Diagnosis of Pneumocystis pneumonia by real-time PCR in patients with various underlying diseases

BackgroundPneumocystis pneumonia (PCP) is a disease caused by the opportunistic infection of the fungus Pneumocystis jirovecii. Several PCR methods have been developed to aid in the diagnosis of PCP. In this study, we evaluated the performance of a real-time PCR in the diagnosis of PCP, in patients with various underlying diseases.MethodsNinety-seven BAL samples and 94 sputum samples from 191 patients were used in the study. Patients were classified as PCP (121 patients) or non-PCP (70 patients) based on their clinical and radiological presentations.ResultsReal time PCR amplified the P. jirovecii mitochondrial large-subunit rRNA gene with a detection limit of 68 copies of DNA per reaction. Non-PCP pathogens including 32 different fungi and bacteria were also evaluated. Overall, 71.9% of the samples from PCP patients and 14.5% of those from non-PCP patients were positive for the PCR test with a C_T value of the real-time PCR below 45. The main underlying diseases of the patients were hematological or solid malignancies (47.1%) and HIV infection (8.9%). The C_T values of the test were significantly lower in BAL samples from PCP patients than those from non-PCP patients (p = 0.024). No non-PCP patient had a C_T value below 30, whereas samples from 24.8% of PCP patients with underlying diseases had a C_T value below 30.ConclusionSince false positive PCR results were obtained, perhaps due to colonization, we suggest that the diagnosis of PCP should be based on a combination of clinical symptoms, underlying diseases, and PCR results.     

Partner concordance in reports of joint risk behaviors

OBJECTIVE: To evaluate the accuracy of self reports on sexual and drug use behaviors. METHODS: Data from a network study of HIV transmission among a sample of drug users and nonusers are used to compare reports of sexual and drug use behaviors by partners who engaged in those behaviors. Partner concordance (self-report agreement between two people) was used as an estimate of validity. RESULTS: Results showed that persons are able to recall and report about 85% of their recent partners (15%-20% less for recent drug use partners). For relationships that were reported by both partners, a high degree of concordance existed about recent behaviors (83%-96%) and variable agreement about frequency (0.48 相似文献   

Development and evaluation of a quantitative, touch-down, real-time PCR assay for diagnosing Pneumocystis carinii pneumonia

A rapid (time to completion, <4 h, including DNA extraction) and quantitative touch-down (QTD) real-time diagnostic Pneumocystis carinii PCR assay with an associated internal control was developed, using fluorescence resonance energy transfer (FRET) probes for detection. The touch-down procedure significantly increased the sensitivity of the assay compared to a non-touch-down procedure. Tenfold serial dilutions of a cloned target were used as standards for quantification. P. carinii DNA has been detected in respiratory specimens from patients with P. carinii pneumonia (PCP) and from patients without clinical evidence of PCP. The latter probably represents colonization or subclinical infection. It is logical to hypothesize that quantification might prove helpful in distinguishing between infected and colonized patients: the latter group would have lower copy numbers than PCP patients. A blinded retrospective study of 98 respiratory samples (49 lower respiratory tract specimens and 49 oral washes), from 51 patients with 24 episodes of PCP and 34 episodes of other respiratory disease, was conducted. PCR-positive samples from colonized patients contained a lower concentration of P. carinii DNA than samples from PCP patients: lower respiratory tract samples from PCP and non-PCP patients contained a median of 938 (range, 2.4 to 1,040,000) and 2.6 (range, 0.3 to 248) (P < 0.0004) copies per tube, respectively. Oral washes from PCP and non-PCP patients contained a median of 49 (range, 2.1 to 2,595) and 6.5 (range, 2.2 to 10) (P < 0.03) copies per tube, respectively. These data suggest that this QTD PCR assay can be used to determine if P. carinii is present in respiratory samples and to distinguish between colonization and infection.     

免疫组化和GMS染色对AIDS合并肺孢子菌肺炎的临床诊断价值

目的 探讨免疫组化及六胺银(gomori's methenamine silver nitrate stain,GMS)染色法对AIDS合并肺孢子菌肺炎(pneumocystis pneumonia,PCP)的临床诊断价值.方法 选择50例临床确诊为合并PCP的AIDS患者作为实验组(PCP组)、25例非PCP的呼吸道感染患者作为对照组,分别采用单克隆抗体免疫组化法和GMS染色法对两组患者的支纤镜肺活检标本进行肺孢子菌(pneumocystis jiroveri,Pj)检测,并比较两种方法的敏感性和特异性.结果 免疫组化法检测Pj的敏感性为66%(33/50),特异性为100%(25/25);GMS染色法检测Pj的敏感性为42%(21/50),特异性为92%(23/25).结论 免疫组化法检测Pj的敏感性和特异性均高于GMS染色法,这将有助于提高Pj的检出率及PCP的确诊率.     

Recreational use of 3,4-methylenedioxymethamphetamine (MDMA) or 'ecstasy': evidence for cognitive impairment

BACKGROUND: It has recently been shown that 3,4-methylenedioxymethamphetamine (MDMA) or 'ecstasy' causes long-lasting alterations to brain structure and function in animals, and there is mounting evidence that recreational users of the drug show impairments in some aspects of cognitive functioning including memory for verbal information. The present study investigates possible effects on other cognitive functions and explores the temporal course of development and resolution of these impairments by comparing novice, regular and abstaining users with a matched group of non-users. METHODS: Eighty participants categorized as non-users, novice users, regular users or currently abstinent users of MDMA were assessed on tests of verbal IQ, reversed digit span, immediate and delayed recall of a prose passage and of a complex geometric figure and verbal fluency. RESULTS: The four groups were well-matched for verbal IQ and on demographic variables. They differed in frequency of cannabis use over the last month, but this did not correlate with any cognitive test scores. All three groups of MDMA users showed significantly poorer verbal fluency and immediate and delayed prose recall than non-users. Days since last use and total lifetime consumption of MDMA made separate contributions to the variance in recall scores, accounting jointly for almost half of the variance in delayed recall. By contrast, the groups did not differ on either visual recall or reversed digit span. CONCLUSIONS: The observed deficits provide further evidence of impairments of verbal but not visual memory in MDMA users, and indicate that the deficits are not attributable either to differences in general reasoning ability or to impairment of working memory. The data further suggest that the observed impairments may be attributable to a combination of reversible acute effects of MDMA resolving over a period of 2-3 weeks and more long-term changes associated with extent of lifetime consumption.     

HIV-1 RNA viral load monitoring in HIV-infected drug users on antiretroviral therapy: relationship with outpatient care patterns

HIV-1 viral load (VL) testing is a standard component of HIV care. We examined the use and predictors of VL testing in drug users, a group at risk for problematic care. Using 1996 to 1998 New York State (NYS) Medicaid files, we studied drug users who had been enrolled >10 months, had been prescribed antiretroviral agents in 1997 and 1998, and who had undergone any VL testing in 1997. Our outcome was regular VL testing shown by two or more paid claims for this test in 1998. Patterns of care in 1997 were defined as: regular source of medical care (>35% of visits to one provider), and/or regular drug treatment of >6 months, or neither. We counted visits in 1997 to a provider offering HIV-focused care. Adjusted odds ratios (AORs) of VL testing were assessed. Of 3131 drug users, 73.9% had at least one VL test, whereas 56.2% had two or more VL tests in 1998. The AORs of two or more VL tests were increased for those with regular drug abuse care alone (AOR, 1.50; 95% confidence interval [CI], 1.21-1.84) or with regular medical care (AOR, 1.27; 95% CI, 1.03-1.57) versus those with neither. HIV-focused care was positively associated with two or more VL tests (AOR, 1.38; 95% CI, 1.05-1.81 for 1-3 visits; AOR, 1.94; 95% CI, 1.50-2.51 for four or more visits). We found that nearly half this cohort of drug users did not have regular VL testing. Drug users with HIV-focused care or with regular drug treatment are more likely to have regular VL testing.     

Influence of injection drug use behavior on reported antiretroviral therapy use among women in the HIV Epidemiology Research study: on-site versus referral care

BACKGROUND: HIV-infected injection drug users consistently report poor antiretroviral therapy use and little contact with health care providers. It has been suggested that the clinical setting where patients are seen affects the use of highly active antiretroviral therapy. OBJECTIVES: The purpose of this study was to determine whether ease of access to medical care affects self-report of taking antiretroviral therapy, particularly among female injection drug users. DESIGN: The study is a cross-sectional analysis from a prospective cohort study of HIV-infected women. SETTING: Women were enrolled at four sites in the United States: Detroit, Michigan, and Providence, Rhode Island, where on-site HIV care and treatment were offered, and Baltimore, Maryland, and the Bronx, New York, where all participants were referred elsewhere for HIV care and treatment. PATIENTS: Patients were HIV-infected women with no AIDS diagnosis or women who were at risk for HIV infection either through self-reported injection drug use since 1985 or through sexual contact. MEASUREMENTS: The study measured self-reported use of antiretroviral therapy (ART) alone or combined with Pneumocystis carinii (PCP) prophylaxis in the previous 6 months. RESULTS: In multivariate analysis including type of study site (on-site compared with referral care) and injection drug use, any self-reported ART use associated with low CD4 cell count category, older age, and race. However, at on-site care centers, women were equally likely to report ART use regardless of current, former, or no injection drug use, whereas at referral sites only women identified as sexual contacts were more likely to report any ART use, independent of all other variables. CONCLUSIONS: Easy access to medical care has an important impact on HIV-infected women receiving ART, particularly those who are active injection drug users.     

Natural history of HIV-1 infection and predictors of survival in a cohort of HIV-1 seropositive injecting drug users.

Injecting drug users represent a pivotal and increasing component of acquired immunodeficiency syndrome (AIDS) case reporting in the United States. This article describes the natural history of human immunodeficiency virus (HIV) disease in a New York City cohort of 328 HIV-infected injecting drug users. The study sample of nearly two-thirds men (predominately African Americans and Latino Americans) underwent follow-up from December 1988 through December 1993. Male injecting drug users reported a longer injecting drug use history and were more likely to share needles/works than female injecting drug users. Eighty-nine of 328 study subjects died during the 5 years of observation. Comparing African Americans and Latinos, race/ethnicity was not related to survival. Survival was related to baseline CD4 count and hemoglobin level. Zidovudine use and PCP prophylaxis did not predict survival. Because of the continuing and increasing impact of HIV disease on injecting drug users and communities of color, there remains an unquestionable need to develop effective prevention programs, to understand the natural history of HIV disease, and to develop appropriate therapeutic interventions to treat those with HIV disease.     

Specific effects of ecstasy and other illicit drugs on cognition in poly-substance users

BACKGROUND: A large number of studies, reviews and meta-analyses have reported cognitive deficits in ecstasy users. However most ecstasy users are polydrug users, and therefore it cannot be excluded that these deficits are (partly) the result of drugs other than ecstasy. The current study, part of the Netherlands XTC Toxicity (NeXT) study, investigates the specific sustained effects of ecstasy relative to amphetamine, cocaine and cannabis on the brain using neuropsychological examination. Method: A stratified sample of 67 subjects with such a variation in type and amount of drug use was included that correlations between the consumption of the various drugs were relatively low allowing stepwise linear multiple regression analyses to differentiate between the effects of ecstasy and those of other substances. Subjects were assessed with neuropsychological tests measuring attention, working memory, verbal and visuospatial memory, and visuospatial ability. RESULTS: Ecstasy use [mean 327 (S.D.=364) tablets in lifetime] had a specific significant dose-related negative effect on verbal delayed recall after adjusting for the use of other drugs. CONCLUSIONS: These findings strongly suggest a specific sustained negative effect of ecstasy use on verbal memory. The clinical relevance is not immediately clear, because test performance generally remained within the normal range. However the magnitude of the effect is substantial (d>0.5) and long-term consequences cannot be excluded.     

Phencyclidine in an East Harlem psychiatric population

The use of phencyclidine (PCP) was investigated in the psychiatric population of an East Harlem, New York, hospital. Sixty-eight consecutive PCP-user admissions were interviewed through a 77-item questionnaire. The patient population served by the facility was 48 percent Hispanic and 32 percent black. The sample of PCP users was 86 percent black. This suggests that, in this area, either more blacks use PCP, or nonblack PCP users seek psychiatric help less frequently than black users. This study emphasizes the many problems affecting the sample population and shows evidence that a large portion of the sample is at risk to develop psychiatric symptoms.     

The effects on survival of early treatment of human immunodeficiency virus infection.

BACKGROUND. Zidovudine has been shown to prolong survival in patients with the acquired immunodeficiency syndrome (AIDS) and, in persons with human immunodeficiency virus (HIV) infection but not AIDS, to delay the progression to AIDS. However, it is still uncertain whether treatment before the development of AIDS prolongs survival. METHODS. We analyzed data from a cohort of 2162 high-risk men who were already seropositive for HIV type 1 (HIV-1) and 406 men who seroconverted from October 1986 through April 1991. There were 306 deaths. The probabilities of death were compared among men at similar stages of disease who began zidovudine therapy before the diagnosis of AIDS and among those who did not. Relative risks of death were calculated for each of five initial disease states on the basis of CD4+ cell counts and clinical symptoms and signs appearing over follow-up periods of 6, 12, 18, and 24 months. Adjustments were also made for the use of prophylaxis against Pneumocystis carinii pneumonia (PCP). RESULTS. After we controlled for CD4+ cell count and symptoms, the use of zidovudine with or without PCP prophylaxis before the development of AIDS significantly reduced mortality in all follow-up periods. The relative risks of death were 0.43 (95 percent confidence interval, 0.23 to 0.78) at 6 months, 0.54 (95 percent confidence interval, 0.38 to 0.78) at 12 months, 0.59 (95 percent confidence interval, 0.44 to 0.79) at 18 months, and 0.67 (95 percent confidence interval, 0.52 to 0.86) at 24 months. After we adjusted for the effects of PCP prophylaxis, zidovudine alone significantly reduced mortality at 6, 12, and 18 months (relative risks, 0.45, 0.59, and 0.70, respectively), but not at 24 months (relative risk, 0.81). Among zidovudine users, those who also used PCP prophylaxis before the development of AIDS had significantly lower mortality at 18 and 24 months than those who did not (relative risks, 0.62 and 0.60, respectively). CONCLUSIONS. The results of this study support the hypothesis that in HIV-1 infection, early treatment with zidovudine and PCP prophylaxis improves survival in addition to slowing the progression to AIDS.     

Effectiveness of a real-time PCR for diagnosis of Pneumocystis pneumonia in immunocompromised patients – Experience from a tertiary care center,India

Pneumocystis jirovecii pneumonia (PCP) is a life-threatening fungal infection in immunocompromised patients. Traditionally, the laboratory diagnosis of PCP relied on the visualization of organisms by microscopy as Pneumocystis cannot be readily cultured in the laboratory. The polymerase chain reaction (PCR) method is preferred over the conventional microscopic methods as PCR is rapid and found to have higher sensitivity. This retrospective study aimed to analyze the diagnostic value of a real-time PCR (qPCR) for routine diagnosis of PCP in immunocompromised patients with various underlying conditions. The qPCR targets a 121 bp fragment of P.jirovecii mitochondrial large subunit rRNA gene. The study was conducted in a 2600-bed tertiary care hospital between January and December 2019. All patients whose respiratory samples were tested for PCP by qPCR were included. The clinical diagnosis was made for each patient and categorized into PCP and non-PCP based on multi-component clinical criteria by a multi-disciplinary team. The performance characteristics of qPCR were analyzed using clinical diagnosis as the reference. A total of 339 respiratory samples from 289 patients were tested for PCP by qPCR during the study period. The overall sensitivity and specificity of qPCR were 84.75% (95% CI, 73.01% to 92.78%) and 96.1% (95% CI, 92.7 to 98.2), respectively. The sensitivity was slightly higher among HIV-infected patients (91%) than the non- HIV group (81%). The PCR exhibited higher sensitivity in bronchoalveolar lavage (BAL) (94%) than in sputum samples (81%). The colonization can be ruled out with the cycle threshold (C_T) value of below 34 with a sensitivity and specificity of 100% and 78%, respectively.The real-time PCR showed good sensitivity and specificity for routine diagnosis of PCP in patients with various underlying conditions. In addition, a cut-off C_T value (≤ 34) was determined to exclude colonization from active pneumonia.     

Reduced toxicity with gradual initiation of trimethoprim-sulfamethoxazole as primary prophylaxis for Pneumocystis carinii pneumonia: AIDS Clinical Trials Group 268

Trimethoprim-sulfamethoxazole (TMP/SMX) is recognized as the superior agent for Pneumocystis carinii pneumonia (PCP) prophylaxis but a high incidence of adverse drug reactions, which may be due to toxic drug metabolites, limits its use. AIDS Clinical Trials Group protocol 268 was a randomized, double-blind, controlled two-arm trial designed to determine whether gradual initiation of TMP/SMX suspension reduced the incidence of treatment-limiting adverse drug reactions compared with routine initiation of double-strength (DS; 160 mg/800 mg) tablets. In all, 372 HIV-1-infected study subjects with a CD4+ cell count <250 x 10 cells/mm3 who had not previously received TMP/SMX for PCP prophylaxis were randomized to receive either daily TMP/SMX DS tablets or a gradually increasing dose of TMP/SMX suspension. The suspension dose was increased to reach the equivalent of a DS tablet by study day 13. During the first 2 weeks, study subjects also received a matching placebo tablet/suspension. After week 2, all study subjects received TMP/SMX tablets for the next 10 weeks. There were significantly fewer study subjects who discontinued prophylaxis during the first 12 weeks when TMP/SMX therapy was initiated gradually (17%) than when initiated in DS tablet formulation (33%) (p =.0002). Gradual initiation was also associated with significantly fewer adverse drug reactions. Gradual initiation of TMP/SMX for primary PCP prophylaxis reduces the incidence of its treatment-limiting adverse effects.     

Some aspects of the behavior of young and adult rats treated with p-chlorophenylalanine in infancy

Suckling rats were treated with p-chlorophenylalanine (PCP; 300 mg/kg, 5–15 days of age or 150 mg/kg, 5–21 days) in order to selectively deplete brain 5-hydroxytryptamine (5HT). Some bodily growth retardation occurred during treatment. Although a normal body weight was achieved in adulthood, some stunting of cerebellar growth had occurred. During PCP treatment a reduction in State 2 (paradoxical) sleep occurred at 10 and 14 days of age, without alteration in total sleeping time. Compared with controls, locomotor activity in the open field was reduced only at 22 days of age after prolonged treatment. A marked reduction in turning frequency was evident at 12 and 18 days. Passive-avoidance behavior was facilitated when tested 4–6 days after cessation of PCP. This may represent increased reactivity to a noxious stimulus and is probably dependent on concomitant cerebral 5HT depletion. In adults who received PCP in infancy, brain 5HT concentraton was normal. Learning ability as assessed in the Hebb-Williams maze and passive avoidance in adulthood were not affected. However, a significant degree of hyperactivity was observed in open-field tests.     

Impact of intrauterine exposure to phencyclidine (PCP) and cocaine on neonates.

A total of 505 newborns who were exposed to illicit drugs during intrauterine life were studied to investigate the prevalence, growth parameters, newborn manifestations, and other effects of intrauterine exposure to cocaine and phencyclidine (PCP). The results support the hypotheses that both drugs have serious effects on growth parameters, but this effect was much more pronounced in the cocaine group than in the PCP group. Furthermore, the incidence of borderline microcephalic infants (head circumferences less than the 10th percentile) was much higher in the cocaine group. It also appears that the signs and symptoms observed in both groups are not withdrawal manifestations typically seen in narcotic-exposed infants; rather, these symptoms are true drug effects and should not be considered manifestations of drug withdrawal symptoms.     

Saliva cotinine and thiocyanate: Chemical indicators of smokeless tobacco and cigarette use in adolecents

Recent attempts to measure smoking behavior using chemical tests may have been confounded by the use of smokeless tobacco. An objective measure of smokeless tobacco use is needed, particularly among adolescents who may not provide accurate self-reports of tobacco usage. Saliva cotinine was used to distinguish self-reported tobacco users from nonusers and a combination of saliva cotinine and thiocyanate (SCN) tests was used to distinguish smokers from smokeless tobacco users. The subjects were 471 students in grades 7 through 11 who lived in a high-tobacco production area. Approximately 89% of reported nonusers had no detectable cotinine and 99% of nonusers had levels <25 ng/ml. Of those who had used tobacco within the last 12 hr, 95% had detectable levels of cotinine. Samples that tested positive for cotinine were also tested for SCN. Eighty-six percent of smokers and 74% of mixed users had SCN values of >1000 mol/liter, while only 14% of smokeless users had SCN values at that level. The combination of cotinine and SCN was effective in distinguishing smokers from smokeless users but was not effective in distinguishing mixed use from the other two types of use.Funded by the National Cancer Institute CA 44004-01.     

Hepatitis C virus infection among noninjecting drug users in New York City

The prevalence of hepatitis C virus (HCV) infection among noninjecting drug users has been reported to be higher than in the general population, but the reasons for this observation remain unclear. Noninjecting drug users aged 15-40 years and who used drugs for no longer than 10 years were enrolled in the study. The participants were interviewed about risk behaviors and had specimens drawn for serological testing. Of 276 enrolled, 4.7% were infected with HCV. Drug users who had ever sniffed or snorted heroin in combination with cocaine were significantly more likely to be infected with HCV compared with those who never sniffed or snorted heroin with cocaine. No other drug use or sexual risk behaviors were found to be associated with HCV infection. These findings suggest that sniffing or snorting heroin with cocaine may explain the increase frequently found in HCV infection among noninjectors, but further studies are necessary.     

Problem drug users known to Bristol general practitioners

A 12-month prospective survey was undertaken of all 239 problem drug users known to general practitioners in Bristol and the doctors' attitudes towards them. The drug users were predominantly young, aged 15-35 years, and males outnumbered females by approximately two to one. Seventy-eight per cent had problems associated with opiates, almost invariably heroin, 10% had problems with stimulants (mainly amphetamine powder), and others had problems with hallucinogens, cannabis, barbiturates and solvents. Opiate dependence was the commonest single problem but ill health, hepatitis, psychiatric illnesses, relationship problems, work and financial difficulties were also frequently mentioned.

There was a wide variation in the numbers of problem drug users seen by individual practices, which related both to the situation of the practice and the widely varying attitudes of the partners towards drug users and drug problems. General practitioners were aware of the grapevine that transmits news of their treatment to other users, and individual practices had typically evolved a general strategy for all drug users, to minimize arguments. General practitioners were asked their views about specialist services: they thought that services in the area for drug users were inadequate to help them and their patients in 58% of cases. Several suggestions were made for additional services which were needed.