Human papillomavirus viral load: a possible marker for cervical disease in HIV-infected women

Laboratory markers of human papillomavirus infection have been recognized as relevant tools in programmes designed to reduce the burden of cervical cancer. The ongoing experience with these laboratory markers serves to confirm not only their negative predictive value (close to 100%) but also their positive association with developing or developed lesions. This aspect is particularly relevant in HIV-infected subjects who show an increased prevalence, incidence and severity of infections and lesions even in the era of efficacious control of their immunosuppression. Among the possible virus-related parameters proposed as relevant markers (viral persistence, load, expression, genomic integration capacity) we here analyse the informative value of human papillomavirus viral load measurement as a possible risk marker in this particular clinical setting.     

The emerging value of P-selectin as a disease marker.

Activated platelets are key components in many arterial disorders. P-selectin is an activation-dependent platelet receptor, which is also identified in endothelial cells. Together with E- and L-selectin it constitutes the selectin family. These transmembrane proteins have continued to attract great interest as they support rapid and reversible cell adhesion in flow systems and thus play an essential role in multicellular interactions during thrombosis and inflammation. Similarly to other lectins, selectins bind to different glycoconjugates with varying affinities. Protein ligands, equipped with the appropriate carbohydrate and sulfate moieties for P-selectin binding, have been identified in normal peripheral blood leukocytes and several non-hematopoietic organs, as well as on cancer cells. For diagnostic purposes, P-selectin can readily be detected on the platelet surface by flow cytometry and by ELISA as a soluble ligand in the plasma. Along with other markers, these data can be used in the assessment of platelet activation status. Such results bear clinical significance since P-selectin has been implicated in the pathogenesis of wide-spread disorders including coronary artery disease, stroke, diabetes and malignancy.     

Aspirin-induced asthma as a viral disease

A hypothesis is presented which states that aspirin-induced asthma results from chronic viral infection. This type of asthma has, indeed, a highly characteristic clinical course, reminiscent of viral upper respiratory tract infection. It is suggested that, in response to a virus, a long time after the initial exposure, specific cytotoxic lymphocytes are produced. Their activity is suppressed by prostaglandin E2 (PGE2) produced by pulmonary alveolar macrophages. Anti-cyclo-oxygenase analgesics block PGE2 production, and allow cytotoxic lymphocytes to attack and kill their target cells, i.e. the virus-affected cells of the respiratory tract. During this reaction, toxic oxygen intermediates, lysosomal enzymes and mediators are released, which precipitate attacks of asthma. These acute attacks can be prevented by avoidance of all drugs with anti-cyclo-oxygenase activity, however, asthma continues to run a protracted course because of chronic viral infection.     

CD3-negative lymphoproliferative disease of granular lymphocytes containing Epstein-Barr viral DNA.

Lymphoproliferative disease of granular lymphocytes (LDGL) is a heterogeneous disorder and the pathogenesis is likely to be complex. Some patients with chronic active EBV (CAEBV) infection also have LDGL. To investigate the relationship between EBV infection and the pathogenesis of LDGL, we conducted a survey for EBV DNA sequences by Southern blot analysis of DNA obtained from the peripheral blood of seven patients with LDGL, including one with CAEBV infection. Interestingly, EBV DNA was detected in the sample from the patient with CAEBV infection, and in the samples from four other patients with CD3-LDGL. Moreover, a single band for the joined termini of the EBV genome was demonstrated in two samples, suggesting a clonal disorder of those LDGL. These findings strongly suggest that EBV may play a pathogenic role in some cases of LDGL.     

Serum hyaluronan as a marker of liver fibrosis in asymptomatic chronic viral hepatitis B.

Increased concentrations of serum hyaluronan, a polysaccharide widely distributed in the extracellular space, have been demonstrated in liver disease of various aetiologies and proposed as a useful marker of liver fibrosis. The aim of the present study was to evaluate the association of serum hyaluronan with the extent of hepatic fibrosis in asymptomatic cases of chronic hepatitis B viral infection. The study was conducted in a consecutive sample of 111 asymptomatic chronic carriers of hepatitis B surface antigen. Liver function tests, alcohol consumption and cigarette smoking were determined and, for 84 subjects, liver biopsy was performed and degrees of inflammation and fibrosis were scored. Hyaluronan was measured using a radiometric assay. Mean serum hyaluronan increased with increasing fibrosis score (from 22.2 +/- 4.8 to 50.6 +/- 12.7 microg/l, p = 0.058) or pathological severity (from 18.8 +/- 5.9 to 50.6 +/- 12.5 microg/l, p = 0.048), even after adjusting for the effect of age. No such correlation was found with portal inflammation. The study showed that, in asymptomatic chronic carriers of hepatitis B, serum hyaluronan concentration correlates with hepatic fibrosis, a known marker of disease prognosis. This finding supports the hypothesis that hyaluronan might be of use in assessing and monitoring time trends in liver disease, substituting for repeated biopsies.     

Sonographic measurement of the inferior vena cava as a marker of blood loss

Detecting and monitoring blood loss in trauma patients can often be challenging when an obvious source of hemorrhage is not readily seen. OBJECTIVE: To provide a noninvasive measurement of circulating blood volume and of drop therein by measuring the change in the inferior vena cava diameter (IVCd) in relationship to blood loss. METHODS: This was a prospective observational study on blood donors at a donation center. The IVCd, both during inspiration (IVCi) and during expiration (IVCe), was measured in volunteers both before and after blood donation of 450 mL. All actual blood donors aged 18 years and older were eligible for enrollment. Persons who were younger than 18 years, who declined to participate in the study, or who did not meet blood center criteria for blood donation were excluded. All examinations were performed in the supine position with the ultrasound transducer placed in a subxyphoid location. Sagittal sections of the IVC behind the liver were imaged and the maximal diameter of the IVCe and the minimal diameter of the IVCi were measured. Statistical analysis included test for normality, paired t test, and correlation analysis. RESULTS: A total of 31 volunteers (18 male) with a mean age of 49.5 years (range, 18-73) were studied. The mean IVCe before blood donation was 17.4 mm (95% CI, 15.2-19.7 mm) and after blood donation was 11.9 mm (95% CI, 10.3-13.6 mm). The mean IVCi before blood donation was 13.3 mm (95% CI, 11.3-15.3 mm), but after blood donation was 8.13 mm (95% CI, 6.7-9.6 mm). The difference between IVCe before and after blood donation (dIVCe) was 5.5 mm (95% CI, 4.3-6.3 mm) yielding a P < .0001. The difference between IVCi before and after donation (dIVCi) was 5.16 mm (95% CI, 4.2-5.9 mm) yielding a P < .0001. The dIVCe and the dIVCi were closely correlated ( r = 0.83). Similarly, the pre-IVCe correlated well to the post-IVCe ( r = 0.74) and the pre-IVCi correlated well to the post-IVCi ( r = 0.75). CONCLUSIONS: Our data indicates that the measurement of the IVC diameter is a reliable indicator of blood loss, even in small amounts of 450 mL. On average, there was about a 5-mm decrease in both the IVCe and IVCi after donation of 450 mL of blood. The measurement of the IVCe may be an important addition to the ultrasonographic evaluation of trauma and other potentially volume-depleted patients.     

Effects of storage and viral load on hepatitis C viral genotyping.

Hepatitis C virus (HCV) genotyping is important for determining the treatment protocol for hepatitis C patients. Since amplified material from the Roche HCV Monitor kit is compatible with the Innogenetics INNO-LiPA HCV II kit (line probe assay), amplicons from the Monitor assay can be used to identify the HCV genotype. The Monitor package insert recommends using amplicons within a 7-day period (at 4 degrees C) following amplification. It was hypothesized that storage of amplicons for 4 weeks and longer (at -20 degrees C) would not affect the sensitivity of the genotyping assay. After denaturation, amplicons from two genotypes were stored for 7-386 days prior to performing the genotyping assay. Storage of amplicons did not hamper the ability to identify the genotype. Additionally, the sensitivity of the assay was evaluated by analyzing five genotypes with low viral loads. HCV genotypes were detected most consistently at viral levels of 10,000 copies/mL. In conclusion, the Innogenetics genotyping assay can use stored amplicons, thus reducing the cost of the assay by avoiding additional PCR reactions. Determining the sensitivity of this assay facilitates the efficient use of this test by incorporating a sensitivity cutoff of >or=10,000 copies/mL.     

Clinical utility of viral quantification as a tool for disease monitoring

The possibility to detect viral DNA or RNA in a quantitative manner has already contributed significantly to the management and diagnosis of viral infections, as well as to the understanding of virus-host interactions. New developments in amplification techniques based on real-time detection, as well as automation of the whole process, will soon be introduced in a diagnostic laboratory setting, thereby enabling a rapid turnaround time to generate both quantitative and qualitative results. New guidelines for disease management, as well as extensive quality control and standardization programs must be introduced.     

Pepsin as a marker for pulmonary aspiration.

BACKGROUND: Although assessment for aspiration of small volumes of gastric contents in tube-fed patients receiving mechanical ventilation is important, available methods for this purpose are not wholly satisfactory. A potential method is immunoassay of tracheal secretions for the gastric enzyme pepsin. OBJECTIVES: To determine the frequency with which pepsin in suctioned tracheal secretions from acutely ill, tube-fed patients receiving mechanical ventilation could be detected via an immunoassay. METHODS: A convenience sample of 136 specimens of suctioned tracheal secretions was collected from 30 acutely ill, tube-fed adults receiving mechanical ventilation. Multiple samples were obtained from 26 of the 30 patients (range, 2-11 per subject). An immunoassay with rooster polyclonal antibodies to purified human pepsin was used to detect pepsin in the secretions. RESULTS: Fourteen specimens tested positive for pepsin. Secretions from 5 patients accounted for the 14 pepsin-positive results. A significant relationship was found between the position of the head of the bed and the presence of pepsin in tracheal secretions (P<.001). Of the 14 pepsin-positive specimens, 13 (92.9%) were obtained from subjects in a flat position. CONCLUSIONS: A pepsin immunoassay can be used to detect pepsin in human tracheal secretions. If pepsin in tracheal secretions is considered an indicator of aspiration of gastric contents, aspiration occurred in 5 of the 30 subjects. A flat position is strongly associated with the presence of pepsin in tracheal secretions.     

Quantification of cytomegalovirus viral load

Cytomegalovirus (CMV), a member of the Herpesviridae family, is worldwide distributed. After the primary infection, CMV induces a latent infection with possible reactivation(s). It is responsible for severe to life-threatening diseases in immunocompromised patients and in foetuses and newborns of infected mothers. For monitoring CMV load, classical techniques based on rapid culture or pp65 antigenemia are progressively replaced by quantitative nuclear acid tests (QNAT), easier to implement and standardize. A large variety of QNAT are available from laboratory-developed assays to fully-automated commercial tests. The indications of CMV quantification include CMV infection during pregnancy and in newborns, and viral surveillance of grafted and non-grafted immunocompromised patients, patients with bowel inflammatory diseases and those hospitalised in intensive care unit. A close cooperation between virologists and clinicians is essential for optimizing the benefit of CMV DNA monitoring.     

Soluble P-selectin as a marker of platelet hyperactivity in patients with chronic obstructive pulmonary disease.

A comparative analysis between soluble (s) P-selectin and von Willebrand Factor (vWF) was performed in 40 patients with chronic obstructive pulmonary disease (COPD) and 20 healthy subjects, with the aim of investigating whether the occurrence of elevated levels of sP-selectin may reflect activation of platelets, endothelial cells, or both. Plasma sP-selectin levels were significantly higher in patients compared to controls (P < 0.01). Similarly vWF levels were elevated in patients compared to healthy subjects, although the difference did not reach statistical significance. Lipoprotein (a) [Lp(a)] levels were lower in COPD patients than controls (P < 0.0001). The analysis of the correlation among all the variables demonstrated that plasma sP-selectin did not correlate with vWE. Conversely, plasma sP-selectin levels significantly correlated with either oxygen (rho = -0.41, P < 0.05) or carbon dioxide (rho = 0.47, P < 0.05) tension. An inverse correlation between serum Lp(a) and plasma sP-selectin levels (rho = -0.35, P < 0.05) was also observed. Moreover, increasing levels of sP-selectin in COPD patients significantly correlated with the impairment of blood gas tensions. In conclusion, the results obtained indicate the prominent platelet origin of circulating sP-selectin, suggesting that sP-selectin might be considered a marker of in vivo platelet activation in patients with COPD.