HIV-1: towards understanding the nature and quantifying the latent reservoir

The human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) pandemic constitutes one of the greatest public health issues, since 36.9 million people worldwide were living with HIV in 2017 and 940,000 died from AIDS- related illnesses in the same year. One of the main obstacles in the effort to achieve viral eradication or long-term virologic remission is the existence of the HIV-reservoir. Except for resting memory CD4+ T cells there is a plethora of innate immunity cells including macrophages, dendritic cells, follicular T helper cells and NK cells which are now considered to play a role in viral latency and persistence. Hematopoietic precursor cells and progenitor mast cells, astrocytes, fibrocytes, renal and liver epithelial cells could also contribute to the reservoir, but their role remains controversial. Tissue reservoirs, such as the central nervous system (CNS), lymphoid tissue, adipose tissue and the gut-associated-lymphoid-tissue (GALT) are usually referred to as anatomic sanctuaries, where it is difficult to achieve high concentration and efficacy of antiretroviral agents. Accurate quantification of this reservoir is of the utmost importance and multiple assays have been developed for this purpose. The role of several cell populations in viral latency needs to be clarified by further studies. Furthermore, there is an urgent need for new assays, which will accurately measure the size of the reservoir, which plays a key role in predicting the timing of viral rebound upon cessation of antiretroviral treatment, since the currently available ones either overestimate or underestimate the size and have significant limitations. Keywords: HIV-1; cellular reservoirs; tissue reservoirs; quantification.

Thrombophilic gene polymorphisms and recurrent pregnancy loss in Greek women

INTRODUCTION

Recurrent pregnancy loss (RPL) is a multifactorial disorder. The aim of this study was the detection of various genetic polymorphisms and their correlation to RPL, in Greek women.

METHODS

The impact of 12 thrombophilic polymorphisms was evaluated, among 48 Greek women with a history of RPL, vs 27 healthy parous women. Multiplex PCR and in situ hybridization on nitrocellulose films were performed, to investigate 12 genetic polymorphisms previously reported as risk factors for RPL.

RESULTS

Heterozygous FV Leiden, homozygous PAI-1 4G/4G, heterozygous MTHFR C677T, homozygous MTHFR A1298C, as much as the combined thrombophilic genotypes MTHFR 677T + ACE Ι/D, MTHFR 677T/1298C + ACE D/D, ACE I/D + b-fibrinogen -455 G/A, FV HR2 + b-fibrinogen -455 G/A showed a correlation as risk factors for RPL, whereas the rest of the investigated polymorphisms and their combinations did not render statistically significant differences between the two groups in study.

CONCLUSION

The results of this study, as well as those of similar studies, concerning the detection of genetic, environmental, and physiological factors underlying RPL, will prove of critical significance in the investigation and treatment of thrombophilic predisposition, in cases of RPL.

West Nile virus meningitis in a patient with human immunodeficiency virus type 1 infection

The emergence of West Nile virus lineage 2 in central Macedonia, Greece, in 2010 resulted in large outbreaks for 5 consecutive years. We report a case of viral meningitis in an individual infected with human immunodeficiency virus type 1, which preceded the recognition of the outbreak and was confirmed retrospectively as West Nile virus neuroinvasive disease.

Double- and multi-carbapenemase-producers: the excessively armored bacilli of the current decade

Multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative nosocomial pathogens commonly carry one carbapenemase gene conferring resistance to carbapenems and other beta-lactam antibiotics. However, increasing reports show that double-carbapenemase-producing (DCP) and even multi-carbapenemase-producing (MCP) bacteria are emerging in some parts of the world, diminishing further, in some cases, the already limited treatment options. In the present review, the up-to-date reports of DCP and MCP isolates are summarized and concerns regarding their emergence are discussed.

Detection and typing of human papillomaviruses (HPV) in malignant, dysplastic, nondysplastic and normal oral epithelium by nested polymerase chain reaction, immunohistochemistry and transitional electron microscopy in patients of northern Greece

OBJECTIVES

To evaluate the role of HPV in oral carcinogenesis, we examined the prevalence of HPV in malignant, potentially malignant and normal oral epithelium and studied the relation of HPV prevalence with other factors obtained from the patient's records.

MATERIALS AND METHODS

Our material consisted of 291 tissue specimens from 258 individuals. From every individual formalin fixed and paraffin embedded tissues were examined by nested Polymerase Chain Reaction (NPCR) for the detection of HPV DNA and by immunohistochemistry (IHC) for the in situ detection of HPV L1 protein. Positive PCR products were sequenced in order to type HPVs. Also 33 fresh tissues were obtained, fixed and used to detect HPV particles by transitional electron microscopy (TEM).

RESULTS

HPV was detected in 32.9% of the tissue specimens by NPCR, in 4.7% by immunohistochemistry and in 28.1% by TEM. In detail, by nested PCR HPV L1 DNA was detected in 40% of normal tissues, 40% of fibromas, 35.8% of non-dysplastic leukoplakias, 31.6% of dysplastic leukoplakias and 22.2% of oral squamous cell carcinomas. The HPV viral load of 96.5% of the samples was very low (1 viral copy per 10(2)-10(4) cells). HPV16 prevails in all histological groups in 89-100%.

CONCLUSION

We conclude that HPV does not seem, from the specific sample examined, to play a substantial role in oral carcinogenesis. However, it cannot be excluded that HPV could be involved in oral carcinogenesis only in cases with high viral load or at early stages of carcinogenesis possibly through the hit-and-run mechanism.

Laboratory surveillance of influenza virus in children under 10 years old, in northern Greece, during 2004-2010

OBJECTIVES

Influenza viruses constitute one of the most common pathogens that cause acute respiratory disease in children. The aim of this study is to present the contribution of influenza viruses to influenza-like illness (ILI) in children (aged<10 years old) in Northern Greece during six influenza seasons (2004-2010).

MATERIALS AND METHODS

1,242 pharyngeal swabs or/and washes from children younger than 10 years old, presented as ILI infections during the last six influenza seasons (2004-2005, 2005-2006, 2006-2007, 2007-2008, 2008-2009 and 2009-2010) were examined for influenza A and B by Real-time one step RT-PCR.

RESULTS

Influenza viruses were detected in 431 (34.7%) of the 1,242 specimens. In a total of 372 specimens were positive for influenza A and 58 for influenza B. The majority of the infected young patients were 6-10 years old (51.9%).

CONCLUSION

Our results show that in N. Greece, influenza viruses type A and B contribute to ILI presenting infections at a rate of 34.7 % in children younger than 10 years old.

Oseltamivir-resistant influenza A pandemic (H1N1) 2009 virus in Northern Greece

Resistance to oseltamivir was observed to influenza A pandemic (H1N1) 2009 virus strains, isolated from two patients in North Greece. Investigations showed resistant viruses with the neuraminidase (NA) 275Y genotypes. Pandemic A (H1N1) 2009 virus should be closely monitored for emergence of resistant variants.

Investigation of cytokine levels and their association with SCORAD index in adults with acute atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease with increasing frequency over the last decades, especially in adults. Cytokines orchestrate atopic skin inflammation. Objectives  The aim of this study was to compare serum levels of cytokines in adult patients with acute AD (AD1) with other groups of AD patients and controls and investigate the possible association between such cytokines and disease severity.

METHODS

We measured cytokine levels using flow cytometry in 21 adult patients with acute AD, 12 adults with chronic AD, 10 children with acute AD and 10 healthy adults.

RESULTS

Flow cytometry analysis of cytokines revealed that interleukin 10 (IL-10), IL-6, interferon γ (IFN-γ) and IL-4 levels were significantly decreased in AD1 group compared with controls, whereas IL-2 and tumour necrosis factor (TNF) did not differ. Comparison of AD1 group with adults chronic phase group showed that IgE, eosinophil and IL-2 levels remained unaltered, whereas IL-10, IL-6, IFN-γ, IL-4 and TNF were significantly decreased. SCORAD and IgE levels were significantly increased, IL-10, IL-6 and IFN-γ were decreased and TNF, IL-2, IL-4 and eosinophil levels remained unchanged in AD1 group compared with children acute phase group. Within AD1 group correlation analysis revealed that IgE and TNF levels were significantly associated with AD severity. Coefficient of determination analysis revealed that TNF and IgE levels could explain 49.14% and 35.28% of the variance of SCORAD.

CONCLUSIONS

These data indicate that serum IgE and TNF levels correlate with AD severity and that serum cytokines are downregulated in AD1 group. Further studies are clearly needed to elucidate cytokines' role in adults with AD.

Epidemiological and clinical characteristics of human parvovirus B19 infections during 2006-2009 in Northern Greece

Background. Parvovirus B19 infects children and adults, often causing erythema infectiosum, polyarthritis, but also aplastic crisis in patients with chronic haemolytic anaemia, rash, fever and fetal hydrops or fetal death. This study aims at the detection of acute parvovirus B19 infections during 2006-2009 in northern Greece on epidemiological and clinical aspect.Material and methods. Specimens were obtained from 63 patients, who addressed to hospitals, suspected for acute parvovirus B19 infection (17 in 2006, 29 in 2007, 10 in 2008 and 7 in 2009). Thirty (47.6%) were children (one day - 15 years old) and 33 (52.4%) were adults (16-65 years old). The infection was shown by PCR in whole blood and/or pleural fluid and supported by detection of specific IgM antibodies in the patients' blood serum, which was performed by ELISA.Results. Twenty (31.7%) out of the 63 specimens were found to be positive: 3/17 (17.6 %) in 2006, 16/29 (55.2 %) in 2007, none in 2008 and 1/7 (14.3%) in 2009, p=0.0002. Positive children were found 10/30 (33.3%) and positive adults 10/33 (30.3%). Specific IgM antibodies were detected in all 20 positive patients. Children developed hematological disorders, mainly types of anemia (6 cases), hydrothorax/ascites (2 cases), arthritis (1 case), and liver transplant rejection (1 case). Adults were presented with pregnancy complications (2 cases), arthralgia/arthritis (4 cases), febrile syndromes (3 cases) and atypical rash (1 case).Conclusions. In conclusion, an annual variation in the circulation of parvovirus B19 was noticed, presenting an increase of acute infections in northern Greece during 2007. Regarding serious cases, although children and adults seemed equally affected, differences in clinical manifestations were observed between them, with hematological dysfunctions predominant in childhood.

Epidemiological Study and Classification of ICU Infections, Using the Carrier State Criterion

This work aims at the better comprehension of epidemiology of ICU infections, using a classification based on the carrier state of the patient. This classification distinguishes the infections in primary endogenous (PE), secondary endogenous (SE) and exogenous (EX) infections. The material used was derived from ICU patients who were admitted to the ICU without being transferred from another ward of the same hospital or another hospital. Culture swabs were obtained from the pharynx and perineum of the patients at ICU admission and from then onwards every 3 days during their hospitalization. At the same time, cultures of clinical samples were carried out, on suspicion of infection. Ninety-six ICU patients were studied. In 31 of these, a total of 78 infections were developed. According to the proposed classification, 26 of the infections were PE (rate 33.3%), 34 SE (rate 43.6%) and 18 EX (rate 23.1%). Using the carrier state criterion, there were 11 fewer infections characterized as nosocomial (rate 14.1%), contrary to the 48-hour criterion. Based on this new taxonomy of infections, we are able to know in advance the source of the causative microorganisms and reduce the prevalence of ICU infections, by applying appropriate prevention and treatment strategies.

Contribution of human metapneumovirus to influenza-like infections in North Greece, 2005-2008

Following its detection in 2001, human metapneumovirus (hMPV) has repeatedly been reported as a respiratory pathogen, especially in children. This study was aimed at determining the proportion of hMPV infections in patients with influenza-like illness (ILI) during the three influenza seasons 2005-6, 2006-7, 2007-8 in northern Greece. We collected 380 nasopharyngeal swabs or aspirates from ILI patients during the winter seasons 2005-2008 and examined them for influenza viruses and hMPV by one-step real time RT-PCR and nested RT-PCR. Influenza viruses were detected in 151 of the 380 specimens (39.7%) and hMPV in 23 of them (6.05%). Co-infections with hMPV and influenza viruses were observed in seven cases. The majority of the ILI patients (60.5%) were 0-18 years-old. However, the incidence of influenza was slightly higher in the age group of 19-60-year-olds, while the incidence of hMPV infections was higher in the age group of 0-18-year-olds. We conclude that hMPV plays an important role as a contributor in influenza-like infections, especially in children. It circulates in the community during influenza seasons and its clinical appearance can be confused with influenza symptoms. However, further research is needed to elucidate the quantitative and qualitative importance of hMPV infections.

Hematopoietic cell transplantation and emerging viral infections

Viral infections remain important causes of morbidity and mortality in hematopoietic cell transplant recipients. More recent developments in preparative regimens and graft manipulations, as well as the control of well-recognized post-transplant infections by the introduction of prophylaxis and preemptive strategies, have influenced the timing and the epidemiology of infections. As new pathogens, such as human metapneumovirus (HMPV), human bocavirus, human coronaviruses HCoV-NL63 and HCoV-HKU1, human herpesviruses HHV-6 and HHV-7, and polyomaviruses, have emerged, it is fundamental to determine the significance of the newly discovered viruses and their role in the transplantation field. This article summarizes recent data on epidemiology and laboratory diagnosis of new pathogens, as well as clinical features and management of the associated infectious complications. J. Med. Virol. 82:528-538, 2010. (c) 2010 Wiley-Liss, Inc.

Seroepidemiology of Chlamydia Pneumoniae in Northern Greece

The prevalence of IgG and IgA antibodies to Chlamydia pneumoniae was evaluated in a group of an apparently healthy population in northern Greece. Serum samples were obtained over a period of one year (June 2006 to May 2007) from 530 individuals (300 males and 230 females, aged from 1 month to 90 years). The sera were tested for specific antibodies to C. pneumoniae by two commercial methods, an ELISA and a micro-IF assay based on the principles of MIF. The prevalence of IgG and IgA antibodies to C. pneumoniae was 53.2% and 45.9%, respectively, and was found to be unrelated to gender, even in the elderly >61 years old. The IgG antibody prevalence was low in children under 5 years old (7.7%), sharply increased by the age of 20 (40%) and continued to increase, gradually, to reach 80.1% in the elderly. IgA antibodies also increased with similar kinetics to IgG, although at a lower level (3.8–66.1%). Our results show that infection with C. pneumoniae is common in northern Greece. The high prevalence of IgA specific antibodies reported in the present study is due to primary infection at a young age, while in the elderly is probably due to infection or reinfection, although the option of persistence cannot be excluded.

Cluster of new influenza A(H1N1) cases in travellers returning from Scotland to Greece - community transmission within the European Union?

On 26 and 27 May, the Hellenic Centre for Disease Control and Prevention in Greece reported two confirmed cases of new influenza A(H1N1) virus infection in travellers returning from Scotland. The two cases had no apparent traceable links to an infectious source. Herein we report details of the two cases and potential public health implications.

Influenza A(H5N1): an overview of the current situation

Influenza viruses continue to threaten the world with a new pandemic. While currently attention is focused on the newly emerged A(H1N1) virus, the avian influenza A(H5N1) virus is still a cause of concern. Extended research is focused on the genetic evolution of the viruses, as well as their susceptibility to available antiviral drugs. One of the major priorities of the World Health Organization is to develop candidate vaccines, four of which are already licensed for use in the European Union. Since the last influenza pandemic in 1968, our knowledge of the influenza virus and its biology has greatly increased, revealing new avenues in the research for antiviral strategies and the development of effective vaccines.

Use of the AMPLIFIED Mycobacterium tuberculosis direct test for the diagnosis of tuberculosis

A comparative analysis was made of 3 conventional tests for tuberculosis (TB) versus a DNA probe technique among suspected TB patients at a reference centre in Greece. During 2004, we tested 2961 biological specimens from 2234 patients with the following methods: Ziehl-Neelsen staining, LöwensteinOJensen culture, BACTEC mycobacteria growth indicator tubes (MGIT) and the Gen-Probe AMPLIFIED Mycobacterium tuberculosis direct test (MTD). Of a total of 136 TB patients diagnosed and under anti-TB treatment, 133 of them (98%) were positive by amplified MTD. There were 112 TB (82%) detected by the MGIT method, 102 (75%) by Löwenstein-Jensen culture and 75 (55%) by Ziehl-Neelsen staining. Using MTD the positive result is ready within hours compared with days or weeks.

Rubella immunity and vaccination coverage of the population of northern Greece in 2006

This study was prompted by two rubella outbreaks that occurred in northern Greece in the last decade (1993 and 1999) and by periodic changes to the immunisation strategy. It was designed to determine the current status of rubella immunity and vaccination coverage in this region, eight years after the last outbreak in 1999 and seven years after the last epidemiological study in the area. Among the 685 subjects studied the seroprevalence was 83.7% and the total vaccination rate was 31.3%. In people born before the introduction in 1989 of the measles/mumps/rubella (MMR) vaccine into the national immunisation programme, higher rates of rubella seropositivity (88.1%) were observed compared to those born after 1989 (77.1%). The vaccination rates for these age groups were 14.8% and 58.1%, respectively. The reason for this difference is the lack of vaccination at the time these people were children, and it underlines the need for a vaccination strategy targeting older people as well. Among women of reproductive age (16-40 years), who represented 44.8% of the study population, 13.9% were susceptible to rubella and only 18.5% were vaccinated. These results indicate that there is a great need for a comprehensive policy designed to protect mostly young adults and women of childbearing age in order to prevent congenital rubella infections. This policy should also include competent surveillance systems for rubella and congenital rubella syndrome and an evaluation of existing immunisation programmes.

Greek measles epidemic strain, 2005-2006

The purpose of this work was the molecular study of the virus strain that caused the last measles outbreak in Greece. Twenty-four saliva specimens were obtained from selected patients serologically confirmed as measles cases between December 2005 and March 2006. Measles virus (MV) detection was performed by a nested RT-PCR. The 447-bp segment of the N gene of these MV strains was used for genotyping. The N gene sequences of the Greek MV strains were identical to each other, therefore a phylogenetic tree was constructed using one representative MV (ThesGRE/06). Our data show that the MV strain which caused the 2005-2006 outbreak in Greece belongs to genotype D6, and differs by 0.68% from the New Jersey D6 strain and by 5.5% from the MV vaccine strain Edmonston B (U03656) belonging to genotype A.

Association of protein-losing enteropathy and cryoglobulinaemia

We describe a case of protein-losing enteropathy in association with cryoglobulinaemia. No underlying disorder could be definitively diagnosed, but several clinical and laboratory findings suggested an immune mediated or autoimmune disorder. We propose that the mechanism of the protein-losing enteropathy in our case was immune complex formation, complement activation and endothelial damage.