Sahar Essa

Th1-type cytokines production is decreased in kidney transplant recipients with active cytomegalovirus infection

Cytomegalovirus (CMV) infection is a major complication after kidney transplantation. Despite antiviral therapy the infection contributes significantly to high morbidity. The present study was aimed at determining: (a) the stimulation index (S.I.) of phytohemagglutinin (PHA)‐stimulated peripheral blood mononuclear cells (PBMC) and (b) the levels of Th1‐ and Th2‐ related cytokines in kidney transplant recipients with and without active CMV infection. Thirty‐five patients with, and 44 without active CMV infections, as diagnosed by a CMV antigenemia assay, were inducted into this study. After PHA stimulation of PBMC from patients, stimulation index (S.I.) was determined by radioactive thymidine uptake while the production of Th1‐type cytokines (interleukin‐2 [IL‐2], interferon‐γ [IFN‐γ], and tumor necrosis factor‐α [TNF‐α]) and Th2‐type cytokines (IL‐4, IL‐10) were measured by enzyme‐linked immunosorbent assay. PBMC of patients with active CMV infection showed significantly lower S.I. values than patients without an ongoing CMV infection (P < .0001). Levels of Th2‐type cytokines in CMV‐infected and uninfected kidney recipients were similar; however, the levels of the Th1‐type cytokines were significantly lower in CMV‐infected patients. Low levels of Th1‐type cytokines seem to correlate well with active CMV infection in kidney recipients. J. Med. Virol. 60:223–229, 2000.

Correlation between CMV genotypes, multiple infections with herpesviruses (HHV-6, 7) and development of CMV disease in kidney recipients in Kuwait

The possible correlation between cytomegalovirus, human herpesvirus types 6, 7 and cytomegalovirus-related clinical symptoms was studied in kidney transplant patients in Kuwait. Cytomegalovirus infection was diagnosed using the pp65 antigenemia assay. DNA of cytomegalovirus was detected by nested polymerase chain reaction (nested-PCR). PCR was also used to amplify the genes coding for structural proteins of human herpesvirus-6 (240 bp) and human herpesvirus-7 (186 bp). Glycoprotein B genotypes of cytomegalovirus were determined by restriction fragment length polymorphism. The average number of cells positive for cytomegalovirus pp65 antigen showed a steady increase with the severity of the cytomegalovirus-related symptoms. Furthermore, cytomegalovirus pp65 antigen positivity was significantly more frequent among recipients of cadaver kidney (45.5%) than among those who received live related kidneys (22.6%). Cytomegalovirus gB genotype 1 was detected more frequently (P<0.036) in recipients with live related donor kidney (38%) than in patients of cadaver kidney (13%). The genome of human herpesvirus-6 was detected at the same rate in patients with or without cytomegalovirus-related symptoms. However, the genome of human herpesvirus-7 was detected significantly more frequently (P<0.0001) in asymptomatic patients (41.7%) than in recipients with symptomatic cytomegalovirus infection (17%). We conclude that cytomegalovirus gB genotypes are not associated with the outcome of a cytomegalovirus infection in kidney transplant patients, that human herpesvirus-6 does not play a role in cytomegalovirus pathogenesis and that the role of human herpesvirus-7 in cytomegalovirus-related morbidity in kidney recipients remains unclear.

The use of flow cytometry for the detection of CMV-specific antigen (pp65) in leukocytes of kidney recipients

Flow cytometric assay (FCA) was used to detect a cytomegalovirus (CMV) specific antigen (pp65) in CMV‐infected fibroblast cells and in leukocytes of kidney recipients. FCA distinguished clearly between the infected and non‐infected fibroblast cells. Regarding transplant patients, the FCA was positive when the number of antigenemia assay (AA) positive cells was five or more per 5×104. Moreover, the percentage of antigenemia‐positive cells by FCA correlated well with symptomatic CMV infections.

Mixed Viral Infections Circulating in Hospitalized Patients with Respiratory Tract Infections in Kuwait

The aim of this study was to determine the frequency of viral mixed detection in hospitalized patients with respiratory tract infections and to evaluate the correlation between viral mixed detection and clinical severity. Hospitalized patients with respiratory tract infections (RTI) were investigated for 15 respiratory viruses by using sensitive molecular techniques. In total, 850 hospitalized patients aged between 3 days and 80 years were screened from September 2010 to April 2014. Among the 351 (47.8%) patients diagnosed with viral infections, viral mixed detection was identified in 49 patients (14%), with human rhinovirus (HRV) being the most common virus associated with viral mixed detection (7.1%), followed by adenovirus (AdV) (4%) and human coronavirus-OC43 (HCoV-OC43) (3.7%). The highest combination of viral mixed detection was identified with HRV and AdV (2%), followed by HRV and HCoV-OC43 (1.4%). Pneumonia and bronchiolitis were the most frequent reason for hospitalization with viral mixed detection (9.1%). There were statistical significance differences between mixed and single detection in patients diagnosed with bronchiolitis (P = 0.002) and pneumonia (P = 0.019). Our findings might indicate a significant association between respiratory virus mixed detection and the possibility of developing more severe LRTI such as bronchiolitis and pneumonia when compared with single detection.

Low Levels of Th1-Type Cytokines and Increased Levels of Th2-Type Cytokines in Kidney Transplant Recipients With Active Cytomegalovirus Infection

BACKGROUND Cytomegalovirus (CMV) infection is a major complication after kidney transplantation. It is clear that Th1 and Th2 cell subsets are of major importance in determining the class of immunoprotective function in infectious diseases. Given the strong influence exerted by Th1- and Th2-type immunity on the outcome of infections, we felt it important to elucidate the levels of Th1- and Th2-type cytokines to CMV-related antigens in kidney recipients and to identify antigens that play an essential role in preventing the development of CMV infection and/or disease. METHODS One hundred twenty subjects were followed for CMV infection by the antigenemia assay. We investigated peripheral blood mononuclear cells (PBMCs) responses to five CMV-related peptide antigens (pp65, gB, pp150, pp28, and pp38). Stimulation index was determined by radioactive thymidine uptake, while the production of Th1-type cytokines (interferon-gamma and tumor necrosis factor-alpha) and Th2-type cytokines (interleukins-4 and -10) were measured by enzyme-linked immunosorbent assay. RESULTS The levels of Th1-type cytokine production after stimulating PBMCs with CMV-related antigens gB and pp150 resulted in significant decreases in the levels of interferon-gamma, while pp65, pp150, and pp38 produced significant decreases in the level of tumor necrosis factor-alpha between the two groups (P < .05). For Th2-type cytokines only pp28 produced a significant increase in the level of interleukin-10 between the two groups (P < .05). Regarding the Th1:Th2 ratios, a lower Th1-bias was observed among the CMV-positive patients for PBMCs stimulated with three CMV-related antigens (pp65, pp38, and pp28). CONCLUSION Low levels of Th1-type cytokines and increased levels of Th2-type cytokines upon stimulation with CMV-related peptide antigens were associated with reduced cell-mediated immunity to CMV, thus seeming to correlate with active CMV infections.

The Prevalence of Human Bocavirus, Human Coronavirus-NL63, Human Metapneumovirus, Human Polyomavirus KI and WU in Respiratory Tract Infections in Kuwait

Objective: The aim of this study was to investigate the prevalence of human coronavirus (HCoV)-NL63, human metapneumovirus (hMPV), human bocavirus (Boca), human polyomavirus KI (KIV) and human polyomavirus WU (WUV) in respiratory tract infections (RTI) in Kuwait. Materials and Methods: Respiratory samples from 735 hospitalized patients with RTI from September 2010 to April 2013 were evaluated for the presence of HCoV-NL63, hMPV, Boca, KIV and WUV using molecular assays, polymerase chain reaction (PCR) and reverse-transcription PCR. Results: Of the 735 patients, 285 (38.8%) were diagnosed with viral RTI. The distribution of respiratory viruses was hMPV: 15 (5.3%), Boca: 14 (4.9%), WUV: 10 (3.5%) and KIV: 4 (1.4%). HCoV-NL63 was not detected in any of the samples. Conclusions: These newly discovered viruses were associated with the development of RTI in Kuwait. The rapid identification of these viral infections could aid in the control of nosocomial transmission, reduce the use of antibiotics and improve treatment and management strategies.

Diagnosis of Cytomegalovirus Infection by the Detection of Early Antigen (pp65) in Leukocytes of Kidney Transplant Patients

Objective: Cytomegalovirus (CMV) infection is a frequent complication of kidney transplantation contributing substantially to morbidity and mortality. Early diagnosis of the infection is essential to implement an effective antiviral therapy. This study is aimed at establishing the CMV antigenemia assay for the diagnosis of CMV infection, and for monitoring the effectiveness of ganciclovir therapy in kidney recipients in Kuwait. Methods: Leukocyte-enriched fractions of 215 blood specimens from 92 kidney recipients were processed for the detection of CMV-specific protein (pp65) by using a commercial kit (Incstar Corp., USA). Plasma fractions were also tested for the presence of CMV IgM antibodies, and selected samples (n = 15) were processed for virus isolation in MRC-5 diploid cell culture. Results: Regarding symptomatic (n = 35) and asymptomatic patients (n = 57) the assay showed an 86% positive and a 79% negative predictive value, compared to the 55% and 70% values, respectively, for CMV IgM antibodies. The number of positive cells was parallel with the severity of symptoms. Using a cutoff level of >5 antigen-positive leukocytes/50,000 cells, the assay reached 93% positive and 96% negative predictive values. There was a very good agreement between the assay and virus isolation. Ganciclovir therapy could be monitored effectively with the assay, and in 11 symptomatic patients treated with ganciclovir, a prompt decrease in the number of antigen-positive cells was noted. Conclusion: The CMV antigenemia assay is a valuable tool for the early diagnosis of symptomatic CMV infection and monitoring antiviral therapy in kidney transplant patients.

Seroprevalence of human parvovirus B19 in children of a desert region

A seroepidemiological study was conducted in Kuwait to evaluate the pattern of acquisition of human parvovirus B19 by children in Kuwait and to compare it with patterns described in other regions in different climatic zones. A total of 218 serum samples from children less than 16 years of age were tested for the presence of anti-B19 IgG by enzyme immunoassay. The overall seroprevalence was 17.4%. Infants in Kuwait had low levels of maternally-acquired anti-B19 IgG (8.6%). The age of peak exposure to parvovirus B19 was 10-15 years compared with less than 10 years in England and Wales and more than 20 years in Singapore. The results of this study indicate an influence of geographic differences on transmission of parvovirus B19.

Adherence ofStaphylococcus epidermidis to pharyngeal epithelial cells mediated by lipoteichoic acid

Prior treatment of pharyngeal epithelial cells (PEC) with lipoteichoic acid (LTA) derived fromStaphylococcus epidermidis produced a marked inhibition of adherence of the homologous strain and two heterologous strains. The inhibition was dose dependent and saturable with 100 µg/ml of LTA. However, pretreatment of PEC with deacylated LTA did not block the adherence of the three strains tested. A similar but less marked blocking effect on the adherence ofS. epidermidis to PEC was also observed with LTAs derived fromS. aureus andStreptococcus pyogenes. On treatment of bacteria with substances capable of binding to LTA, such as polyclonal mouse anti-LTA antibodies or with human albumin, a marked inhibition of bacterial adherence was observed. Immunofluorescence studies showed that anti-LTA antiserum bound readily to the surface of bacterial cells. These findings provide clear evidence that the lipid component of LTA located on the bacterial surface is centrally involved in the adherence ofS. epidermidis to human mucosal cells.

The potential influence of human parainfluenza viruses detected during hospitalization among critically ill patients in Kuwait, 2013–2015

BackgroundThe four types of human parainfluenza viruses (PIV) are important causes of community-acquired pneumonia, particularly in children; however, limited information exists about the incidence of PIV in critically ill patients. The aim of this study is to describe the spectrum, incidence and clinical features of PIV-associated infections diagnosed during the hospital stay of patients admitted to pediatric intensive care unit (PICU) and intensive care unit (ICU) of 5 medical centers across Kuwait.MethodsThis was a population-based, retrospective study from 2013 to 2015. Specimens were analyzed by molecular methods. This analysis was performed using the database of Virology Unit, Mubarak Al-Kabeer Hospital. Data from 1510 admitted patients with suspected respiratory viral infections was extracted.ResultsThe database contained a total of 39 (2.6%) patients infected with PIV (53.8% male and 46.2% females) and 20 (51.3%) were under 1 year of age. The most frequently isolated type was type 3 (28, 71.8%) followed by type 1 (9, 23.1%). At admission the most common clinical diagnosis was pneumonia in 12 patients (30.8%, p < 0.05) followed by bronchiolitis in 10 patients (25.6%).ConclusionPIV plays an important yet unrecognized role in the outcomes of PIUC and ICU patients. Our results contribute to the limited epidemiologic data of PIV in PIUC and ICU in this region.