Human cytomegalovirus: Infections and diagnosis

Human cytomegalovirus [HCMV] is a ubiquitous virus whose sole host is humans. Since HCMV can contagion from person to person through numerous ways, vast populations of humans are infected. HCMV infections can potentially have a range from asymptomatic infection in immuno-competent hosts to life-threatening diseases in organ recipients and patients with AIDS. The present article reviews the occurrence of HCMV infections and diseases in humans with different physiological and immunological status, and evaluates the existing laboratory methods for diagnosis of the disease

Kinetics of nitric oxide production and MTT reduction by HSV-1 infected macrophages

Macrophages have important role in defense against Herpes Simplex Virus type-1 [HSV-1]. The present study was performed to determine the viability and nitric oxide [NO] production by HSV-1 infected mouse peritoneal macrophages [HIM]. The viability of macrophages was evaluated using MTT reduction assay and the production of nitrite using Griess method. The ability of infected macrophages to reduce Tetrazolium [MTT] was diminished at virus to cell ratios of multiplicity of infection [MOI] of one, three and 10; but not at 0.01 and 0.1. Induction and inhibition of NO production by HIM were MOI dependent. The basal NO production by these cells was inhibited at MOI of three and ten. In contrast virus to cell ratios of 0.01 and 0.1 induced low but significant enhancement in NO production. The inability of HIM to reduce MTT at MOI of three was significant after 12-hrs and inhibition of NO production was initiated between 12-20 hours after infection. High doses of HSV-1 seem to decrease the normal activity of macrophages by inhibiting the production of nitric oxide

Determination of HCV genotypes, in Iran by PCR-RFLP

Hepatitis C is a major cause of liver related morbidity and mortality worldwide and represents a major public health problem. Depending on genomic organization, the virus is divided into six genotypes and a number of subtypes. Different genotypes are seen in different parts of the world. Genotype one is difficult to treat, while genotypes 2 and 3 are easy to treat. Therefore, identification of HCV genotype in patients is necessary to begin and follow up the treatment. In this study, viral genomic materials of 214 patients' sera were detected by nested-RT PCR. Based on genomic differences among different genotypes, the PCR products were digested with proper enzymes and studied by RFLP. Except for one, sequencing of 14 samples, representative of all genotypes, confirmed the results of PCR-RFLP. The results of PCR-RFLP were as follows: 1a [52.88%], 1b [14.01%], 3a [27.57%], 2a [2.1%], 4 [3.44%]. This indicates that a high percentage of HCV infected patients in Iran are infected with 1a or 3a genotypes. These findings reveal that the pattern of HCV genotypes in Iran differs from those of other middle-eastern countries

Pre-symptomatic human cytomegalovirus disease diagnosis in renal transplant recipients by the virus DNA PCR

Human cytomegalovirus [HCMV, CMV] is a major infectious complication of renal transplantation. The objective of this survey was to optimize and establish a polymerase chain reaction [PCR] technique for rapid and early detection of CMV disease in renal transplant recipients. In a cross sectional study, a total of eighty-one EDTA-blood samples were collected as simple nonrandomized [sequential] weekly from thirty-seven renal transplant recipients during a 1-6 months period after their transplantation in Kidney Transplant Center of Shaheed Labbafinejad Hospital of Tehran. Peripheral blood leukocytes [PBLs] were isolated and DNA was extracted. HCMV DNA in PBLs was detected by PCR using a conserved set of primers. Amplified fragment was confirmed by restriction fragment length polymorphism [RFLP] and sequencing. Correlation between PCR results and patients' data was analyzed. Twelve patients from thirty-seven renal transplant recipients had positive samples containing HCMV DNA in PBLs [32.4%], whereas, five of them showed symptomatic CMV disease [13.5%] and seven of them did not show symptomatic CMV disease, but had some signs of pre-symptomatic CMV disease. Twenty-five patients had negative PCR results, and all of them did not have symptomatic CMV disease. Considering type one error [alpha = 0.05], a nonparametric Fisher's exact test showed a good correlation between two variables of positive PCR results and symptomatic CMV disease in renal transplant recipients [P=0.002]. In conclusion, establishing methods for early detection of HCMV DNA, even prior to showing symptomatic CMV disease, has been shown to be an effective way for starting antiviral therapy, prior to patients' experience of symptomatic CMV disease