Low-dose trimethoprim-sulfamethoxazole prophylaxis for toxoplasmic encephalitis in patients with AIDS

OBJECTIVE

To determine the efficacy of low-dose trimethoprim-sulfamethoxazole (trimethoprim, 160 mg plus sulfamethoxazole, 800 mg; one tablet twice daily, 2 days per week) as primary prophylaxis against toxoplasmic encephalitis in patients with human immunodeficiency virus (HIV) infection and previous Pneumocystis carinii pneumonia.

DESIGN

A retrospective study.

SETTING

Tertiary referral teaching hospital.

PATIENTS

During a 3-year period after primary episodes of P. carinii pneumonia, 60 patients received trimethoprim-sulfamethoxazole, and 95 patients received pentamidine (aerosolized in 78 patients and intravenous in 17 patients) as secondary prophylaxis.

RESULTS

No patient in the trimethoprim-sulfamethoxazole group and no patient seronegative for Toxoplasma gondii developed toxoplasmic encephalitis, compared with 12 of 36 (33%; 95% Cl, 19% to 51%) seropositive patients in the pentamidine group (trimethoprim-sulfamethoxazole compared with pentamidine, P = 0.008). A significant difference was seen in the time to development of toxoplasmic encephalitis between the trimethoprim-sulfamethoxazole group (no case at 1153 days) and the pentamidine group (median time, 460 days) (P = 0.004). Neither the CD4+ lymphocyte count at the start of prophylaxis nor zidovudine therapy during the period of prophylaxis influenced the rate of toxoplasmic encephalitis in any group.

CONCLUSIONS

Low-dose trimethoprim-sulfamethoxazole (four tablets per week) appears to be effective prophylaxis against toxoplasmic encephalitis in HIV-infected patients with previous P. carinii pneumonia. A prospective, randomized, controlled study is needed to further evaluate these findings.

Human T-lymphotropic virus type I-associated myelopathy in patients with the acquired immunodeficiency syndrome

We describe two cases of serologically confirmed human T-lymphotropic virus type I (HTLV-I)-associated myelopathy involving North American men coinfected by the human immunodeficiency virus type 1. Our first patient suffered from a gradually progressive spastic paraparesis for 10 years prior to presenting with Kaposi's sarcoma, while our second patient developed subacutely progressive spastic paraparesis in the setting of full-blown acquired immunodeficiency syndrome. Autopsy examination of the spinal cords from these two cases revealed widespread axonal loss and demyelination principally involving the lateral columns of case no. 1 and the lateral and anterior columns of case no. 2. Vascular sclerosis and hyalinization were prominent in both cases, but in neither was there a conspicuous inflammatory component. In case no. 2, HTLV-I mRNA was not detected by in situ hybridization, but HTLV-I proviral DNA sequences were detected in this case by polymerase chain reaction. Neither case exhibited multinucleated cell (human immunodeficiency virus type 1) myelitis, vacuolar myelopathy, or evidence of HTLV-II infection by polymerase chain reaction assay.

Cerebrospinal fluid beta 2-microglobulin in patients with AIDS dementia complex: an expanded series including response to zidovudine treatment

OBJECTIVE

To determine the relationship between cerebrospinal fluid (CSF) beta 2-microglobulin (beta 2M) and severity of AIDS dementia complex (ADC), and between CSF beta 2M and response of ADC to zidovudine.

DESIGN

A prospective study.

SETTING

Tertiary referral hospital.

PATIENTS, PARTICIPANTS

Seventy-eight patients with varying stages of ADC were selected from a subgroup of a cohort of HIV-seropositive patients who are being studied prospectively for the neurological complications of HIV-1 infection. To enter our study, patients had to have an ADC stage of at least 0.5 (equivocal symptoms or abnormal neurological signs in the absence of functional impairment). A control group of 11 HIV-1-seropositive, neurologically normal patients was chosen randomly from the patients followed in the Multicenter AIDS Cohort Study.

INTERVENTIONS

Patients were assessed neurologically and neuropsychologically and computed tomography of the brain and CSF studies were performed.

MAIN OUTCOME MEASURES

Patients were staged according to severity of ADC on clinical criteria. Neuropsychological test scores were converted to an impairment score. CSF beta 2M was quantified in both serum and CSF of all patients and in 10 patients with pre- and post-zidovudine assessments.

RESULTS

There was a high correlation between CSF beta 2M concentration and severity of ADC (P less than 0.0001); treatment with zidovudine significantly reduced these concentrations (P = 0.013). CSF beta 2M concentration was independent of CSF white-cell count and blood-brain barrier impairment. Other CSF changes in the same patients (including blood-brain barrier permeability to albumin, intrathecal synthesis of immunoglobulin G and HIV-1-p24-antigen levels) were less useful as objective correlates of ADC severity and response to zidovudine therapy.

CONCLUSIONS

CSF beta 2M may be a valuable marker of ADC severity and response to antiviral therapy.

Medical management of AIDS patients. Central and peripheral nervous system abnormalities

This article discusses the wide range of neurologic complications of HIV infection according to degree of advancement of systemic HIV disease. The focus is principally on those disorders that appear at least in part to be directly related to HIV: AIDS dementia complex, peripheral neuropathy, and myopathy. Unusual disturbances such as seizures and transient neurologic disorders are also discussed.

Pursuit eye movement dysfunction in HIV-1 seropositive individuals

Studies of smooth pursuit eye movements were conducted in 30 ambulatory drug-free HIV-1 seropositive patients who did not yet manifest marked clinical signs of the AIDS Dementia Complex. Seropositive patients demonstrated disturbances in pursuit eye movements that were correlated with extent of immunosuppression, with impairments on neuropsychological tests of fine motor control/speed, and with independent clinical staging of the AIDS Dementia Complex. The results provide quantitative evidence that oculomotor disturbances are present in HIV-1 seropositive individuals before the manifestation of marked AIDS Dementia Complex. For this reason, and because more severe eye movement impairments have been observed in patients with AIDS, quantitative eye movement studies may provide a useful neurobehavioral procedure for characterizing and monitoring progression of CNS involvement associated with HIV-1 infection from early in its course.

AIDS dementia complex and HIV-1 infection: a view from the clinic

The AIDS dementia complex (ADC) is a clinical syndrome which characteristically presents as a "subcortical dementia" with cognitive, motor and behavioral changes. While the pathogenesis remains puzzling in a number of critical aspects, ADC likely relates in a fundamental way to HIV-1, itself, rather than to a secondary, opportunistic condition. This review focuses on some of the clinical information which bears on the pathogenesis of this syndrome and its relation to HIV-1 infection. This information derives from studies of the clinical character of ADC, its epidemiology and natural history, cerebrospinal fluid analysis, neuroimaging results, clinical correlates of pathological findings and its response to antiviral therapy.

HTLV-I-associated myelopathy associated with blood transfusion in the United States: epidemiologic and molecular evidence linking donor and recipient

Six months after receiving 58 units of blood components, a 65-year-old white man from New York City, with no other risk factors for human T-lymphotropic virus type I (HTLV-I) infection, developed HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Investigation of blood donors identified a 25-year-old white Hispanic woman from Florida whose platelets had been given to the patient and who was seropositive for the virus on a serum specimen obtained 2 years after the donation. She was born in Cuba and had had 2 sexual relationships with men who either had been born in or had resided in the Caribbean. Polymerase chain reaction (PCR) studies of peripheral blood mononuclear cells indicated that both donor and recipient were infected with HTLV-I. Molecular studies of a 595-nucleotide sequence in the 5' envelope region of HTLV-I indicated that the viruses from donor and recipient were identical in each of 32 positions in which published HTLV-I sequences demonstrate molecular heterogeneity; the donor and recipient viruses were also identical in 2 additional positions in which they differed from all published sequences. Transfusion-associated HAM/TSP has occurred in the United States, but additional cases should be prevented by screening blood donations for HTLV-I. Molecular studies of HTLV-I may prove useful in defining the genetic heterogeneity of HTLV-I isolates in the United States and in studying transmission of this virus.

Quinolinic acid in cerebrospinal fluid and serum in HIV-1 infection: relationship to clinical and neurological status

Quinolinic acid is an "excitotoxic" metabolite and an agonist of N-methyl-D-aspartate receptors. Of patients infected with human immunodeficiency virus type 1 (HIV-1) who were neurologically normal or exhibited only equivocal and subclinical signs of the acquired immunodeficiency syndrome (AIDS) dementia complex, concentrations of quinolinic acid in cerebrospinal fluid (CSF) were increased twofold in patients in the early stages of disease (Walter Reed stages 1 and 2) and averaged 3.8 times above normal in later-stage patients (Walter Reed stages 4 through 6). However, in patients with either clinically overt AIDS dementia complex, aseptic meningitis, opportunistic infections, or neoplasms, CSF levels were elevated over 20-fold and generally paralleled the severity of cognitive and motor dysfunction. CSF concentrations of quinolinic acid were significantly correlated to the severity of the neuropsychological deficits. After treatment of AIDS dementia complex with zidovudine and treatment of the opportunistic infections with specific antimicrobial therapies, CSF levels of quinolinic acid decreased in parallel with clinical neurological improvement. By analysis of the relationship between levels of quinolinic acid in the CSF and serum and integrity of the blood-brain barrier, as measured by the CSF:serum albumin ratio, it appears that CSF levels of quinolinic acid may be derived predominantly from intracerebral sources and perhaps from the serum. While quinolinic acid may be another "marker" of host- and virus-mediated events in the brain, the established excitotoxic effects of quinolinic acid and the magnitude of the increases in CSF levels of the acid raise the possibility that quinolinic acid plays a direct role in the pathogenesis of brain dysfunction associated with HIV-1 infection.

Cerebrospinal fluid neopterin in human immunodeficiency virus type 1 infection

We evaluated cerebrospinal fluid (CSF) concentrations of neopterin, a putative marker of activated macrophages, in 97 subjects infected with human immunodeficiency virus type 1 who had a spectrum of neurological complications. The highest CSF neopterin concentrations occurred in those with neurological opportunistic infections, primary central nervous systems lymphoma, and acquired immunodeficiency syndrome (AIDS) dementia complex. In general, the CSF concentration of neopterin was independent of CSF cell count and blood-brain barrier disruption to albumin. In the patients with AIDS dementia complex, CSF neopterin concentrations correlated with severity of disease and decreased in conjunction with clinical improvement following treatment with zidovudine. These results suggest that CSF neopterin, although not disease-specific, may be useful as a surrogate marker for the presence of AIDS dementia complex and its response to antiviral therapy.

Interferon-alpha with zidovudine: safety, tolerance, and clinical and virologic effects in patients with Kaposi sarcoma associated with the acquired immunodeficiency syndrome (AIDS)

OBJECTIVE

To evaluate safety, tolerance, and potential efficacy of interferon-alpha and zidovudine combination therapy in patients with Kaposi sarcoma and the acquired immunodeficiency syndrome (AIDS).

DESIGN

Open, phase-I study with randomization between two preparations of interferon-alpha.

SETTING

Outpatient clinic of a cancer research center.

PATIENTS

Forty-three patients with Kaposi sarcoma associated with AIDS.

INTERVENTIONS

Patients were treated with interferon-alpha, 4.5, 9, or 18 million U/d, and zidovudine, 100 or 200 mg orally every 4 hours.

MEASUREMENTS AND MAIN RESULTS

Neutropenia was the major dose-limiting toxicity. Fatigue, liver enzyme elevation, anemia, and thrombocytopenia were dose-limiting in some patients. Maximum tolerated dosages for interferon-alpha 2a with zidovudine, respectively, were 4.5 million U/d with 200 mg every 4 hours or 18 million U/d with 100 mg every 4 hours. An interferon-alpha n1 [corrected] dosage of 9 million U/d with zidovudine dosages of either 100 or 200 mg every 4 hours induced dose-limiting toxicity in most patients. Of 37 evaluable patients, 17 (46%; 95% CI, 30% to 62%) showed complete or partial tumor regression. Antitumor effects occurred more frequently in patients with baseline CD4 counts above 200 x 10(6) cells/L (65%) than in patients with lower baseline counts (30%, P = 0.05). Effects on CD4 cells were related to both initial CD4 count and interferon dose. Increased skin test reactivity and decreased serum human immunodeficiency virus (HIV) p24 antigen and virus recovery from blood cells were seen.

CONCLUSIONS

Combined therapy with interferon-alpha and zidovudine can be safely administered to patients with AIDS and Kaposi sarcoma. The observed effects on tumor growth, HIV replication, and immune function support further studies of the combination in patients at various stages of HIV infection.

The neurological features of early and 'latent' human immunodeficiency virus infection

Neurological manifestations of unknown cause occurring in patients who become or are HIV antibody positive with presumed normal immune function have been described recently. This report adds a further six cases, all of whom had normal CD4+ cell counts either throughout the period of observation or after the episode of seroconversion. Three had an acute presentation, two in the context of documented seroconversion consisting of one of the following: an encephalitis, an ataxia, and confusion with neuralgic amyotrophy. Three had a subacute disorder occurring at a later phase of HIV infection but before opportunistic infections or neoplasms, and marked by a static mild cognitive deficit. This report extends the range of abnormalities that may be seen at seroconversion and documents the presence of a non-progressive cognitive deficit occurring in the latent phase of HIV infection.

AIDS-related vacuolar myelopathy is not associated with coinfection by human T-lymphotropic virus type I

Assessment of antibodies against human T-lymphotropic virus type I (HTLV-I) by enzyme-linked immunoassay, immunofluorescence, and Western blot was undertaken in patients with pathologically or clinically diagnosed acquired immunodeficiency syndrome-related vacuolar myelopathy to determine whether this retrovirus could be etiologically implicated in this disorder. No serological evidence for HTLV-I was found in the patients with vacuolar myelopathy, though 1 patient with an atypical myelopathy did have antibodies against HTLV-I.

Dissociation of AIDS-related vacuolar myelopathy and productive HIV-1 infection of the spinal cord

Although merging clinically within the spectrum of the AIDS dementia complex, vacuolar myelopathy is a pathologically distinct entity detected in up to 30% of autopsied patients succumbing to the late complications of human immunodeficiency virus type 1 (HIV-1) infection. Using immunohistochemistry and in situ hybridization to detect an HIV-1 core protein and viral mRNA, respectively, in tissue sections, and culture isolation to assess infectious virus in tissue homogenates, we found that vacuolar myelopathy was independent of productive HIV-1 infection of the spinal cord and brain. These results indicate that AIDS-associated vacuolar myelopathy is either not related directly to spinal cord HIV-1 infection or involves nonproductive infection and pathobiological processes distinct from those responsible for the multinucleated-cell inflammatory infiltrates that serve as histopathologic markers of productive CNS HIV-1 infection.

Cerebrospinal fluid beta 2 microglobulin in patients infected with human immunodeficiency virus

We prospectively evaluated CSF concentrations of beta 2 microglobulin (beta 2M) in 65 human immunodeficiency virus type 1 seropositive patients. The highest concentrations occurred in those with lymphoma, neurologic opportunistic infections, and acquired immune deficiency syndrome dementia complex (ADC). There was a high correlation between the CSF beta 2M concentration and ADC severity, suggesting that CSF beta 2M may be useful as a marker for the development, progression, and perhaps response to treatment of ADC. Elevated CSF beta 2M was not due to CSF pleocytosis and was usually independent of blood-brain barrier dysfunction.

Diagnosis of Wernicke's encephalopathy

Records of the emergency medical admissions to a large teaching hospital over a one year period were examined for evidence of Wernicke's encephalopathy or Korsakoff's syndrome. It was found that only 0.4% of the population studied had the classical triad of Wernicke's encephalopathy, namely confusion, ophthalmoplegia, and ataxia. If two of these three criteria are allowed in the absence of other causes then 2.2% of the population had this limited Wernicke's encephalopathy or Korsakoff's syndrome. It is concluded that the diagnosis of Wernicke's encephalopathy should not rely on the presence of all three criteria; any two of the three in the absence of other causes will suffice for the diagnosis.