Diagnosis of toxoplasmic encephalitis in HIV-infected patients.
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Biomedical subjects
Publications and source records attributed to A Castagna.
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OBJECTIVE: To assess the diagnostic reliability of polymerase chain reaction (PCR) on cerebrospinal fluid (CSF) for virus-associated opportunistic diseases of the central nervous system (CNS) in HIV-infected patients. DESIGN: CSF samples from 500 patients with HIV infection and CNS symptoms were examined by PCR. In 219 patients the PCR results were compared with CNS histological findings. METHODS: Nested PCR for detection of herpes simplex virus (HSV) type 1 or 2, varicella zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus 6 (HHV-6), and JC virus (JCV) DNA. Histopathological examination of CNS tissue obtained at autopsy or on brain biopsy. RESULTS: DNA of one or more viruses was found in CSF in 181 out of 500 patients (36%; HSV-1 2%, HSV-2 1%, VZV 3%, CMV 16%, EBV 12%, HHV-6 2%, and JCV 9%). Among the 219 patients with histological CNS examination, HSV-1 or 2 was detected in CSF in all six patients (100%) with HSV infection of the CNS, CMV in 37 out of 45 (82%) with CMV infection of the CNS, EBV in 35 out of 36 (97%) with primary CNS lymphoma, JCV in 28 out of 39 (72%) with progressive multifocal leukoencephalopathy. Furthermore, HSV-1 was found in one, VZV in four, CMV in three, EBV in three, HHV-6 in seven, and JCV in one patient without histological evidence of the corresponding CNS disease. CONCLUSIONS: CSF PCR has great relevance for diagnosis of virus-related opportunistic CNS diseases in HIV-infected patients as demonstrated by its high sensitivity, specificity, and the frequency of positive findings.
Plants of two wheat cultivars (Triticum aestivum L., cultivars Mec and Chiarano), differing in sensitivity towards sulfur dioxide, were fumigated with 96 nL L-1 of SO2 for four months. Thylakoid membranes were subjected to two-dimensional electrophoresis in order to detect possible changes in the protein patterns. We found the greatest alterations following treatment in the polypeptide profiles of the most sensitive cultivar, Mec, even if some significant changes were also detected in the plants of the cultivar Chiarano.
Seven AIDS patients with central nervous system (CNS) disease and cytomegalovirus (CMV) DNA in cerebrospinal fluid (CSF) were evaluated before and 3 weeks after standard ganciclovir treatment by nested polymerase chain reaction (PCR) on limiting dilutions and by quantitative PCR. After therapy, PCR CSF was negative for CMV in 3 patients with low baseline levels of CMV DNA and positive with decreased DNA titers in 4 patients with higher baseline levels. CMV pp65 antigen in polymorphonuclear leukocytes was found in 6 of 7 patients before therapy and in none of 5 after therapy. At autopsy, CMV was found in the CNS of the 4 cases examined, including 3 whose CSF was continuously positive by PCR. Quantitative PCR of CSF is useful for monitoring ganciclovir treatment in CMV infection of the CNS. In AIDS patients, standard ganciclovir treatment seems effective in reducing but not suppressing viral replication in severe cases of CMV infection of the CNS.
The methylation and transsulfuration pathways are intimately linked and have been implicated in the progression of neurologic damage and immune cell depletion caused by human immunodeficiency virus (HIV) infection. We studied the following metabolites related to these pathways: S-adenosylmethionine (SAMe), homocysteine, cysteine, cysteinyl-glycine, and glutathione (GSH) in blood and CSF of 16 HIV-infected patients with neurologic complications and 20 HIV-negative control patients undergoing lumbar punctures for other medical reasons. We confirmed recent studies of decreased CSF SAMe concentrations in HIV infection and demonstrated that diastereomers of SAMe are present in CSF but not in plasma or erythrocytes from both HIV-infected and HIV-negative patients. In HIV-infected patients, CSF GSH and cysteinyl-glycine, but not homocysteine or cysteine, were significantly reduced. This is the first report of decreased CSF GSH induced by HIV infection. GSH has a regulatory effect on the synthesis of SAMe in hepatic tissue, and the same mechanism may also apply in the CNS. Administration of SAMe-butanedisulphonate, 800 mg/d intravenously for 14 days, was associated with significant increases in CSF SAMe and GSH. These findings have potentially important therapeutic implications for the use of SAMe in protecting against SAMe and GSH deficiency in the CNS of HIV-infected patients.
Alterations of sleep structure have been reported in asymptomatic human immunodeficiency virus (HIV)-infected subjects. In these patients some authors have found an increased percentage of slow wave sleep (SWS) and a SWS preponderance in the second half of the night, as well as subjective sleep complaints. Other authors have found an increased stage 1 non-rapid eye movement (NREM) and reduced stage 2 NREM percentages in asymptomatic subjects. We evaluated the macrostructure and the microstructure (cyclic alternating pattern, CAP) of sleep in nine HIV-infected asymptomatic men without sleep complaints or psychiatric illness, in comparison with nine age-matched controls. Our study showed a decreased amount of SWS and a significantly higher CAP rate in HIV-subjects, suggesting an altered organization of the sleep process in these patients.
To evaluate the diagnostic relevance and the clinical impact of the cerebrospinal fluid (CSF) polymerase chain reaction (PCR) for cytomegalovirus (CMV) DNA in the diagnosis of CMV infection of the central nervous system (CNS), 220 acquired immune deficiency syndrome (AIDS) patients with neurological disease were examined. CSF was drawn 1-180 days before death, concomitantly with clinical neurological disease, and autopsy was performed in all the cases. CMV DNA was detected in the CSF from 36 of 45 patients (82%) with CMV infection of the CNS, and in 2 of 175 without CMV infection of the CNS at autopsy. The sensitivity of the method was 82%, the specificity 99%, the positive predictive value 95%, and the negative predictive value 96%. An extensive CMV ventriculitis or encephalitis was shown by histopathology in the majority of the CSF PCR-positive patients with overt clinical encephalitis. Minor CMV lesions only, not likely to cause relevant clinical symptoms, were observed in some CSF PCR-positive patients, concomitant with other opportunistic CNS diseases. CSF PCR is a reliable means for diagnosis of CMV infection of the CNS in patients with AIDS. A positive PCR result, however, requires careful interpretation in the individual clinical context.
In this study we evaluated the release of leukotriene B4 (LTB4) in the cerebrospinal fluid (CSF) of 12 patients with Acquired Immunodeficiency Syndrome (AIDS), which disease was complicated by Cryptococcal Meninigitis and in CSF of 12 control subjects with inflammatory and degenerative pathologies of the Central Nervous System (CNS). We obtained low levels of LTB4 in all the AIDS patients (mean 60.5 pg/ml), while the HIV negative subjects with degenerative and inflammatory pathologies of CNS showed a mean of 91.5 pg/ml. The finding of low levels of this inflammatory reaction mediator agrees with the limited clinical symptoms of cryptococcal meningoencephalitis in patients affected by AIDS.
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The effect of intravenous lidocaine (4 mg kg-1) on ganglionic and spinal neuronal hyperactivity following sciatic chronic constriction injury (CCI) was studied in anaesthetized and curarized rats. A significant difference in the time course and magnitude of the lidocaine effect on the two neuronal populations was found. Longer lasting and more potent inhibitory effects on the dorsal horn neurones in comparison with ganglionic neurones were observed. By contrast the magnitude and time course of the inhibitory effects were highly comparable in dorsal horn neurones before and after acute rhizotomy. The results indicate that peripheral and central effects of lidocaine are not sequentially related. The likelihood that lidocaine inhibition at central sites may have a role in its analgesic effect, at least in the neuropathic model, is discussed.
OBJECTIVE: To study the accuracy of polymerase chain reaction (PCR) for Toxoplasma gondii DNA in the cerebrospinal fluid (CSF) of AIDS patients for the diagnosis of T. gondii encephalitis. PATIENTS: Eighty-two AIDS patients with brain lesions. At autopsy, 19 patients (group A) had toxoplasmic encephalitis and 33 (group B) primary brain lymphoma or other infections. Brain histology was not available for 30 patients; cerebral lesions improved after anti-Toxoplasma therapy in 16 (group C), but there was no improvement in 14 patients (group D). METHODS: T. gondii RH strain was serially diluted in microplate wells. After heat denaturation, nested PCR was performed on diluted tachyzoites and on 10 microliters CSF with primers flanking the B1 repetitive region of T. gondii genome. RESULTS: DNA from one to five tachyzoites was detected in each experiment. PCR was positive in eight (42.1%) out of 19 group A samples, none of the group B samples, 10 (62.5%) out of 16 group C samples and none of the group D samples. Among group A and C patients, PCR was positive in all 11, and in seven out of 24 (29.1%; P < 0.04) patients who had received anti-Toxoplasma therapy for less or more than 1 week at the time of rachicentesis, respectively. CONCLUSIONS: Nested PCR for T. gondii in CSF may improve early differential diagnosis of AIDS-associated focal brain lesions. Higher diagnostic accuracy was achieved when lumbar puncture was performed in the first week of anti-Toxoplasma therapy.
Epstein-Barr virus (EBV) is constantly associated with AIDS-related primary lymphomas of the central nervous system (CNS). To assess whether EBV DNA in cerebrospinal fluid (CSF) could be used as a tumour marker, CSF samples that had been taken within 180 days before death from 85 patients with HIV infection and neurological disorders at necropsy were examined retrospectively by nested polymerase chain reaction (PCR) for EBV. Histologically evident primary CNS lymphomas were found in 17 patients, and EBV was shown in tissue by in-situ hybridisation in 16 of the 16 cases examined. All 17 patients with primary CNS lymphoma had EBV DNA in CSF. EBV DNA was found in CSF from 1 of 68 HIV-infected patients without histologically detectable lymphoma at necropsy. PCR for EBV DNA in CSF was 100% sensitive and 98.5% specific for AIDS-associated primary CNS lymphoma, and may be useful as a diagnostic tumour marker.
We measured the production of interferon-gamma (IFN-gamma) from single T cells and the T cell proliferative response to different cytomegalovirus (CMV) antigens in healthy blood donors and bone marrow transplant recipients. The antigens consisted of a CMV nuclear antigen (CMV na) containing the pp65-kDa matrix protein and the immediate early antigens but lacking CMV glycoproteins, and an antigen comprising native CMV glycoproteins (CMV gp). We also measured the IgG antibodies to CMV na and CMV gp. The T cells reacted to CMV na in CMV seropositive blood donors both with the production of IFN-gamma and with proliferation, while bone marrow transplant recipients had a deficient T cell response. After stimulation with CMV gp, no T cell response could be observed in CMV seropositive subjects. IgG antibodies to CMV na coexisted in plasma with similar levels of antibodies to CMV gp.
We evaluated the effect of zidovudine on HIV-induced lesions of the brain by comparing the neuropathological findings in 82 treated and 120 untreated patients who died from AIDS. We observed a statistically significant reduction of the number of cases with multinucleated giant cells (MGCs) in the brain and MGC-associated neuropathological damage in patients treated with zidovudine. The effects of zidovudine were time and dose related in the first 12 months of treatment, while longer periods of therapy produced no further results. The antiretroviral treatment particularly affected the frequency of diffuse demyelinating lesions of the cerebral white matter. In the patients who died with HIV-induced brain lesions but no other opportunistic brain diseases, the percentage of cases with clinical history of severe dementia was significantly lower in the group treated with zidovudine.
In this study we evaluated the release of some mediators of inflammatory reactions such as histamine (H), leukotriene B4 (LTB4), leukotriene C4 (LTC4) and prostaglandin D2 (PGD2) in the cerebrospinal fluid (CSF) of 15 patients with acquired immunodeficiency syndrome (AIDS), eight with opportunistic infections of the central nervous system (CNS) and seven without HIV-related neurological pathology, and of 25 HIV-negative control subjects with other neurological diseases. The cerebrospinal LTB4 level was increased in all the AIDS patients (mean 348 pg/ml); the control group revealed normal levels of LTB4 in the CSF (mean 63.2 pg/ml). The PGD2 level in the HIV-positive (mean 264 pg/ml) patients was higher than of the control subjects (mean 50 pg/ml), while low LTC4 levels were found both in the HIV-positive and control groups. We did not find any significant concentration of H in the CSF of either the HIV-positive or the control subjects. These findings may be due to the presence of chronic HIV infection or to the opportunistic infections of the CNS that so often occur in the latest stages of the disease.
A nested polymerase chain reaction (PCR) was evaluated for the detection of cytomegalovirus (CMV) DNA in cerebrospinal fluid (CSF). CSF and serum samples from 19 AIDS patients with intracerebral CMV infection diagnosed at autopsy were retrospectively examined. As controls, CSF and serum samples from 15 AIDS patients with only extracerebral CMV involvement at autopsy, from 10 AIDS patients without CMV infection at autopsy, and from 10 anti-human immunodeficiency virus-negative patients without ongoing CMV infection, were studied. CMV DNA was detected from patients with intracerebral CMV infection in 9 of 9, 5 of 6, and 1 of 4 CSF samples collected, respectively, 1-30, 30-90, and 90-300 days before death. Twelve of 13 sera from these patients were CMV PCR-positive. None of the control patients had CMV DNA in CSF. PCR was positive in 6 of 8 sera from AIDS patients with only extracerebral CMV infection and in serum from 1 AIDS patient without CMV involvement at autopsy. CMV PCR on CSF is highly sensitive and specific. It should be considered a rapid and reliable diagnostic method for CMV infection of the central nervous system.