[In vitro susceptibility to ganciclovir and foscarnet of cytomegaloviruses]

Ganciclovir is the drug of choice for the treatment of acute cytomegalovirus infections. This antiviral agent is a nucleoside analog of guanine whose activity is dependent upon its intracellular phosphorylation to the triphosphate derivative. Foscarnet is used to treat immunosuppressed patients such as organ transplant recipients and AIDS patients with cytomegalovirus who do not tolerate or develop resistance to ganciclovir. Foscarnet is a pyrophosphate analog that directly inhibits viral DNA polymerase. Resistant isolates have been recovered from immunocompromised patients treated with both anticytomegalovirus compounds. The aims of this study were to prepare a plaque reduction assay to study the in vitro susceptibility of cytomegalovirus to ganciclovir and foscarnet, and to apply it to the knowledge of in vitro susceptibility values of cytomegalovirus isolated from clinical samples. Eighty isolates from patients who had never been treated with ganciclovir or foscarnet were tested for antiviral susceptibility. The plaque reduction assay took 6-8 weeks. The results are expressed as ID(50) (inhibitory dose 50), and the ID(50) values of ganciclovir were between 2.14 and 13.49 microM. The ID(50) for ganciclovir was higher that 12 microM in only two cases (2%). The molecular study of the DNA of these did not show any mutation in the UL97 gene. The ID(50) values of foscarnet were between 46.65 and 460.22 microM. In 78 cases (98%) foscarnet ID(50) was lower than 400 microM. These results were comparable with those obtained by other authors. To summarize, the frequency of cytomegalovirus strains resistant in vitro to ganciclovir and foscarnet in previously untreated patients was low and when it was present it did not involve therapeutic failure since the patients progressed favorably.

Thrombocytopenia associated with liver cirrhosis and hepatitis C viral infection: role of thrombopoietin

BACKGROUND/AIMS

Thrombocytopenia in chronic liver diseases has traditionally been considered a consequence of platelet pooling and destruction in spleen. We tried to evaluate the influence of thrombopoietin, the physiological regulator of thrombopoiesis, on the origin of this thrombocytopenia.

METHODOLOGY

We determined serum thrombopoietin levels by ELISA in thrombocytopenic patients with liver cirrhosis (n = 32) and with chronic hepatitis C viral infection (n = 23). A group of 43 healthy subjects was used as a control.

RESULTS

Liver cirrhosis patients presented slightly, but not significantly, lower serum thrombopoietin levels (104 +/- 56 pg/mL) than controls (121 +/- 58 pg/mL) or patients infected with chronic hepatitis C virus (125 +/- 40 pg/mL). No correlations were found between serum thrombopoietin concentrations and liver tests or hematological parameters.

CONCLUSIONS

We conclude that low thrombopoietin production may play a role, along with hypersplenism, in the development of thrombocytopenia in patients with liver cirrhosis. Normal thrombopoietin levels exclude a defect in thrombopoietin production as a possible etiology for the thrombocytopenia in patients with chronic hepatitis C viral infection. However, a direct viral megakaryocyte infection or an immune mechanism could explain this thrombocytopenia, according to the thrombopoietin levels detected.

Serum thrombopoietin levels in thrombocytopenic and non-thrombocytopenic patients with human immunodeficiency virus (HIV-1) infection

HIV-1 seropositive patients often exhibit thrombocytopenia, considered of multifactorial aetiology. Thrombopoietin (TPO), a recently isolated cytokine, is the main regulator of megakaryocyte and platelet production. The objective of this study was to analyse serum TPO levels in thrombocytopenic and non-thrombocytopenic HIV-1 infected patients. Serum TPO levels were measured by ELISA in 43 healthy individuals and in 88 HIV-1 infected patients: 68 thrombocytopenics and 20 non-thrombocytopenics. Thrombocytopenic HIV-1 infected patients showed higher TPO concentrations (263 +/- 342 pg/ml) than non-thrombocytopenics (191 +/- 86 pg/ml); levels in both groups were significantly higher than those of healthy controls (121 +/- 58 pg/ml). Two subgroups of thrombocytopenic patients, the autoimmune thrombocytopenic purpura (AITP) group and the mild thrombocytopenic group, presented TPO levels similar to those of non-thrombocytopenics. Patients exhibiting pancytopenia showed the highest TPO concentrations. However, there was no correlation between TPO levels and platelet counts in any group of HIV-1 infected patients. TPO levels in HIV-1 seropositive patients were slightly increased and the differences in TPO levels between thrombocytopenic and non-thrombocytopenic patients were generally small. The finding of mildly increased TPO levels along with the recently described recovery of thrombocytopenia following recombinant TPO administration confirms the implication of ineffective platelet production in the origin of HIV-associated thrombocytopenia.

Community respiratory virus infections in patients with hematologic malignancies

BACKGROUND AND OBJECTIVE

The main difficulty of PCR-based clonality studies for B-cell lymphoproliferative disorders (B-LPD) is discrimination between monoclonal and polyclonal PCR products, especially when there is a high background of polyclonal B cells in the tumor sample. Actually, PCR-based methods for clonality assessment require additional analysis of the PCR products in order to discern between monoclonal and polyclonal samples. Heteroduplex analysis represents an attractive approach since it is easy to perform and avoids the use of radioactive substrates or expensive equipment.

DESIGN AND METHODS

We studied the sensitivity and specificity of heteroduplex PCR analysis for monoclonal detection in samples from 90 B-cell non Hodgkin's lymphoma (B-NHL) patients and in 28 individuals without neoplastic B-cell disorders (negative controls). Furthermore, in 42 B-NHL and in the same 28 negative controls, we compared heteroduplex analysis vs the classical PCR technique. We also compared ethidium bromide (EtBr) vs. silver nitrate (AgNO(3)) staining as well as agarose vs. polyacrylamide gel electrophoresis (PAGE).

RESULTS

Using two pair consensus primers sited at VH (FR3 and FR2) and at JH, 91% of B-NHL samples displayed monoclonal products after heteroduplex PCR analysis using PAGE and AgNO(3) staining. Moreover, no polyclonal sample showed a monoclonal PCR product. By contrast, false positive results were obtained when using agarose (5/28) and PAGE without heteroduplex analysis: 2/28 and 8/28 with EtBr and AgNO(3) staining, respectively. In addition, false negative results only appeared with EtBr staining: 13/42 in agarose, 4/42 in PAGE without heteroduplex analysis and 7/42 in PAGE after heteroduplex analysis.

INTERPRETATION AND CONCLUSIONS

We conclude that AgNO(3) stained PAGE after heteroduplex analysis is the most suitable strategy for detecting monoclonal rearrangements in B-NHL samples because it does not produce false-positive results and the risk of false-negative results is very low.

Conventional respiratory viruses recovered from immunocompromised patients: clinical considerations

Lower respiratory tract infection is the most common complication in the immunocompromised patient. From January 1991 to December 1995, 785 consecutive patients with suspected respiratory tract infections were studied. One hundred ninety-nine viruses were isolated from 182 (23%) of 785 bronchoalveolar lavage fluid specimens. Cytomegalovirus was isolated from 131 patients, herpes simplex virus was recovered from 31, and conventional respiratory viruses (CRVs) were recovered from 36. There were 9 influenza A viruses, 2 influenza B viruses, 7 parainfluenza viruses, 5 respiratory syncytial viruses, 5 adenoviruses, 6 enteroviruses, and 3 rhinoviruses. We identified 22 patients from whom a CRV was the only microorganism recovered; 13 patients developed pneumonia, 10 had acute respiratory failure, 5 required support with mechanical ventilation, and 5 (23%) died. In conclusion, CRVs are frequent causes of respiratory illnesses and are associated with high rates of morbidity and mortality among immunocompromised patients.

Pulmonary enterovirus infections in stem cell transplant recipients

In recent years, it has been recognised that the community respiratory viruses are a frequent cause of upper and lower respiratory tract infections in immunocompromised hosts such as bone marrow transplant recipients. By contrast, infections by non-polio enteroviruses have rarely been reported after stem cell transplantation. We present four cases of acute respiratory illness with enterovirus isolated as the sole pathogen from bronchoalveolar lavage. All four patients developed pneumonia and three died of progressive pneumonia, which reflects the severity of this complication. We conclude that enteroviral pulmonary infections may be a cause of severe pneumonia in immunocompromised hosts.

[Mucocutaneous manifestations in acute HIV infection. 3 case reports]

We report three patients who developed a generalized rash with oral, genital or perianal ulcerations as a result of acute infection due to HIV. The primary infection was diagnosed by seroconversion (by means of EIA and Western blot techniques). Definitive diagnosis was established on days 52, 85 and 97 after the appearance of the rash. The p24 protein of the HIV was only detected in the early phase of the disorder in the two cases in which this study was carried out.

Cytomegalovirus pp65 antigenemia-guided pre-emptive treatment with ganciclovir after allogeneic stem transplantation: a single-center experience

The optimal prophylactic strategy for cytomegalovirus (CMV) disease after allogeneic hematopoietic stem cell transplantation has not yet been established. The aim of this study was to analyze our single-center experience with a uniform protocol of CMV antigenemia-guided pre-emptive treatment with ganciclovir (GCV) after allografting. Fifty-two consecutive adult patients, 48 of them transplanted from HLA-identical matched related donors were included. T cell-depleted marrow or peripheral blood were used in 21 cases. After engraftment, weekly blood samples were tested for CMV pp65 antigenemia and viremia (conventional cultures) until day +100. GCV was started if CMV antigenemia and/or CMV viremia were detected. CMV infection (CMV-I) was found in 19 patients (37%). Seven patients suffered from CMV disease (CMV-D), three colitis and four pneumonias. There was one death directly related to CMV-D and three further cases died from refractory GVHD with CMV-D. Only one patient developed CMV pneumonia without any previous positive antigenemia and/or viremia. Multivariate analysis identified grades II-IV acute GVHD (P = 0.02) and peripheral blood stem cell transplantation (P = 0.03) to be risk factors for developing CMV-I. In conclusion, this monitoring protocol allowed early treatment of CMV-I without progression to CMV-D. Pre-emptive therapy had the additional advantage of avoiding GCV administration in most of our allograft recipients.

[Prevalence of human immunodeficiency virus infection and behaviors associated with its transmission among parenteral drug users selected on the street]

BACKGROUND

To estimate the prevalence of HIV infection and the associated risk behaviours among intravenous drug users not receiving treatment for their drug dependence.

PATIENTS AND METHODS

A cross-sectional study of 200 intravenous drug users recruited from the streets of Barcelona in 1993. Information about the socio-demographic aspects and behaviours was obtained through a personal interview using a standardised questionnaire which was carried out by three ex-drug users. Saliva samples were used to determine anti HIV antibodies.

RESULTS

The prevalence of HIV infection was 51%. 57% borrowed used syringes, 65% lended their syringes, and 41% practised back of frontloading. 85% if those who shared syringes always cleaned them, however 59% only used water. 78% had heterosexual relations, in 33% of the cases with a non-injecting sexual partner. 65% always used condoms with sexual clients although only 26% always used them with stable sexual partners and 36% with casual sexual partners. 78% had performed the HIV test and among those who knew they were seropositive, 40% had received some kind of health control in the last 6 months. Not having a legal income, injecting speedball or barbiturates, unknowing self HIV negative status and practicing forms of indirect sharing were found to be independently associated with syringe sharing.

CONCLUSIONS

The high prevalence of HIV infection and associated risk behaviours highlights the need to increase and adapt the prevention efforts and investigation to this group. Social marginalization and poliuse of drugs should be addressed in HIV prevention programs.

[Abdominal pain as the initial symptom of visceral varicella zoster infection in hematopoietic stem cell transplant recipients]

Varicella zoster virus (VZV) infections are an important cause of morbidity after stem cell transplantation (SCT), with no differences in their overall incidence between allogeneic and autologous transplants. We report four patients who developed a disseminated VZV infection with visceral involvement after an allogeneic (n = 3) or autologous (n = 1) SCT. In all 4 cases, the initial symptom was severe abdominal pain which preceded the appearance of the classical herpetic vesicular skin lesions from two to four days in three cases, while one never developed skin lesions. The interval from the transplant to the infection ranged from 5 to 13 months, and all three allogeneic SCT received a T-cell depleted graft, although two suffered from chronic GVHD. All patients had clinical, radiologic and/or biochemical findings indicative of gastrointestinal or visceral involvement. An extensive bibliography review of this specific form of presentation of disseminated VZV infection is presented. The interval from the abdominal pain to the development of the skin lesions has ranged from one to 10 days, and this has led to a delay in the initiation of specific antiviral therapy in many cases, including our only fatal case. We conclude that an abdominal pain of unknown origin in this particular clinical setting should always be regarded as a possible prodromal phase of a disseminated VZV infection.

Histopathological changes of primary HIV infection. Description of three cases and review of the literature

The histopathological changes observed in the cutaneous rash of three patients who suffered the acute phase of HIV infection are described. In all three patients a perivascular and interstitial inflammatory infiltrate was present in the upper and mid-reticular dermis. In one biopsy isolated areas of epidermal necrosis were observed and in the two other biopsies a perifollicular inflammatory infiltrate was detected with perforation in one case. Furthermore, a periductal infiltrate was observed in one of these biopsies.

[Etiology of enteritis in a university general hospital in Barcelona (1992-1995)]

BACKGROUND

The aim of the study was to describe the etiology of enteropathogenic agents over a four-year period (1992-1995) in a University Hospital in Barcelona.

METHODS

We studied 12,793 stool samples, 4519 were obtained from patients under 15 years and 8274 were obtained from patients over 14 years. The specimens were examined for bacteriological, parasitological and virological enteropathogens.

RESULTS

In 3380 specimens of 12,793 stool samples studied were identified an enteropathogen (26.4%). Polymicrobial associations were observed in the 6.8% of the cases. Pathogens were identified in 45% of children samples and 16.3% of adults samples. The etiological enteritis agents more frequently detected in the paediatric patients were Campylobacter (13.5%), rotavirus (11.3%) and Salmonella (10.2%); and Salmonella (4.9%), Campylobacter (3.1%) and Giardia intestinalis (2.1%) in adults. Cryptosporidium (13.5%) was the most frequent cause of gastrointestinal tract infections in HIV-infected subjects. In the children with stools positives, the presence of red and white blood cells were more frequent than the adults with stools positives (73% versus 26.6%).

CONCLUSIONS

The enteropathogenic agents such as Campylobacter, Salmonella, and Giardia were the most frequent cause of gastroenteritis in our environment. In the children, rotavirus infections predominated during the cold months. The most frequent cause of gastroenteritis in HIV-infected patients was Cryptosporidium followed by Campylobacter.

Epstein-Barr virus infection associated with interstitial nephritis and chronic fatigue

Severe renal disease in the setting of Epstein-Barr virus (EBV) infection is exceedingly rare. We report here the case of a 22-year-old man with acute EBV infection associated with severe interstitial nephritis. The patient developed chronic fatigue and chronic renal failure with a serological profile typical of primary EBV infection. Clinical improvement with anti-EBNA seroconversion occurred after acyclovir therapy. Our patient illustrates that chronic fatigue with major organ dysfunction and a serological profile of primary infection can be seen in chronic EBV infection. In such a case, acyclovir may prove beneficial.

Testing of saliva and serum for HIV in high-risk populations. Ad Hoc Group for the Comparative Saliva and Serum Study

Paired samples of saliva and serum from 286 high-risk subjects were tested for HIV using two commercial enzyme immunoassays following the same WHO testing strategy supplemented with a Western blot technique. Agreement between HIV testing in both sample types was 98.9% (95% confidence interval: 97.7-100). The sensitivity of an EIA (Wellcozyme GACELISA) alone for saliva was 100% (133/133) and the specificity 98.7% (151/153). These results support previous data showing that in some situations saliva might be an effective alternative to serum for HIV testing.

Disseminated cytomegalovirus infection in an immunocompetent adult successfully treated with ganciclovir

We report the case of a previously healthy man who suffered a disseminated cytomegalovirus infection. He presented with prolonged fever, weight loss of 8 kg, anicteric hepatitis, upper digestive tract bleeding from gastric ulcers, acute polyneuritis and bilateral retinitis. Immunodeficiency was not detected either during admission or during a 3-year follow-up period. The patient was treated with ganciclovir (5 mg/kg BID) during 4 weeks with a favourable clinical outcome. To our knowledge, this is the first reported case with such characteristics.

[Isolation, sequencing and ultrastructure of HTLV-I and HTLV-II retroviruses. Presence of the HTLV-II subtype b among Spanish intravenous drug addicts]

BACKGROUND

Six cases of HTLV-I/II infection were selected for isolation and characterization of these retrovirus.

METHODS

Detection of anti-HTLV antibodies was carried out by enzyme immunoassay (EIA), immunofluorescence (IFI), and Western blot (WB). Analysis of proviral DNA was performed by PCR. Viral culture and partial sequencing of the pol and pX genes were carried out. Electron microscopy morphologically characterized the viral particles.

RESULTS

Serologic study demonstrated four cases of HTLV-II, one of HTLV-I, and one non-typeable HTLV infections. This last case was confirmed as positive for HTLV-II by PCR. Five new HTLV-II and one HTLV-I infected cell lines have been established by co-culture. Electron microscopy allowed morphologic characterization of the viral particles found in the infected cells. The sequence of the five strains of HTLV-II was identical demonstrating a divergence of 0.49% in the pX region and of 4.5% in the pol region compared with the HTLV-II Mo prototype. Comparison of these sequences with those corresponding to different strains of HTLV-II isolates from American Indians (subtypes b) suggest that these Spanish strains are more closely related with the subtype b than with the subtype a (HTLV-II Mo). Genetic variability study did not reveal any change in the sequence of these stains suggesting that the variability of these retroviruses in very infrequent in the regions studied. The analysis of the pol region of the HTLV-I strain demonstrated a divergence of 3.4% with respect to the sequence of the ATK-1 prototype (Japan) and of 1.7% of the strain HS-35 (Caribbean) showing a greater relation with the Caribbean strains than with those from Japan.

CONCLUSIONS

The presence of HTLV-II subtype has been confirmed among intravenous drug addicts in Spain. Isolation and characterization of the HTLV-I strain demonstrated that this also circulating around Spain despite its South American origin.

Detection of human papillomavirus 16 and 18 DNA in epithelial lesions of the lower genital tract by in situ hybridization and polymerase chain reaction: cervical scrapes are not substitutes for biopsies

Human papillomavirus (HPV) types 16 and 18 in 66 women with histologically documented lesions of the genital tract and 64 control cohorts were investigated. The efficacies of in situ hybridization and polymerase chain reaction (PCR) in detecting HPV 16 and 18 DNA were analyzed. In order to assess the usefulness of replacing biopsies with cervical scrapes, the two samples were compared by PCR. The prevalence rates of HPV infection by PCR were 59.1 and 10.9% in patients and controls, respectively. PCR was three times more sensitive than in situ hybridization (52.6 versus 17.8%). However, the need to improve PCR sensitivity by subsequent dot blot hybridization reduced one of the main advantages of PCR, i.e., expeditious diagnosis. Cervical scrapes were less sensitive than biopsies (13.6 versus 53%), although with four (6.1%) patients with intraepithelial neoplasias, HPV DNA was identified only by means of cervical scraping. We conclude that obtaining biopsy specimens and cervical scraping are complementary sampling procedures.