasize the limited immunogenicity of influenza vaccination and the inefficacy of TP-5 as immunoadjuvant, in this model of vaccination.

Immunization of HIV-infected patients with rgp160: modulation of anti-rgp120 antibody spectrotype

HIV-1 infection results in progressive failure of the immune system with decline in the number and/or function of B-cell clones originally recruited in specific humoral responses. Spectrotypic analysis, done by isoelectric focusing and reverse blotting (IEF-RB), is one technique for evaluating the activity and the number of specific B-cell clones and is adaptable to the direct measurement of antibodies to conformationally intact epitopes. The anti-HIV-1 (IIIB) rgp120 spectrotype was measured in 30 early-stage HIV-infected volunteers undergoing vaccine therapy with recombinant gp160 (rgp160). Twenty-five of the patients displayed a clear oligoclonal banding pattern; seven (28%) showed the same pattern in all samples, while 18 (72%) showed changes. Ten of the latter had an increase in band intensity over the course of immunization, and eight had an increase in both band intensity and number of bands. In contrast, serum samples from eight patients receiving placebo (alum) showed no changes over a comparable period. These findings suggest that vaccine therapy with rgp160 may be able to expand the anti-HIV-1 (LAI) gp120 B-cell clone pool in some HIV-infected patients as well as increase antibody synthesis by established B-cell clones recruited during natural infection. These data provide further evidence that postinfection vaccination may provide an alternative strategy in the treatment of chronic viral diseases.

The role of complement in anti-bacterial defence

The complement system consists of several proteins present in human serum interacting among themselves and with the other compounds of the immune system in the host defence process. In particular, late complement component (C5, C6, C7, and C8) deficiencies (LCCD) are closely associated with Neisseria, mainly meningitidis, infections. The aim of our study was to verify this association in an Italian population by analyzing the complement profile in survivors of meningococcal meningitis. Ten out of the 59 (17%) subjects studied had homozygous LCCD (6 C8, 3 C7 and 1 C6). The meningococcal C strain was the most widely diffused (68%) and had infected all homozygous LCCD subjects. In addition meningococcal serogroup C seemed to be the least immunogenic when compared to serogroups A and B. These data confirm the close association between homozygous LCCD and meningococcal infections from common serogroups (A, B and C) in the Italian population. Anti-meningococcal vaccination is usually recommended for LCCD subjects because it increases, both quantitatively and qualitatively, the antibody component of anti-meningococcal immune defence. We therefore analyzed the levels of anti-polysaccharide (PS) A and PSC antibodies in the members of 4 families including normal subjects and subjects with homozygous and heterozygous C7, C8 or factor H defects, before and after vaccination with only PSA+C. Surprisingly, we found the highest levels of antibodies before vaccination in homozygous subjects, followed by heterozygous and normal controls, whereas, after vaccination, homozygous subjects showed the lowest increase of specific antibodies, indicating their relative incapacity to respond to meningococcal PS alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Lack of evidence for a superantigen in lymphocytes from HIV-discordant monozygotic twins

OBJECTIVE

An HIV-associated superantigen (SAg) has been hypothesized. Here we test whether an SAg is functionally detectable in peripheral blood mononuclear cells (PBMC) from monozygotic twins discordant for HIV infection.

DESIGN AND METHODS

The V beta selective T-cell depletion found in minor lymphocyte stimulation (Mls)-positive mice is caused by an SAg encoded by the mouse mammary tumour virus. Mls is a locus whose gene product stimulates a mixed lymphocyte reaction (MLR) in mice strains identical at the major histocompatibility complex locus. If an SAg is present in PBMC and/or sorted CD4+ cells from one HIV-infected monozygotic twin, it would stimulate PBMC from the corresponding healthy monozygotic twin in an MLR. In addition, if an SAg causes V beta-selective T-cell depletion in AIDS patients, a differential proliferation to a panel of staphylococcal enterotoxins (SE) of T lymphocytes from healthy and HIV-infected monozygotic twins should become measurable.

RESULTS

No positive MLR or significant differences in the SE-driven proliferation between the healthy and the HIV-infected twins were observed.

CONCLUSIONS

Our results suggest that PBMC from the two HIV-infected twins do not express a functionally detectable SAg.

Incidence of hepatitis A virus infection among an Italian military population

In 1990, a prospective serological survey to estimate the rate of clinical and inapparent infection with hepatitis A virus (HAV) was performed in a cohort of 1,268 soldiers, 18-24 years old, during an 8 month period in the Campania region in Italy. At the time of enrollment 318 (25%) of the 1,268 soldiers were positive for total antibodies to HAV (anti-HAV). None of them was positive for IgM anti-HAV. Among the 950 susceptible subjects who were followed up for 8 months, eight (0.8%) later seroconverted to anti-HAV positivity. This figure corresponds to an incidence of 1.3/100 person/years (eight seroconversions during 633.3 years of observation). There were two clinical (with presence of IgM-anti-HAV) and six inapparent infections. The clinical/subclinical HAV ratio was 1:3. These findings indicate that the risk of HAV infection among soldiers residing in this area is not negligible.

Evaluation of the overall degree of sensitization to airborne allergens by a single serologic test: implications for epidemiologic studies of allergy

In most epidemiologic studies of respiratory allergy, the overall degree of sensitization is usually measured by indices based on skin prick test reactions to a panel of relevant airborne allergens. In the present study we used a single assay (CAP-Phadiatop, Pharmacia, Uppsala, Sweden), which is based on the reaction between serum-specific IgE and a mixture of locally relevant inhalant allergens to measure the degree of sensitization to inhalants in the sera of 1815 young Italian men, in whom a complete diagnostic workup for respiratory allergy was performed in parallel. The intensity of reaction in the CAP-Phadiatop assay was highly correlated with: (1) an allergy index (p < 0.005), based on skin prick test reactivity to seven relevant inhalant allergens (Dermatophagoides pteronyssinus, mixed grass pollens, cat epithelium, Parietaria judaica, Olea europaea, Artemisia vulgaris, Alternaria tenuis); (2) the concentration of specific IgE to the same allergens, measured by CAP-RAST (p < 0.001), in both monosensitized and polysensitized subjects; (3) the rate of respiratory allergic diseases (p < 0.0001). Therefore CAP-Phadiatop intensity of reaction is a reliable indicator of the overall degree of sensitization to inhalant allergens. Furthermore, as demonstrated by relative operating characteristic analysis, it has an acceptable detectability power in identifying subjects with symptomatic expression of the atopy status [P(A) = 0.948]. The evaluation of the degree of sensitization to inhalants by a single and semiautomated assay represents a step forward in the standardization of procedures for epidemiologic studies of inhalant allergic diseases and for mass screening programs, which are aimed at identifying predictive markers of disease susceptibility.

Quantitative and qualitative analysis of anti-tetanus toxoid antibody response in the elderly. Humoral immune response enhancement by thymostimulin

In order to explore the humoral primary and secondary response to tetanus toxoid (TT), and to define the possible immunopotentiating effect of the thymic hormone thymostimulin, we studied 13 elderly people, selected according to the Senieur Eurage protocol, vaccinated against TT, an antigen never encountered before. Six of them were treated with thymostimulin before and during the immunization protocol. Specific anti-TT antibody level measurement and spectrotypic analysis were performed on the sera collected from the subjects at different times over the immunization protocol. In addition, spontaneous in vitro production of anti-TT antibodies as well as cutaneous delayed hypersensitivity reactions were also studied. Only one patient showed a detectable humoral immune response after the first immunization. After the booster, four of six thymostimulin-treated individuals, compared with only two of seven controls, showed in vivo anti-TT humoral response; at the same time, spontaneous anti-TT production was detected in peripheral blood mononuclear cells from five of six thymostimulin-treated individuals but only three of seven untreated controls. These differences were highly significant (p < 0.0001). In addition, only in thymostimulin-treated subjects were the levels of serum anti-TT antibodies 14, 21 and 28 days after the booster significantly (p < 0.05) higher than the baseline values. The spectrotypic analysis of anti-TT antibodies performed by isoelectric focusing and reverse blotting showed total agreement with the results from enzyme-linked immunosorbent assay.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibody response to meningococcal polysaccharides A and C in patients with complement defects

Patients with defects of terminal complement components are particularly exposed to the risk of developing neisserial infections and seem to respond poorly to meningococcal capsular polysaccharide (PS) C via natural immunization. The sole meningococcal PSC is, on the other hand, an excellent immunogen in normal people. Considering the great importance of vaccine prophylaxis for the prevention of meningococcal infections in patients with complement defects, it is crucial to study the antibody response to the sole meningococcal PS in these patients. We therefore analysed the levels of anti-PSA and PSC antibodies in the members of four families including patients with homozygous and heterozygous defects of C7, C8 or factor H, before and after vaccination with the sole PSA + C. Surprisingly, we found the highest levels of antibodies before vaccination in homozygous subjects, followed by heterozygous and normal controls, whereas, after vaccination, homozygous subjects showed the lowest increase of specific antibodies, indicating their relative incapability to respond to sole meningococcal PS. In conclusion, this study demonstrates (1) the capacity to respond to meningococcal PS via natural immunization by patients with total complement defects, and (2) the low responsiveness to meningococcal PS via vaccine immunization by the same patients. We propose that vaccination should be given to patients lacking specific antibodies and their serological response should be assessed. In addition this study confirms previous observations on a likely lower immunogenic power of meningococcal serogroup C via natural immunization compared with the better immunogenicity of the sole PSC.

Clinical and immunological response to typhoid vaccination with parenteral or oral vaccines in two groups of 30 recruits

The clinical and immunological responses to typhoid vaccination with parenteral and oral vaccines in two groups of 30 adult male subjects were studied. Specific anti-Salmonella typhi cell-mediated immunity and total or specific anti-lipopolysaccharide faecal immunoglobulin (Ig) A titres in vaccinated subjects were monitored. Cellular antibacterial activity was significantly increased only in orally vaccinated subjects. Serum arming activity and inhibition experiments suggested an IgA-dependent cellular cytotoxicity in those orally vaccinated. In these subjects, a total and anti-lipopolysaccharide faecal IgA increase was observed lasting up to 8 months after completion of the vaccination schedule. In parenteral vaccinated subjects, an early onset transitory increase of IgM rheumatoid factor was observed. Oral vaccine was well tolerated and free of side effects, whereas 65% of parenterally vaccinated subjects reported side effects such as fever, headache, malaise and local tenderness in the injection site.

Dramatic reduction of meningococcal meningitis among military recruits in Italy after introduction of specific vaccination

Meningococcal meningitis is still a serious infectious disease with a mortality rate that can be as high as 10% even in developed countries. Military recruits are generally a high-risk group for meningococcal disease, with a reported incidence of four to ten times greater than that of the general population. In Italy the results of the National Meningitis Surveillance Programme showed a high attack rate of the disease among recruits in 1985 as well as in 1986, with 92 and 95% of the cases, respectively, caused by serogroup C and thus preventable. These findings led to the authorities' decision to make vaccination against meningococcal disease mandatory for recruits starting from January 1987. After almost 5 years from the introduction of meningococcal vaccination, we here sum up the epidemiological and immunological effects of the vaccination. From the epidemiological point of view we have observed a dramatic reduction of the prevalence of the disease. In 1987, the year in which we had 150,000 unvaccinated and 150,000 vaccinated recruits, the protective efficacy was 91.2%. From the immunological point of view, vaccination is highly effective, as seroconversion against polysaccharide (PS) A and C is 84 and 91%, respectively. The spectrotypic analysis of the sera before and after vaccination shows that the type of response is mainly oligoclonal, like the majority of the responses to PSs, and the antibodies induced by a sole PS are not qualitatively different from the antibodies induced by natural immunization. In addition, the efficacy is not modified by environmental factors like hypoxia, as demonstrated during permanence at 16,174 feet for 20 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of stress on lymphocyte subset distribution--a flow cytometric study in young student pilots

Stressors can induce sizable modifications on immunocompetent cells. Major circulating lymphocyte subsets were quantitated in Italian Air Force student pilots undergoing intensive training and continuous evaluation, a stressful situation both physically and psychologically. Instructor pilots matched for age and assayed in parallel were used as controls. A typical flight training session was not able per se to induce immediate significant modifications of the lymphocyte subset distribution either in the students or instructors, although it did affect plasma levels of stress-related hormones such as growth hormone, prolactin and cortisol in the former. Irrespective of the time of flying, however, the percentage of CD4+ lymphocytes and the CD4/CD8 ratio were lower in students than in instructors, and the absolute number of CD8+ lymphocytes was higher in students than in instructors. In a second series of experiments, 30 student pilots were tested at the beginning and at the end of a flight course (duration 30 days). Although the percentage of CD29+ lymphocytes comprised in the CD8+ subset was reduced at the end of the course in all individuals, such a reduction was more evident in those students who failed to pass the final examination, an additional cause of psychological stress. In light of the functional significance of the lymphocyte subsets investigated, it is suggested that the present stress-induced alterations may have practical implications.

Tetanus immunity among Italians born after the introduction of mandatory vaccination of children

In Italy systematic mandatory tetanus immunization of children started in 1968. In a national sample of 241 young males born after 1968 the prevalence of non-immune subjects was 11.2% (5.5% in the North-Centre, 15.9% in the South-Islands; p < 0.02). Comparing these data with the corresponding figure obtained in a previous study of subjects born before 1968 a significant decrease (11.2% versus 32.6%; p < 0.01) is observed. The prevalence of non-immune subjects born after 1968 is significantly (p < 0.01) lower than that observed in subjects born before 1968 by geographical area as well as by area (urban/rural) of residence. These findings indicate that the introduction of compulsory tetanus vaccination for all newborns has favourably affected the immune status of younger Italian men. However, more efforts should still be addressed to decrease regional inequalities in the delivery of health care.

Presentation of superantigen by human T cell clones: A model of T-T cell interaction

Superantigens (SAg) interact with T lymphocytes bearing particular V beta sequences as part of their T cell receptor (TcR). The interaction, however, requires the presence of major histocompatibility complex (MHC) class II molecules on antigen-presenting cell (APC). In peculiar circumstances, MHC class II+ T cell clones (TCC) have been shown to present peptides and selected antigens interacting with antigen-specific TCC in the absence of APC. In this report we studied the capacity of SAg to mediate a T-T cell interaction, investigating the TCC ability to present a panel of staphylococcal enteroxins (SE) independently of the presence of added APC. Upon exposure to a broad range of SE concentrations, MHC class II+ TCC showed an intense proliferative response even in the absence of professional APC. Diverse SE optimally stimulated responder TCC at different concentrations. The proliferation was inhibited by anti-DR monoclonal antibodies, both in the presence and in the absence of APC. The SE activation of TCC in the absence of APC induced the same series of phenotypic variations as that observed following the TCC stimulation with APC. Irradiated TCC efficiently presented membrane-bound SE to responder TCC as well as professional APC. These results show that a single cell of a given clone effectively presents the SE to other cells of the same clone, and provide evidence that SAg can efficiently mediate T-T cell interaction. In addition, the possibility also exists that one cell of the clone can actually undergo an auto-stimulation via SAg-mediated interactions between its own TcR and MHC class II molecule. It has recently been suggested that the V beta-selective depletion of T cells observed in acquired immunodeficiency syndrome (AIDS) patients might be a consequence of the interaction between a human immunodeficiency virus (HIV)-encoded SAg and T cells expressing a SAg complementary V beta. We suggest that the hypothesized HIV-encoded SAg might mediate T-T cell interactions that could play a relevant role in the V beta-selective depletion of T lymphocytes observed in HIV-infected patients.