Evaluation of in vitro SARS-CoV-2 inactivation by a new quaternary ammonium compound: Bromiphen bromide

The pneumonia (COVID-19) outbreak caused by the novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which unpredictably exploded in late December of 2019 has stressed the importance of being able to control potential pathogens with the aim of limiting their spread. Although vaccines are well known as a powerful tool for ensuring public health and controlling the pandemic, disinfection and hygiene habits remain crucial to prevent infection from spreading and maintain the barrier, especially when the microorganism can persist and survive on textiles, surfaces, and medical devices. During the coronavirus disease pandemic, around half of the disinfectants authorized by the US Environmental Protection Agency contained quaternary ammonium compounds (QACs); their effectiveness had not been proven. Herein, the in vitro SARS-CoV-2 inactivation by p-bromodomiphen bromide, namely bromiphen (BRO), a new, potent, and fast-acting QAC is reported. This study demonstrates that BRO, with a dose as low as 0.02%, can completely inhibit SARS-CoV-2 replication in just 30 s. Its virucidal activity was 10- and 100-fold more robust compared to other commercially available QACs, namely domiphen bromide and benzalkonium chloride. The critical micellar concentration and the molecular lipophilicity potential surface area support the relevance of the lipophilic nature of these molecules for their activity.

The pathophysiological role of estrogens in the initial stages of pregnancy: molecular mechanisms and clinical implications for pregnancy outcome from the periconceptional period to end of the first trimester

BACKGROUND

Estrogens regulate disparate female physiological processes, thus ensuring reproduction. Altered estrogen levels and signaling have been associated with increased risks of pregnancy failure and complications, including hypertensive disorders and low birthweight babies. However, the role of estrogens in the periconceptional period and early pregnancy is still understudied.

OBJECTIVE AND RATIONALE

This review aims to summarize the current evidence on the role of maternal estrogens during the periconceptional period and the first trimester of pregnancies conceived naturally and following ART. Detailed molecular mechanisms and related clinical impacts are extensively described.

SEARCH METHODS

Data for this narrative review were independently identified by seven researchers on Pubmed and Embase databases. The following keywords were selected: 'estrogens' OR 'estrogen level(s)' OR 'serum estradiol' OR 'estradiol/estrogen concentration', AND 'early pregnancy' OR 'first trimester of pregnancy' OR 'preconceptional period' OR 'ART' OR 'In Vitro Fertilization (IVF)' OR 'Embryo Transfer' OR 'Frozen Embryo Transfer' OR 'oocyte donation' OR 'egg donation' OR 'miscarriage' OR 'pregnancy outcome' OR 'endometrium'.

OUTCOMES

During the periconceptional period (defined here as the critical time window starting 1 month before conception), estrogens play a crucial role in endometrial receptivity, through the activation of paracrine/autocrine signaling. A derailed estrogenic milieu within this period seems to be detrimental both in natural and ART-conceived pregnancies. Low estrogen levels are associated with non-conception cycles in natural pregnancies. On the other hand, excessive supraphysiologic estrogen concentrations at time of the LH peak correlate with lower live birth rates and higher risks of pregnancy complications. In early pregnancy, estrogen plays a massive role in placentation mainly by modulating angiogenic factor expression-and in the development of an immune-tolerant uterine micro-environment by remodeling the function of uterine natural killer and T-helper cells. Lower estrogen levels are thought to trigger abnormal placentation in naturally conceived pregnancies, whereas an estrogen excess seems to worsen pregnancy development and outcomes.

WIDER IMPLICATIONS

Most current evidence available endorses a relation between periconceptional and first trimester estrogen levels and pregnancy outcomes, further depicting an optimal concentration range to optimize pregnancy success. However, how estrogens co-operate with other factors in order to maintain a fine balance between local tolerance towards the developing fetus and immune responses to pathogens remains elusive. Further studies are highly warranted, also aiming to identify the determinants of estrogen response and biomarkers for personalized estrogen administration regimens in ART.

SARS-CoV-2 mRNA vaccine BNT162b2 triggers a consistent cross-variant humoral and cellular response

As the SARS-CoV-2 pandemic continues to rage worldwide, the emergence of numerous variants of concern (VOC) represents a challenge for the vaccinal protective efficacy and the reliability of commercially available high-throughput immunoassays. Our study demonstrates the administration of two doses of the BNT162b2 vaccine that elicited a robust SARS-CoV-2-specific immune response which was assessed up to 3 months after full vaccination in a cohort of 37 health care workers (HCWs). SARS-CoV-2-specific antibody response, evaluated by four commercially available chemiluminescence immunoassays (CLIA), was qualitatively consistent with the results provided by the gold-standard in vitro neutralization assay (NTA). However, we could not observe a correlation between the quantity of the antibody detected by CLIA assays and their neutralizing activity tested by NTA. Almost all subjects developed a SARS-CoV-2-specific T-cell response. Moreover, vaccinated HCWs developed a similar protective neutralizing antibodies response against the EU (B.1), Alpha (B.1.1.7), Gamma (P.1), and Eta (B.1.525) SARS-CoV-2 variants, while Beta (B.1.351) and Delta (B.1.617.2) strains displayed a consistent partial immune evasion. These results underline the importance of a solid vaccine-elicited immune response and a robust antibody titre. We believe that these relevant results should be taken into consideration in the definition of future vaccinal strategies.

Lung Allograft Dysfunction in a COVID-19 Transplanted Patient is Associated with a Peculiar Immunopathological Phenotype

Purpose

Lung transplantation (LT) after severe SARS-CoV-2 infection is emerging as a life-saving medical procedure for selected patients who experience acute respiratory distress syndrome (ARDS). We present the first immunopathological evaluation of a lung allograft rejection in a patient who underwent LT because of irreversible ARDS related to COVID-19.

Methods

Two male patients with irreversible ARDS caused by COVID-19 underwent bilateral LT at our Institution. A surveillance transbronchial biopsy (TBB) was performed 2 months after LT in the first patient (Pt#1), while the second patient (Pt#2) died because of allograft rejection at day 62 post LT and explanted lungs were retrieved. CT imaging of the lungs was performed three days before death. Morphological examination was performed by H&E, whereas the immunophenotyping was performed by immunohistochemistry.

Results

Imaging and morphological examination of Pt#2 lungs indicated the presence of a graft dysfunction with features of a restrictive, widespread usual interstitial pneumonia-like syndrome (Fig. 1A, B). The immunophenotyping showed that B-lymphocytes (CD20-positive) were nearly absent, CD8-T-cells were not particularly expanded (mean positive cells within the lung stroma=13.8%; Fig. 1C), and the CD4/CD8 ratio was not decreased (Fig. 1D). The T-regs (Foxp3-positive) were 6% of the overall population (Fig. 1E). Analysis of the immune checkpoint molecules PD1, Tigit, CTLA4 and PDL1 showed that the expression of PD-L1 alone was highly increased in vases and in alveolar cells of rejected lungs, whereas it was nearly undetectable in the TBB from Pt#1 (Fig. 1F, G).

Conclusion

PDL1 expression in vases was previously documented as a sign of indirect ARDS. Together with our preliminary data, we can hypothesize that PDL1 may play a role in tissue effacement and graft failure, possibly indicating poor allograft prognosis.

Upregulation of inflammasome activity and increased gut permeability are associated with obesity in children and adolescents

BACKGROUND

Immune activation contributes to the persistent state of inflammation associated with metabolic dysfunction in obesity. The specific immune receptors that sense metabolic stress signals and trigger inflammation are nevertheless largely unknown, and little is known on inflammatory and immune gene regulation in obesity.

METHODS

The study includes a cross-sectional and a longitudinal arm. Forty children and adolescents were enrolled: 22 obese subjects and 18 age-matched normal weight controls. Obese subjects participated in an 18-month therapeutic protocol, based on intensive lifestyle modification (dietary regimen, physical activity and behavioral interventions). Expression of genes involved in the inflammasome pathway, plasma concentration of the inflammasome-associated pro-inflammatory cytokines (interleukin (IL)-1β and IL-18) and indexes of microbial translocation (lipopolysaccharide (LPS), soluble CD14 (sCD14) and intestinal fatty acid-binding protein) were analyzed at baseline in obese subjects compared with controls, and after 18 months in obese subjects.

RESULTS

Cross-sectional analyses showed that the LPS-induced expression of genes involved in inflammasome (NLRP3, caspase 5 and NAIP), Nod-like receptors (NLRX1 and NOD1), downstream signaling (P2RX7, RAGE, RIPk2, TIRAP and BIRC2) and effector molecules (IFN-γ, IL-12β, IL-1β, CCL2, CCL5, IL-6 and TNFα) was significantly increased in obese subjects at baseline as compared with normal weight controls. The baseline plasma concentration of inflammasome-related cytokines (IL-1β and IL-18) and of microbial translocation markers (LPS and sCD14) was augmented in obese subjects as compared with controls as well. Longitudinal analyses indicated that intensive lifestyle modification resulted in a normalization of parameters in subjects with a significant reduction of BMI after 18 months.

CONCLUSIONS

In children and adolescents, obesity is characterized by the activation of the inflammasome and by an alteration of gut permeability. Successful lifestyle modification is effective in reducing inflammation, suggesting that inhibition of the inflammasome may be a potential therapeutic strategy in obesity.

Association of complement receptor 2 polymorphisms with innate resistance to HIV-1 infection

HIV-1 induces activation of complement through the classical and lectin pathways. However, the virus incorporates several membrane-bound or soluble regulators of complement activation (RCA) that inactivate complement. HIV-1 can also use the complement receptors (CRs) for complement-mediated antibody-dependent enhancement of infection (Ć-ADE). We hypothesize that hypofunctional polymorphisms in RCA or CRs may protect from HIV-1 infection. For this purpose, 139 SNPs located in 19 RCA and CRs genes were genotyped in a population of 201 Spanish HIV-1-exposed seronegative individuals (HESN) and 250 HIV-1-infected patients. Two SNPs were associated with infection susceptibility, rs1567190 in CR2 (odds ratio (OR) = 2.27, P = 1 × 10(-4)) and rs2842704 in C4BPA (OR = 2.11, P = 2 × 10(-4)). To replicate this finding, we analyzed a cohort of Italian, sexually HESN individuals. Although not significant (P = 0.25, OR = 1.57), similar genotypic proportions were obtained for the CR2 marker rs1567190. The results of the two association analyses were combined through a random effect meta-analysis, with a significant P-value of 2.6 x 10(-5) (OR = 2.07). Furthermore, we found that the protective CR2 genotype is correlated with lower levels CR2 mRNA as well as differences in the ratio of the long and short CR2 isoforms.

Immunomodulating activity of Pidotimod in children with Down syndrome

Acute respiratory tract infections (ARTIs) are the most frequent illnesses in pediatric age, frequently experienced in children with Down Syndrome (DS) due to the associated immune defects of both specific and non-specific immunity. Pidotimod, a synthetic immunostimulant, was shown to reduce the rates of ARTIs in children with DS, however the mechanisms associated with this effect is currently unknown. We analyzed immune parameters in DS children who received the seasonal 2011–2012 virosomal-adjuvanted influenza vaccine. Eighteen children aged 3-10 years (mean age 7.1+/-2.6 years) were randomly assigned (1:1 ratio) to receive Pidotimod 400 mg, administered orally once a day for 90 days or placebo. At the recruitment (T0) all children received a single dose of virosomal-adjuvanted influenza vaccine (Flu). Blood samples were collected at T0 and 3 months after the recruitment (T3) in order to evaluate innate and adaptative immune responses pathway. Flu-specific IgG1 and IgG3 levels in plasma samples were determined at pre-vaccination (T0), and 1 (T1) and 3 months (T3) post-vaccination. The use of Pidotimod was associated with the upregulation of a number of genes involved in the activation of innate immune responses and in antimicrobial activity. Interestingly the ratio of Flu-specific IgG1/IgG3 was skewed in pidotimod-treated individuals, suggesting a preferential activation of complement-dependent effector mechanisms. Although preliminary these data suggest that Pidotimod can potentiate the beneficial effect of immunization, possibly resulting in a stronger activity of both innate and adaptive immune responses.

Long-term balancing selection maintains trans-specific polymorphisms in the human TRIM5 gene

The human TRIM5 genes encodes a retroviral restriction factor (TRIM5α). Evolutionary analyses of this gene in mammals have revealed a complex and multifaceted scenario, suggesting that TRIM5 has been the target of exceptionally strong selective pressures, possibly exerted by recurrent waves of retroviral infections. TRIM5 displays inter-individual expression variability in humans and high levels of TRIM5 mRNA have been associated with a reduced risk of HIV-1 infection. We resequenced TRIM5 in chimpanzees and identified two polymorphisms in intron 1 that are shared with humans. Analysis of the gene region encompassing the two trans-specific variants in human populations identified exceptional nucleotide diversity levels and an excess of polymorphism compared to fixed divergence. Most tests rejected the null hypothesis of neutral evolution for this region and haplotype analysis revealed the presence of two deeply separated clades. Calculation of the time to the most recent common ancestor (TMRCA) for TRIM5 haplotypes yielded estimates ranging between 4 and 7 million years. Overall, these data indicate that long-term balancing selection, an extremely rare process outside MHC genes, has maintained trans-specific polymorphisms in the first intron of TRIM5. Bioinformatic analyses indicated that variants in intron 1 may affect transcription factor-binding sites and, therefore, TRIM5 transcriptional activity. Data herein confirm an extremely complex evolutionary history of TRIM5 genes in primates and open the possibility that regulatory variants in the gene modulate the susceptibility to HIV-1.

Genetic correlates of protection against HIV infection: the ally within

Repeated exposure to HIV does not necessarily result in infection and HIV infection does not inevitably lead to the development of the AIDS. Multiple immunological and genetic features can confer resistance to HIV acquisition and progression at different steps in viral infection; a full understanding of these mechanisms could result in the development of novel therapeutic and vaccine approaches for HIV infection. In this review, we focus on the genetic mechanisms associated with resistance to HIV infection and to the progression to AIDS.

Functional analysis of HIV-specific cytotoxic T lymphocytes in antiviral-treated- and-naive patients: a preliminary report

HIV-specific CTL functions were analyzed in HIV-infected individuals who did or did not receive antiretroviral therapy (ART). Results showed that gp 160 (env)-stimulated perforin- and granzyme-expressing CTL, as well as perforin and granzyme-specific mRNA, were reduced in treated patients whereas TNFalpha was increased in ART-treated compared to naive individuals. Reduction of perforin and granzyme-expressing cells was not secondary to impaired IFNgamma production. A defect of CTL is observed in ART-treated individuals; this defect is not dependent on impaired Th cell function. These results reinforce the need for immunomodulants to successfully approach therapy of HIV infection.

Mucosal and systemic immune activation is present in human immunodeficiency virus-exposed seronegative women

Immune parameters were analyzed in peripheral blood mononuclear cells (PBMC) and cervical mucosa biopsy specimens of human immunodeficiency virus (HIV)-seronegative women sexually exposed to HIV (exposed seronegative [ESN]), HIV-infected women, and healthy women without HIV exposure. HIV was not detected in PBMC or cervical mucosa biopsy specimens of ESN women. However, interleukin (IL)-6, IL-10, IL-12, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha and -beta mRNA were elevated in PBMC and cervical mucosa biopsy specimens of ESN and HIV-infected women; CCR5 and CXCR4 mRNA were augmented in cervical mucosa biopsy specimens, but not in PBMC, of ESN and HIV-infected women; HIV-specific IFN-gamma-secreting cells were detected in vaginal washes of ESN and HIV-infected women; and phenotypic alterations were present in PBMC of ESN women. These results suggest that active HIV infection is not required for T cell activation; immune alterations occur in women in whom HIV infection cannot be detected virologically or clinically.

Different immunologic profiles characterize HIV infection in highly active antiretroviral therapy-treated and antiretroviral-naïve patients with undetectable viraemia. The Master Group

BACKGROUND

Suppression of human immunodeficiency virus (HIV) replication can be obtained in chronically infected individuals by highly active antiretroviral therapy (HAART) and can also be observed in antiretroviral-naïve patients. The immunological correlates of these two situations were examined.

DESIGN AND METHODS

Cross-sectional study involving 32 HIV-infected patients with undetectable HIV plasma viraemia (< 500 copies/ml) and either antiretroviral-naive (n = 14) or undergoing HAART therapy with two nucleoside reverse transcriptase inhibitors (NRTI) plus one (n = 13) or two (n = 5) protease inhibitors (PI). CD4 counts, disease duration, and CDC clinical stage were comparable between the two groups of individuals. Immune parameters (antigen- and mitogen-stimulated proliferation and cytokine production; cytokine mRNA; beta chemokine production; HIV coreceptors mRNA) were analysed in all patients.

RESULTS

Results showed immune profiles to be profoundly different in antiretroviral-naive in comparison with HAART-treated patients. Thus: (1) T-cell proliferation to HIV-specific and HIV-unrelated antigens is potent in antiretroviral-naive but suppressed in HAART-treated individuals; (2) interleukin-(IL)2, IL-12 and interferon gamma (IFNgamma) production is robust in naive patients; and (3) a high CCR5/low CXCR4 pattern of HIV coreceptors-specific mRNA is observed in naive but not in HAART-treated patients. In contrast with these observations, no clear differences were detected when beta chemokine production by either peripheral blood mononuclear cells or purified CD8+ T-cells was analysed. Results from HAART-treated patients undergoing therapy with one PI and two NRTI or two PI and two NRTI were in very close agreement.

CONCLUSIONS

These data suggest that control over HIV replication can be independently achieved by pharmacological or immunologic means. HAART is associated with weaker HIV-specific and -non-specific immune responses.

Human immunodeficiency virus (HIV)-specific IgA and HIV neutralizing activity in the serum of exposed seronegative partners of HIV-seropositive persons

The presence and activity of human immunodeficiency virus (HIV)-specific antibodies were analyzed in the sera of 15 sexually exposed seronegative persons who had systemic HIV-specific cell-mediated immunity and IgA-mediated mucosal immunity and in their HIV-infected partners. The HIV-positive subjects had HIV-specific serum IgG and IgA; the seronegative persons had HIV-specific serum IgA in the absence of IgG. Testing of the seronegative persons 1 year after the interruption of at-risk sex showed that no IgG seroconversion had occurred and that HIV-specific IgA serum concentrations had declined. Serum from the HIV-exposed seronegative persons was analyzed for the ability to neutralize primary HIV-1 isolates. Neutralizing activity was detected in 5 of 15 sera and in 2 cases was retained by serum-purified IgA. Thus, the immunologic picture for resistance to HIV infection should include HIV-specific cell-mediated immunity as well as HIV-specific IgA-mediated mucosal and systemic immunity.

Altered signaling lymphocytic activation molecule (SLAM) expression in HIV infection and redirection of HIV-specific responses via SLAM triggering

Signaling lymphocytic activation molecule (SLAM) is a transmembrane lymphocytic receptor which gets rapidly upregulated following cell activation. SLAM engagement augments T cell expansion and interferon-gamma (IFN-gamma) production independently of CD28. SLAM signaling is regulated by the SLAM-associated protein. We evaluated the expression and function of SLAM on CD4(+) and CD8(+) lymphocytes in HIV-infected individuals with either recently acquired infection (Group A) or asymptomatic HIV infection (Group B) and in healthy controls (HC). Soluble antigen (HIV env peptides and tetanus toxoid)- and mitogen-stimulated proliferation and IFN-gamma and IL-10 production upon SLAM costimulation were also measured. Results showed that: (1) SLAM-expressing CD4(+) and CD8(+) lymphocytes diminish in group A patients compared to both group B patients and HC; (2) SLAM expression on CD4(+) lymphocytes is preferentially associated with the lack of CD7 on cell surface (CD4(+)CD7(-) produce IL-10 but not IFN-gamma); (3) SLAM engagement increases HIV env peptide-stimulated, but neither tetanus toxoid- nor PHA-stimulated proliferation of peripheral blood mononuclear cells (PBMC) in patients but not in HC; and (4) SLAM engagement augments IFN-gamma and reduces IL-10 production by env peptide-stimulated PBMC of HIV-infected individuals. These results demonstrate that early HIV infection results in an altered SLAM expression which correlates with a time-limited impairment of cell-mediated immunity. Furthermore, they show that triggering via SLAM potentiates HIV-specific proliferative responses with simultaneous downregulation of IL-10 and redirection of the response to TH0/TH1.

A role for mucosal immunity in resistance to HIV infection

In a recent, thought-provoking novel by Elizabeth McCracken (The Giant's House. Avon Books, New York, 1997), two characters discuss love and its impossibilities. One brashly claims to be "immune to love", explaining the concept to his perplexed interlocutor, "...people become immune to love like they become immune to any disease. Either they had it bad early in life, like chicken pox and that's that; or they keep getting exposed to it in little doses and build up an immunity; or somehow they just don't catch it, something in'em is born resistant. I'm the last type. I'm immune to love and poison ivy". (p. 275) (E. McCracken, The Giant's House. Avon Books, New York, 1997). Substitute the words 'HIV infection' for 'love' and this intriguing metaphor summarizes the state of the art working hypotheses for the phenomenon of resistance to HIV infection in HIV-exposed individuals who, against all odds, do not seroconvert. These hypotheses will be discussed hereafter and particular emphasis will be placed upon a possible role for mucosal immunity in this phenomenon.

Cytokine production and surface marker expression in acute and stable multiple sclerosis: altered IL-12 production and augmented signaling lymphocytic activation molecule (SLAM)-expressing lymphocytes in acute multiple sclerosis

Ag-stimulated IL-2 production and mitogen-stimulated type 1 and type 2 cytokine production by PBMC, as well as expression of Th1- and Th2-associated phenotypical markers, of B7-1, B7-2, and CD95 (Fas) on the surface of immune cells, and the serum concentration of soluble Apo-1/Fas were evaluated in multiple sclerosis (MS) patients with either acute (AMS) or stable (SMS) disease and in healthy controls (HC). Results showed that 1) Ag-stimulated IL-2 production is reduced in MS patients compared with that in HC; 2) mitogen-stimulated type 1 cytokine production is increased, and IL-10 production is reduced in MS patients compared with those in HC, and in AMS patients compared with those in SMS; 3) whereas production of the metabolically active p70 heterodimers is comparable in SMS, AMS, and HC, production of the p70 heterodimer and the p40 chains (total IL-12) is increased in SMS compared with that in AMS and HC; 4) CD4+, CD4+ SLAM+, and CD4+ CD7+ lymphocytes (preferentially type 1 cytokine-producing lymphocytes) are increased in MS compared with levels in HC; 5) B7-2- as well as Fas+-expressing monocytes are augmented in MS compared with those in HC, and serum soluble Apo-1/Fas is augmented in AMS compared with SMS and HC. These results confirm that a complex imbalance in both cytokine production and the Fas system is present in MS and indicate that different cytokine profiles may be observed in patients with acute or stable disease. The data also suggest that peculiar phenotypic populations are over-represented in MS patients, and for the first time show that SLAM expression is correlated with dysregulation of type 1 and type 2 cytokine production in human pathology.

HIV-specific mucosal and cellular immunity in HIV-seronegative partners of HIV-seropositive individuals

HIV-specific mucosal and cellular immunity was analyzed in heterosexual couples discordant for HIV status in serum and in HIV-unexposed controls. HIV-specific IgA but not IgG was present in urine and vaginal wash samples from HIV-exposed seronegative individuals (ESN), whereas both IgA and IgG were observed in their HIV-seropositive partners; antibodies were not detected in low-risk controls. Envelope protein (Env) peptide-stimulated interleukin-2 (IL-2) production by peripheral blood mononuclear cells (PBMCs) was detected in 9 out of 16 ESNs, 5 out of 16 HIV-infected patients and 1 out of 50 controls. Env peptide-stimulated PBMCs of ESNs produced more IL-2 and less IL-10 compared with those of HIV-infected individuals; no differences were observed in chemokine production or in CCR5 expression. These data demonstrate that a compartmentalized immune response to pathogens is possible in humans and raise the possibility of protective roles for cell-mediated immunity and mucosal IgA in HIV-seronegative individuals exposed to HIV.

Type 1 and type 2 cytokines in HIV infection -- a possible role in apoptosis and disease progression

The progression of HIV-infected subjects to AIDS was recently postulated to be controlled by the balance between type 1 cytokines (mainly enhancing cell-mediated immunity) and type 2 cytokines (mainly augmenting antibody production). Thus, progression of HIV infection was suggested to be accompanied by a decline of in vitro production of interleukin-2 (IL-2), IL-12 and interferon gamma (IFN-gamma) (type 1 cytokines) and an increase in the production of IL-4, IL-5, IL-6 and IL-10 (type 2 cytokines) by peripheral blood mononuclear cells of HIV-seropositive patients. According to this hypothesis, clinical markers of progression would be considered the loss of the ability to elicit a delayed-type hypersensitivity reaction to ubiquitous antigens (secondary to defective IL-2 production), hyper-IgE (secondary to increased IL-4 production) and hypereosynophilia (secondary to increased IL-5 production). The type 1 to type 2 shift was suggested to be predictive for the following events: (i) reduction in CD4 counts; (ii) time to AIDS diagnosis; (iii) time to death. Support for this hypothesis stems from the recent observation that a strong type 1/weak type 2 cytokine production profile was observed in HIV-seropositive patients with delayed or absent disease progression, whereas progression of HIV infection was characterized by a weak type 1/strong type 2 cytokine production profile. PBMC of HIV-seropositive individuals are susceptible to antigen-induced cell death (AICD) after antigen recognition via T-cell receptor (TcR). While TcR-induced AICD is seen in CD4+ and CD8+ cells programmed cell death induced by recall antigens is preferentially observed in CD4+ cells, a situation more closely resembling the CD4 depletion of HIV infection. Because type 1 cytokines reduce, whereas type 2 cytokines augment T-lymphocyte AICD, an increase in the concentration of type 2 cytokines could result in the decline in CD4+ cells seen in HIV infection.

Prognostic value of proliferating cell nuclear antigen (PCNA) expression in unresectable hepatocellular carcinoma

Recent studies indicate that evaluation of cell proliferation in mallignant tumors may have prognostic value, but limited data are available on its expression in hepatocellular carcinoma. We therefore evaluated the prognostic tool of PCNA antigen expression on paraffin-embedded sections of 54 patients with hepatocellular carcinoma and concomitant cirrhosis. According to the number of positive cells, the PCNA expression ranged between 0.8 and 47%, and was divided into two groups (Group A, PCNA less than or equal to 5.5%; Group B, PCNA >5.5%). The two groups of patients were numerically well balanced. Median survival was 16 months for group A and 12 months for group B. According to the Cox multivariate analysis, PCNA expression (P=0.002),TNM stage (P=0.009) and ECOG performance status (P<0.001) significantly correlated with survival. In conclusion, PCNA antigen expression was found to be a significant prognostic faeature in unresectable hepatocellular carcinoma and may be a useful tool for future trials.