Luigi Ortona

Value of Combined Approach With Thallium-201 Single-Photon Emission Computed Tomography and Epstein-Barr Virus DNA Polymerase Chain Reaction in CSF for the Diagnosis of AIDS-Related Primary CNS Lymphoma

PURPOSE To determine the diagnostic capability of thallium-201 (201Tl) single-photon emission computed tomography (SPECT) combined with Epstein-Barr virus DNA (EBV-DNA) in CSF for the diagnosis of AIDS-related primary CNS lymphoma (PCNSL). PATIENTS AND METHODS All human immunodeficiency virus (HIV)-infected patients with focal brain lesions observed between June 1996 and March 1998 underwent lumbar puncture and 201Tl SPECT. Each CSF sample was tested with polymerase chain reaction (PCR) for EBV-DNA. RESULTS Thirty-one patients were included, 13 with PCNSL and 18 with nontumor disorders. In 11 PCNSL patients, EBV-DNA was positive. Thallium-201 uptake ranged from 1.90 to 4.07 in PCNSL cases (mean, 2.77; 95% confidence interval [CI], 2.35 to 3.19) and from 0.91 to 3.38 in nontumor patients (mean, 1.62; 95% CI, 1.30 to 1.94) (P<.0002). Using a lesion/background ratio of 1.95 as cutoff, a negative SPECT was found in one PCNSL case and 16 nonneoplastic cases. A cryptococcoma and a tuberculoma showed highly increased 201Tl uptake. Epstein-Barr virus DNA was never detected in nonneoplastic patients. For PCNSL diagnosis, hyperactive lesions showed 92% sensitivity and 94% negative predictive value (NPV), whereas positive EBV-DNA had 100% specificity and 100% positive predictive value. The presence of increased uptake and/or positive EBV-DNA had 100% sensitivity and 100% NPV. CONCLUSION Combined SPECT and EBV-DNA showed a very high diagnostic accuracy for AIDS-related PCNSL. Because PCNSL likelihood is extremely high in patients with hyperactive lesions and positive EBV-DNA, brain biopsy could be avoided, and patients could promptly undergo radiotherapy or multimodal therapy. On the contrary, in patients showing hypoactive lesions with negative EBV-DNA, empiric anti-Toxoplasma therapy is indicated. In patients with discordant SPECT/PCR results, brain biopsy seems to be advisable.

Evaluation of cerebrospinal fluid EBV-DNA and IL-10 as markers for in vivo diagnosis of AIDS-related primary central nervous system lymphoma

Summary. Acquired immunodeficiency syndrome (AIDS)‐related primary central nervous system lymphoma (PCNSL) is almost always associated with the Epstein‐Barr virus (EBV), and EBV‐DNA in cerebrospinal fluid (CSF) has been indicated as a useful tumour marker for this HIV‐related neoplasm. AIDS lymphomas also show an enhanced production of IL‐10 which is generally associated with the presence of EBV in lymphoma cells.

Discontinuation of primary prophylaxis for Pneumocystis carinii pneumonia and toxoplasmic encephalitis in human immunodeficiency virus type i-infected patients: The changes in opportunistic prophylaxis study

A multicenter open, randomized, controlled trial was conducted to determine whether primary prophylaxis for Pneumocystis carinii pneumonia and toxoplasmic encephalitis can be discontinued in patients infected with human immunodeficiency virus type 1 (HIV-1) whose CD4+ T cell counts have increased to >200 cells/mm3 (and who have remained at this level for at least 3 months) as a result of highly active antiretroviral therapy (HAART). Patients were randomized to either the discontinuation arm (i.e., those who discontinued prophylaxis; n=355) or to the continuation arm (n=353); the 2 arms of the study were similar in terms of demographic, clinical, and immunovirologic characteristics. During the median follow-ups of 6.4 months (discontinuation arm) and 6.1 months (continuation arm) and with a total of 419 patient-years, no patient developed P. carinii pneumonia or toxoplasmic encephalitis. The results of this study strongly indicate that primary prophylaxis for P. carinii pneumonia and toxoplasmic encephalitis can be safely discontinued in patients whose CD4+ T cell counts increase to >200 cells/mm3 during HAART.

Central venous catheter-related sepsis in a cohort of 366 hospitalised patients

Five hundred two central venous catheters inserted in 366 patients were evaluated prospectively over a one-year period to determine the frequency and risk factors associated with catheter-related sepsis. For study purposes, in cases in which catheter infection was suspected but the initial blood cultures were negative, the catheters were replaced by guidewire technique; otherwise, the catheters were routinely changed after 21 days by guidewire technique. A catheter-related infection was suspected in 190 cases (190/502, 38%). A diagnosis of catheter-related sepsis was established in 50 patients, which represents 10% of the total number of lines (502). Over a total of 6428 days of catheter use, the infection rate was 0.8 cases of sepsis per 100 catheter-days.Staphylococcus epidermidis, Staphylococcus aureus, andCandida spp. were the most frequently isolated aetiological agents of sepsis. On univariate analysis, six variables affecting the rate of catheter-related sepsis were identified: neutropenia for more than eight days (p<0.001); AIDS (p<0.001); haematological malignancy (p<0.001); administration of total parenteral nutrition (p=0.001); duration of site use (p=0.04); and high APACHE II score (p=0.04). The logistic regression analysis revealed that AIDS and haematological malignancies were independent risk factors of catheter-related sepsis. Catheter replacement over a guidewire was no more likely to be associated with sepsis than was percutaneous catheter insertion. In conclusion, although the incidence of established catheter infection is much lower than the incidence of suspected infection, in most cases of suspected infection it is wise to change the catheter with the guidewire technique and wait for culture of the tip, rather than to remove the catheter immediately. Such a policy may help reduce the number of unnecessary catheter removals.

The impact of bacteraemia on HIV infection. Nine years experience in a large Italian University Hospital

The object of this case control study was to evaluate the frequency, the risk factors, the microbiological spectrum and the outcome of 249 cases of bacteraemia observed in 209 HIV-infected patients, most them affected by AIDS. The rate of bacteraemia in the total yearly HIV-related admissions increased from 4% in 1985 to 13% in 1993. The more common aetiological agents of bacteraemia were: Staphylococcus aureus (29.7%), non-typhoidal species of Salmonella (14.1%), Staphylococcus epidermidis (10.9%), Streptococcus pneumoniae (8.4%) and Pseudomonas aeruginosa (7.6%). A mixed flora was found in 14% of the episodes. Multivariate analysis of predisposing factors indicated that a low CD4+T-cell count (<0.2 x 10(9)/l) (P=0.01), use of central venous catheters (CVC) (P=0.01) and neutropenia (polymorphonuclear neutrophils <1.0 x 10(9)/l) (P=0.04) were independent risk factors for the development of bacteraemia. Logistic regression did not reveal any association of bacteraemia with intravenous drug abuse (on univariate analysis P=0.04). The response (31.8%). Recurrences to specific therapy was favourable in 170 episodes (68.2%); death occurred in 79 (31.8%). Recurrences arose in 40 patients, 17 (42.5%) of them died. The outcome of bacteraemia was influenced by a low number of CD4+T-cells (P<0.001) but not of polymorphonuclear cells. Our findings suggest that bacteraemia is a relatively common event in HIV-infected patients, especially under particular conditions (e.g. intravenous drug abuse, use of CVC, neutropenia and a low CD4-T-cell count). It requires special attention from physicians who must recognise and treat the condition promptly at an early stage.

Correlates of independent HIV-1 replication in the CNS and of its control by antiretrovirals

ObjectiveTo investigate in detail factors associated with independent replication of HIV-1 in CNS, and to predict its therapeutic control. MethodsHIV RNA concentration was measured by PCR in 134 cross-sectional paired plasma and CSF samples from 95 patients infected with HIV-1 with various conditions, and in longitudinal CSF samples from 50 patients on antiretroviral treatment. Monocyte chemotactic protein (MCP)-1 was quantified in CSF by ELISA. ResultsHigh HIV RNA levels either in plasma or in CSF did not correlate with HIV RNA concentration in the paired biologic sample. A high CSF-to-plasma HIV RNA ratio, suggesting independent viral replication in the CNS, was associated with higher CSF viral load and higher CSF MCP-1 levels. Higher MCP-1 levels in the CSF were also associated with neurologic disorders and were not influenced by the use of highly active antiretroviral therapy (HAART). A higher number of antiretroviral drugs with CSF penetration correlated with a more profound CSF HIV-1 load reduction, independently from the use of HAART alone. Virologic suppression in CSF was predicted by a higher number of CSF-penetrating antiretrovirals and by the baseline CSF viral load, whereas lower baseline CD4 counts and higher MCP-1 levels were associated with increased risk of virologic failure. ConclusionsQuantification of HIV RNA in CSF is clinically useful, particularly in patients with neurologic disorders. CSF penetration of antiretrovirals must be considered when choosing treatments, mainly in patients with higher CSF viral loads, advanced disease, and CNS disorders associated with significant macrophage activation.

bacterial Pneumonia in Hiv-infected Patients : analysis of Risk Factors and Prognostic Indicators

This case control study assessed risk factors and prognostic indicators of 350 episodes of bacterial pneumonia in 285 HIV-infected patients. On univariate analysis, intravenous drug abuse (i.v.DA; p < .001 versus controls), regular cigarette smoking (p < .001), cirrhosis (p = .04), and history of a previous episode of pneumonia (p = .04) were risk factors for community-acquired episodes of bacterial pneumonia, whereas length of hospitalization (p = .01) was a risk factor only for nosocomial bacterial pneumonia. The small amount of circulating T CD4+ cells (<100/ mm3) was a risk factor in both groups of pneumonia (p < .05). Stepwise logistic regression analysis revealed that i.v.DA in community-acquired episodes and low levels of circulating T CD4+ cells, both in community-acquired and hospital-acquired episodes, were independent risk factors for the development of bacterial pneumonia. The case-fatality rate observed in our study was 27%. On stepwise logistic regression analysis, T CD4+ cell counts < or = 100/mm3 (p = .02), neutropenia (p = .04), PO2 arterial level < or = 70 mm Hg (p = .01), and Karnofsky score < or = 50 (p = .04) were independent indicators of mortality. According to a personally developed prognostic score, 211 episodes of pneumonia (60%) were classified as mild, 63 (18%) as moderate, and 76 (22%) as severe. Clinicians must carefully evaluate those variables that can influence the prognosis of bacterial pneumonia to make early identification of affected patients and to promptly establish the most appropriate therapeutic strategy in each case.

Haemopoietic CD34+ progenitor cells are not infected by HIV-1 in vivo but show impaired clonogenesis

Summary. We evaluated the role of CD34 + bone marrow progenitor cells in vivo, in the pathogenesis of AIDS‐related haematological abnormalities. The clonogenic activity of CD34+ cells from seven patients with HIV‐1 infection, without bone marrow involving opportunistic infections or neoplasms, was assessed in semisolid cultures. The number of CFU‐GM was significantiy reduced as compared to the controls (P=0.017). independently from myelotoxic therapy, while the number of BFU‐E was not. The presence of retroviral sequences in CFU‐GM colonies from four patients and in the total population of CD34 + cells from six patients with advanced stage HIV infection was investigated using the polymerase chain reaction. The presence of HIV‐1 sequences was also searched for in a purified suspension of CD34 + cells after 3 weeks liquid culture. All these cells were always HIV‐1 negative, while viral sequences were always detected in bone marrow mononuclear cells from these and other patients. The number of HIV‐1 DNA copies decreased with increasing enrichment. At most 1:10000 CD34+ cells are infected in vivo. Other mechanisms than direct viral infection of progenitor cells must account for the defective haemopoiesis in HIV‐1 infected patients.

Aerosolized pentamidine, cotrimoxazole and dapsone-pyrimethamine for primary prophylaxis of Pneumocystis carinii pneumonia and toxoplasmic encephalitis

ObjectiveTo investigate the efficacy and safety of three regimens for primary prophylaxis of Pneumocystis carinii pneumonia (PCP) and toxoplasmic encephalitis (TE) and to evaluate their effect on survival in patients with HIV infection. DesignRandomized, open label, prospective trial. SettingA single Infectious Diseases Department in Italy. PatientsHIV-infected patients (n = 197) with a CD4 count < 200 × 106/l and without previous PCP or TE. InterventionsPatients were randomly assigned to receive (1) aerosolized pentamidine (AP; 300 mg monthly), (2) cotrimoxazole (CTX; 160 mg trimethoprim and 800 mg sulfamethoxazole every other day), or (3) dapsone-pyrimethamine (DP; 100 mg weekly dapsone and 25 mg biweekly pyrimethamine). Main outcome measuresPCP, TE, death, and drug-limiting toxicity. Considering difference in PCP occurrence the trial was interrupted on June 1992. Observation was prolonged until June 1994 for TE and survival. ResultsIntention-to-treat analysis yielded PCP rates of 10.2 per 100 person-years in the AP, 2.0 in the CTX, and 32.1 in the DP group [adjusted relative risk of DP versus CTX: 17.5; 95% confidence interval (CI), 2.2–139.6; P = 0.007]. TE rates in patients with positive Toxoplasma serology were 25.6 per 100 person-years in the AP, 8.9 in the CTX and 9.4 in the DP group. In ‘on treatment’ analysis, no episode of TE developed in the DP group, and rates were 34.7 per 100 person-years in the AP and 2.5 in the CTX group (AP versus CTX: P = 0.01; AP versus DP: P = 0.004). The adjusted risk of mortality for the DP group was 2.8 times that of the CTX group in the first part of the study (95% CI, 1.1–7.3; P = 0.037), and 1.8 times (95% CI, 1.1–2.9; P = 0.02) in the prolonged follow-up. No significant difference in the occurrence of serious adverse reactions was observed between the three treatment groups. ConclusionsIntermittent CTX was more effective than low-dose DP and showed a slight but not significant advantage on AP for primary PCP prophylaxis. DP was associated with a shorter survival. Both CTX and DP resulted in a significant reduction in the risk of TE.

The natural history of HIV infection in intravenous drug users: risk of disease progression in a cohort of seroconverters.

A multicentre cohort study was carried out to estimate the incidence of AIDS and HIV-related conditions in newly infected intravenous drug users (IVDU). The enrollment criteria included the identification of the seroconversion time. Two hundred and five subjects entered the study, and were followed for a mean of 26 months. Twelve subjects developed clinical AIDS over a 4-year period. The actuarial incidence of AIDS estimated by Kaplan-Meier survival technique was 17.8% by 4 years since seroconversion. The risk of developing AIDS increased significantly after 24 months from seroconversion. Relatively small figures accounted for the lack of statistical association between the risk factors investigated and the disease status.