Diagnosing systemic lupus erythematosus: new-generation immunoassays for measurement of anti-dsDNA antibodies are an effective alternative to the Farr technique and the Crithidia luciliae immunofluorescence test.

The aim of this study was to evaluate the diagnostic performance of four new enzyme immunoassays (EIAs) for anti-double-stranded-DNA (anti-dsDNA) antibodies, in comparison with the Farr assay and the Crithidia luciliae immunofluorescence test (CLIFT). To this purpose, sera from four patient groups were collected: 52 sera from patients with systemic lupus erythematosus (SLE); 28 from patients with other connective tissue diseases (CTD); 36 from patients with hepatitis C virus (HCV) infection; and 24 from those with acute viral infection. All sera were tested for anti-dsDNA antibodies by four EIA methods using a different antigenic DNA source [synthetic oligonucleotide (Method A), circular plasmid (Method B), recombinant (Method C), and purified extracted (Method D)], and by CLIFT and Farr assays. The diagnostic sensitivity of the assays was as follows: 84.6% (Method A), 73% (B), 82.7% (C), 84.6% (D), 55.8% (CLIFT), and 78.8% (Farr). Specificity was 82.9% (A), 97.7% (B), 96.5% (C), 94.3% (D), 96.5% (CLIFT), and 90.9% (Farr). From these data, we can conclude that the new-generation EIA methods evaluated in this study have higher sensitivity than the CLIFT and Farr assays and, with the exception of Method A, have specificity similar to the CLIFT and slightly higher than the Farr assay. These findings suggest that EIA tests may replace CLIFT as a screening test and the Farr assay as a specific test, for anti-dsDNA antibody detection.

Accuracy of semiquantitative immunoenzymatic methods in quantitation of anti-topoisomerase I (Scl-70) antibodies.

Reports of a possible correlation between anti-Scl-70 antibody concentration and clinical manifestations in systemic sclerosis patients have recently appeared in the scientific literature. The goal of our study was to evaluate, by means of a multicenter study, the analytical reliability of immunoassay systems in the quantitative measurement of Scl-70 antibodies. Three blind samples (H, M, L) at different anti-Scl-70 antibody concentrations, and a low concentration antibody serum (LPC) used as a common calibrator, were sent three times in a 6-month time span to 39 Italian clinical laboratories. Each laboratory was asked to calculate dosages following the enzyme-linked immunosorbent assay (ELISA) method they used and report the optical density values of each sample (ODs), of the cutoff serum provided by the manufacturer of the kit used (ODco) and of LPC (ODLPC). The overall analytical imprecision (between methods and between laboratories) of the three different determinations of the values respectively expressed in ODs, ODs/ODco and ODs/ODLPCratio was 47.1, 52.8 and 34.0% for sample H, 56.2, 47.4% and 34% for sample M and 84.6, 86.0 and 86.6% for sample L. The average intra-method analytical imprecision was, respectively, 20.7, 29.8 and 18.6% for sample H, 24.6, 26.5 and 19.3% for sample M, and 30.6, 28.1 and 20.2% for sample L. The commercial ELISA methods currently used to determine the presence of anti-Scl-70 autoantibodies show considerable differences in the quantitative determination. The best results for reproducibility analyses have been obtained when the values were expressed as a ratio between the ODs of the sample and of the common calibrator (ODs/ODLPC). Forward-looking clinical studies that can clarify the usefulness of quantitative determination of anti-Scl-70 antibodies in the monitoring of diffuse scleroderma patients can be performed only when standard serum with a known antibody concentration and calibration curves for quantitative ELISA measurements are made available.

Bone quality in perinatally HIV-infected children: role of age, sex, growth, HIV infection, and antiretroviral therapy.

Appropriate supportive care and identification of long-term sequels of therapy are of paramount importance in HIV-infected pediatric patients. As low bone mineral quality (BMQ) in patients can be considered a marker of possible degeneration in osteopenia and osteoporosis in adulthood, we evaluated bone features in a pediatric population. Forty-four patients (23 females, 21 males; aged 3-17 years) were compared with a control population (1227 healthy children: 568 females, 641 males; aged 3-18 years). Seven patients were CDC stage C, 18 B, and 18 A. All patients were vertically infected; four were naive to any antiretroviral treatment, seven were taking two NRTIs, and 32 were on HAART. BMQ was assessed by a quantitative ultrasound (QUS) technique. It measures the amplitude-dependent speed of sound (AD-SoS, m/sec) and the bone transmission time (BTT, microsec). QUS values were significantly lower in cases than in controls, even after adjustment for age and body size (AD-SoS: 1924.7 +/- 64.9 and BTT: 0.97 +/- 0.3 in controls; AD-SoS: 1879.7 +/- 57.2 and BTT: 0.80 +/- 0.32 in cases; p < or = 0.001). The associations of AD-SoS and BTT with gender, type of therapy, and CDC stages were not significant. AD-SoS and BTT were significantly associated with age (r = 0.59, p < 0.0001), skeletal age SDS (r = 0.46, p = 0.002), height (r = 0.66, p < 0.0001), and therapy duration (r = 0.31, p = 0.04). Both AD-SoS and BTT values in patients fell below mean values of controls. Follow-up of bone mineral density is important in patients to prevent long-term problems of skeletal status.

Drug-resistant tuberculosis in HIV-infected persons: Italy 1999-2000.

BACKGROUND: Patients with HIV infection may be a valuable target for assessing the impact of drug-resistant tuberculosis (TB). PATIENTS AND METHODS: An observational, prospective study was conducted in 96 infectious disease hospital units in Italy during 1999-2000. A total of 140 HIV-infected patients with diagnosis of TB and with an isolate tested for drug susceptibility entered the analysis. Drug resistance (DR) was defined as resistance to either isoniazid (INH) or rifampin (RIF), while multidrug resistance (MDR) was defined as resistance to INH and RIF. RESULTS: A total of 117 (83.6%) episodes of TB were classified as new cases and 23 (16.4%) as previously treated cases. Prevalence of resistance to INH or RIF was 12.8% and 4.3% among new cases, and 17.4% and 26.1% among previously treated cases, respectively. Prevalence rates of DR and MDR were 14.5% and 2.6% among new cases and 30.4% and 12.5% among previously treated cases, respectively. No statistically significant risk factors associated with DR or MDR TB emerged in this analysis. CONCLUSION: High prevalence rates of DR and MDR are present among HIV-infected TB patients in Italy, in particular among previously treated cases.

Pharmacokinetics and pharmacodynamics of nelfinavir administered twice or thrice daily to human immunodeficiency virus type 1-infected children.

We studied the pharmacokinetics and pharmacodynamics of nelfinavir administered 2 or 3 times per day to human immunodeficiency virus type 1 (HIV-1)-infected children receiving highly active antiretroviral therapy containing nelfinavir. The geometric mean trough concentrations of nelfinavir for the thrice- and twice-daily regimens were 1.55 mg/L and 1.11 mg/L, respectively (P=not significant). Nelfinavir concentrations did not correlate with total daily dose, dose per kilogram of weight, age, weight, previous protease inhibitor (PI) experience, or CD4(+) cell percentage. In the 25 PI-naive children, the virus load reductions at 24 weeks of treatment with the twice- and thrice-daily regimens were comparable. A significantly higher percentage of children in the twice-daily group had a trough concentration of nelfinavir of less than the inhibitory concentration of 95% (P=.042). The decrease in the virus load at 24 weeks of treatment was not correlated with the trough concentration of nelfinavir. The variability of trough concentrations was extremely high, particularly among recipients of the twice-daily regimen, resulting in a higher number of patients with subinhibitory concentrations of nelfinavir in this group.

IgA and IgG tissue transglutaminase antibody prevalence and clinical significance in connective tissue diseases, inflammatory bowel disease, and primary biliary cirrhosis.

An association between celiac disease (CD) and other autoimmune diseases such as connective tissue diseases (CTD), inflammatory bowel diseases (IBD), and primary biliary cirrhosis (PBC) has been reported in several studies. However, a high rate of false positives in autoantibody testing was noted, especially when tissue transglutaminase (tTG) from guinea pig liver was used. Thus, the real prevalence of CD in CTD, IBD, and PBC is unclear. In a case-control study, 400 patients with CTD, 170 with IBD, 48 with PBC, and 120 healthy subjects were investigated for CD by the analysis of IgA and IgG tTG antibodies using the more specific human recombinant tTG immunoenzymatic assay. Patients and controls with positive findings were further tested for antiendomysial antibodies by indirect immunofluorescence and HLA typing, and those found positive by either of these tests underwent duodenal biopsy to confirm a possible diagnosis of CD. Twelve patients were positive for IgA or IgG tTG antibodies, showing an overall prevalence of 1.9%. Only 1 healthy subject (0.8%) had a low level positive reaction for IgA anti-tTG. Among the 12 patients and the healthy subject, only 2 (1 SLE and 1 ulcerative colitis patient) were subsequently confirmed to be affected with CD by positive EMA, HLA, and small bowel biopsy findings. The highest rate of false positives was found in PBC patients (10.4%). For these reasons, serological screening testing for CD is not recommended in CTD patients or in subjects affected with IBD or PBC, unless there is a relevant clinical suspicion of CD.

Gram-positive bacterial resistance. A challenge for the next millennium.

Penicillin G was first used in 1941. Since then, the trend in bacterial infections has changed. New antibiotics have been developed and bacterial resistance has spread as a consequence. The spread of Gram positive resistant bacteria is related to an inappropriate use of antibiotics. Antibacterial agents are abused or overused in various fields: medicine itself, veterinary science and zootechnics. Now, at the beginning of the third millennium we have been forced to limit our therapeutic options in order to combat these insidious enemies. Selective antibiotic pressure on the microbial population, notably on enterococci and staphylococci, made these two pathogens recalcitrant to traditional chemotherapy. It is a matter of concern that today, vancomycin-resistant Enterococcus spp. (VRE) and vancomycin-intermediate and resistant Staphylococcus aureus (VISA and VRSA) are now being observed worldwide among emerging pathogens. Most pharmaceutical companies are today developing antimicrobial drugs that are active against Gram-positive bacteria. Quinupristin/dalfopristin and linezolid are the most promising drugs and are available only for serious infections; future agents being developed for multi-resistant Gram-positive infections include daptomycin and the glycyclines, although these are still in the development phase. Nevertheless, our group has had the opportunity to treat some serious infections with these drugs and the good results achieved are reported in this review.

The relationship between ritonavir plasma trough concentration and virological and immunological response in HIV-infected children.

BACKGROUND: We studied a number of factors, including ritonavir plasma levels, and their capability of predicting response to therapy with ritonavir (RTV). METHODS: Eleven HIV-positive children, nucleoside reverse transcriptase inhibitor (NRTI)-experienced, protease inhibitor (PI) naive, receiving RTV in combination with two NRTIs were enrolled in the study. Demographic parameters were: median age (range) 10 (2-13) years, weight 26 (10-38) kg, body surface area (BSA) 0.93 (0.47-1.21) m(2). Baseline values of CD4, percent CD4 and viral load were 137 (2-1390) cells/microL, 9.5 (0.4-32.4)%, and 5.15 (4.30-6.18) log10 copies/mL, respectively. The dose of RTV was 318 (266-409) mg/m(2) twice daily. Peak (3.5 h after administration) and trough (predose) plasma concentrations of RTV were determined on one occasion at steady-state after a morning dose. Virological response to treatment was quantified as the difference between the baseline value of viral load and the value observed at 6 months of therapy (Delta(6)). RESULTS: The relationship between Delta(6) and demographic parameters (age, weight, BSA, and baseline CD4, percent CD4, and viral load) and plasma concentrations of RTV was studied by linear regression. Median (range) Delta(6) was 0.88 (0.77-2.62) log10 copies/mL. Peak and trough of RTV were 14.9 (3.2-31.4) and 5.0 (0.1-15.6) mg/L, respectively. Trough concentration of RTV was the best predictor of Delta(6), although the relationship between these two variables was not statistically significant (r = 0.56, P = 0.075). CONCLUSION: Our observation of a trend for a greater decrease in viral load in patients with higher trough concentration of RTV warrants further pharmacodynamic studies of PI in paediatric patients.

Adherence to combination antiretroviral treatment in children.

PURPOSE: To assess the level of nonadherence to combination antiretroviral therapy of HIV-infected children and to identify the main problems faced by caregivers when giving medicines to children. METHOD: A questionnaire was administered to the caregivers of HIV-infected children who were under combination antiretroviral treatment and were followed at our institution. RESULTS: We evaluated 44 children (mean age, 9.4 years); 13 were treated with a two-drug regimen, 30 with a three-drug regimen, and 1 with a four-drug regimen. Each child received a mean of 8.1 pills and/or syrup doses. In 54.5% of treatments, food restrictions were necessary. The mother was the main person giving medicines to the child (56.8%). A complete written schedule of the child's treatment was present in 50% of families. About 20.5% and 31.8% of children had missed at least one dose of antiretroviral drugs in the last 3 days before assessment and since last visit (1-2 months earlier), respectively. Main problems reported by caregivers were: (a) too many medicines/ pills (34%); (b) difficulty in swallowing pills (29.5%); (c) taking medicines at school or out of home (27.3%); (d) child resisting/refusing therapy/spitting out (25%); and (e) food interactions (22.7%). CONCLUSION: The observed high level of nonadherence was similar to what was reported by other pediatric studies. Specific interventions aimed at improving compliance in pediatric patients were identified: improvement of anti-HIV drug formulations, better counselling for children and their families, and tailoring of antiretroviral treatment. However, caution is necessary in generalizing our results due to the small sample size and to the heterogeneity of the cohort.

The effect of formulary restriction in the use of antibiotics in an Italian hospital.

OBJECTIVE: To compare the expenditure and usage of antibiotics at the San Martino Teaching Hospital, a 2500-bed hospital in Genoa, Italy, before and after the implementation of an antibiotic control program that streamlined the hospital formulary and the creation of a restricted group of antibiotics requiring approval before use. METHODS: Usage and expenditure data for all antibiotics were collected from 1996 to 1998. Antibiotic usage was standardised by defined daily doses (DDDs) per 100/patient-days. Cost data were expressed in Euros. Changes in antibiotic usage was determined by comparing the mean usage during 1996 and 1997, the period before the implementation of the antibiotic control program, to 1998 when the streamlined formulary and restricted group of antibiotics, controlled by the Infectious Disease Team (IDT). were initiated. The Wilcoxon rank sign test was used to determine statistical significance of the changes in overall antibiotic use; a P value of less than 0.05 was considered significant. RESULTS: After the implementation of the antibiotic control program, overall antibiotic usage decreased by 8.5%, 28.00 DDD/100 patient-days during 1996-1997 to 25.62 DDD/100 patient-days during 1998. The control program resulted in overall savings of 342,927 Euros after the first year of implementation. The usage and expenditure in the restricted group of antibiotics decreased by 78.5% and 53.5%, respectively, (P=0.03). Restricting the use of ceftazidime and imipenem accounted for the majority of the decreased usage and savings. In the non-restricted group of antibiotics, usage increased only by 32.6% resulting in a net reduction of 46.3% in all antibiotic use. CONCLUSION: Although antibiotic control programs have been successful in other countries, this represents the first attempt at successful antibiotic control in a large Italian teaching hospital. Streamlining the formulary to control antibiotic choices and the creation of a restriction program using the expertise of infectious disease physicians resulted in significant reductions in the use of and expenditure for antibiotics.

Linezolid treatment of prosthetic hip Infections due to methicillin-resistant Staphylococcus aureus (MRSA).

Prosthetic joint infection is an infrequent but serious complication of total joint arthroplasty. Complete removal of all foreign material is essential, however when prosthesis removal is not possible or contraindicated, suppressive antibiotic therapy with retention of the functioning hip arthroplasty may be considered. Linezolid, the first approved oxazolidinone, appears to be a promising new agent for the treatment of serious Gram-positive infections. We report two cases of Methicillin-resistant Staphylococcus aureus (MRSA) prosthetic hip infections successfully treated with a long course of linezolid. This observation suggest that linezolid is a promising drug for the treatment of prosthetic joint infections due to MRSA or other Gram-positive pathogens, particularly when other therapeutic approaches are not feasible or a long-term antibiotic therapy is required.

Puberty in perinatal HIV-1 infection: a multicentre longitudinal study of 212 children.

OBJECTIVE: To define age at entry into Tanner stages in children with perinatal HIV-1 infection. DESIGN: Multicentre longitudinal study including 212 perinatally HIV-1-infected children (107 girls and 105 boys) followed-up during puberty (from 8 and 9 years onwards in girls and boys, respectively). Healthy children (843 girls and 821 boys) provided reference percentiles. P2 or B2 stages in girls and P2 or G2 stages in boys defined onset of puberty. METHODS: The cumulative probability [95% confidence limit (CI)] of entry into each stage at different ages was estimated by the Kaplan-Meier product-limit method; differences were evaluated by log rank test. Relationships were tested using the Spearman's rank correlation coefficient. RESULTS: Ages of girls [years (95%CI)] at P2 [12.9 (12.6-13.2)], P3 [13.4 (13.0-13.8)], P4 [14.6 (14.0-15.2)], B2 [12.7 (12.2-13.2)], B3 [13.3 (12.8-14.0)] and B4 [14.6 (14.0-15.2)] stages were > 97th percentile (> or = 21 month delay) of controls. Ages of boys [years (95%CI)] at P2 [12.6 (12.1-13.1)], P3 [13.9 (13.4-14.4)], P4 [14.9 (14.2-15.6)], G2 [12.1 (11.5-12.7)], G3 [13.6 (13.1-14.1)] and G4 [14.9 (14.1-15.7)] stages were at the 75-97th percentiles (< or = 15 month delay). Age at onset of puberty was not related to clinical and immunological condition, antiretroviral treatment, weigh for height and age at onset of severe disease or immune suppression. CONCLUSION: Perinatal HIV-1 infection interferes with sexual maturation. The mechanisms by which this occurs should be elucidated and intervention strategies designed. Intervention could save much psychological distress, since associated linear growth failure can exacerbate adolescents' feelings of being different and unwell.

The organization of infection control in Italy.

This paper describes the organization of infection control in Italy with respect to regulatory requirements, the tasks and training of the infection control physician and nurse, and the function and responsibilities of the infection control committee. Moreover, the paper reports on incidence and prevalence of hospital-acquired infections (HAI), antibiotic usage and antimicrobial resistance in Italy.

Impact of an antimicrobial formulary and restriction policy in the largest hospital in Italy.

We have analysed the expenditure on antimicrobial drugs in the largest hospital in Italy; over this period, a committee prepared an antibiotic policy document. This formulary lists all antimicrobial drugs available in the hospital. Some drugs were removed from the list and others are only available on special request for a named patient. In the hope of optimising drug utilisation, we included all the reasons for the choice of agent in the document. The introduction of this formulary resulted in an immediate saving and perhaps in the future we shall also observe an improvement in bacterial resistance patterns.

Does HGV-HIV co-infection exist?

Hepatitis G virus (HGV) is a recently discovered virus belonging to the Flaviviridae family. Prevalence of HGV active infection (presence of HGV-RNA) in HIV-1-infected patients has been reported in various categories of patients. Our study aimed to find out its prevalence in our cohort of HIV-1-infected children. No investigated child presented with signs of HGV active infection notwithstanding the presence of many risk factors for HGV infection. Prevalence of HGV active infection in our cohort was <2.7%.