Lawrence R. Crane

Racial and gender disparities in receipt of highly active antiretroviral therapy persist in a multistate sample of HIV patients in 2001

Background: National data from the mid-1990s demonstrated that many eligible patients did not receive highly active antiretroviral therapy (HAART) and that racial and gender disparities existed in HAART receipt. We examined whether demographic disparities in the use of HAART persist in 2001 and if outpatient care is associated with HAART utilization. Methods: Demographic, clinical, and pharmacy utilization data were collected from 10 US HIV primary care sites in the HIV Research Network (HIVRN). Using multivariate logistic regression, we examined demographic and clinical differences associated with receipt of HAART and the association of outpatient utilization with HAART. Results: In our cohort in 2001, 84% of patients received HAART and 66% had 4 or more outpatient visits during calendar year (CY) 2001. Of those with 2 or more CD4 counts below 350 cells/mm3 in 2001, 91% received HAART; 82% of those with 1 CD4 test result below 350 cells/mm3 received HAART; and 77% of those with no CD4 counts below 350 cells/mm3 received HAART. Adjusting for care site in multivariate analyses, age >40 years (adjusted odds ratio [AOR] = 1.13), male gender (AOR = 1.23), Medicaid coverage (AOR = 1.16), Medicare coverage (AOR = 1.73), having 1 or more CD4 counts less than 350 cells/mm3 (AOR = 1.33), and having 4 or more outpatient visits in a year (OR = 1.34) were significantly associated with an increased likelihood of HAART. African Americans (odds ratio [OR] = 0.84) and those with an injection drug use risk factor (OR = 0.86) were less likely to receive HAART. Conclusions: Although the overall prevalence of HAART has increased since the mid-1990s, demographic disparities in HAART receipt persist. Our results support attempts to increase access to care and frequency of outpatient visits for underutilizing groups as well as increased efforts to reduce persistent disparities in women, African Americans, and injection drug users (IDUs).

Pneumocystis carinii Mutations Are Associated with Duration of Sulfa or Sulfone Prophylaxis Exposure in AIDS Patients

This study was conducted to determine whether Pneumocystis carinii dyhydropteroate synthase (DHPS) gene mutations in AIDS patients with P. carinii pneumonia (PCP) are affected by duration of sulfa or sulfone prophylaxis and influence response to sulfa or sulfone therapy. The P. carinii DHPS genes from 97 AIDS patients with PCP between 1991 and 1999 from 4 medical centers were amplified, using polymerase chain reaction (PCR), and sequenced. Mutations were observed in 76% of isolates from patients exposed to sulfa or sulfone prophylaxis compared with 23% of isolates from patients not exposed (P=.001). Duration of prophylaxis increased the risk of mutations (relative risk [RR] for each exposure month, 1.06; P=.02). Twenty-eight percent of patients with mutations failed sulfa or sulfone treatment; mutations increased the risk of sulfa or sulfone treatment failure (RR, 2.1; P=0.01). Thus, an increased duration of sulfa or sulfone prophylaxis increases the chance of developing a P. carinii mutation. The majority of patients with mutations respond to sulfa or sulfone therapy.

Zidovudine alone or in combination with didanosine or zalcitabine in HIV-infected patients with the acquired immunodeficiency syndrome or fewer than 200 CD4 cells per cubic millimeter

BACKGROUND We compared two combinations of nucleosides with zidovudine alone in patients with advanced human immunodeficiency virus (HIV) infection. METHODS A total of 1102 patients with the acquired immunodeficiency syndrome or fewer than 200 CD4 cells per cubic millimeter were randomly assigned to receive zidovudine alone or zidovudine combined with either didanosine or zalcitabine. Disease progression, survival, toxic effects, and the CD4 cell response were assessed. RESULTS After a median follow-up of 35 months, disease progression or death occurred in 62 percent of the 363 patients assigned to zidovudine plus didanosine, 63 percent of the 367 assigned to zidovudine plus zalcitabine, and 66 percent of the 372 assigned to zidovudine only (P=0.24). As compared with zidovudine therapy, treatment with zidovudine plus didanosine was associated with a relative risk of disease progression or death of 0.86 (95 percent confidence interval, 0.71 to 1.03), and treatment with zidovudine plus zalcitabine was associated with a relative risk of 0.92 (95 percent confidence interval, 0.76 to 1.10). Survival was similar in the three groups. In a subgroup analysis, combination therapy delayed disease progression or death in patients who had previously received zidovudine for 12 months or less. Therapy with zidovudine plus didanosine resulted in more gastrointestinal adverse effects, and treatment with zidovudine plus zalcitabine, more neuropathy. The mean increases in CD4 cell counts at two months were higher with combination therapy than with zidovudine alone. CONCLUSIONS In patients with advanced HIV infection, combination therapy with zidovudine and either didanosine or zalcitabine is not superior to zidovudine therapy alone. However, these combinations may be more effective than zidovudine monotherapy in patients with little or no previous zidovudine treatment.

Discontinuation of Prophylaxis against Mycobacterium avium Complex Disease in HIV-Infected Patients Who Have a Response to Antiretroviral Therapy

BACKGROUND Several agents are effective in preventing Mycobacterium avium complex disease in patients with advanced human immunodeficiency virus (HIV) infection. However, there is uncertainty about whether prophylaxis should be continued in patients whose CD4+ cell counts have increased substantially with antiviral therapy. METHODS We conducted a multicenter, double-blind, randomized trial of treatment with azithromycin (1200 mg weekly) as compared with placebo in HIV-infected patients whose CD4+ cell counts had increased from less than 50 to more than 100 per cubic millimeter in response to antiretroviral therapy. The primary end point was M. avium complex disease or bacterial pneumonia. RESULTS A total of 520 patients entered the study; the median CD4+ cell count at entry was 230 per cubic millimeter. In 48 percent of the patients, the HIV RNA value was below the level of quantification. The median prior nadir CD4+ cell count was 23 per cubic millimeter, and 65 percent of the patients had had an acquired immunodeficiency syndrome-defining illness. During follow-up over a median period of 12 months, there were no episodes of confirmed M. avium complex disease in either group (95 percent confidence interval for the rate of disease in each group, 0 to 1.5 episodes per 100 person-years). Three patients in the azithromycin group (1.2 percent) and five in the placebo group (1.9 percent) had bacterial pneumonia (relative risk in the azithromycin group, 0.60; 95 percent confidence interval, 0.14 to 2.50; P=0.48). Neither the rate of progression of HIV disease nor the mortality rate differed significantly between the two groups. Adverse effects led to discontinuation of the study drug in 19 patients assigned to receive azithromycin (7.4 percent) and in 3 assigned to receive placebo (1.1 percent; relative risk, 6.6; P=0.002). CONCLUSIONS Azithromycin prophylaxis can safely be withheld in HIV-infected patients whose CD4+ cell counts have increased to more than 100 cells per cubic millimeter in response to antiretroviral therapy.

Frequencies of opportunistic diseases prior to death among HIV-infected persons

ObjectivesTo describe the complete history of major opportunistic events experienced by 1883 HIV-infected persons prior to and specifically within 6 months of death, and to determine whether the frequency of specific events varies according to demographic characteristics, risk behaviors or geographic location. DesignDescriptive case series. MethodsOf 6682 HIV-infected individuals enrolled in studies sponsored by the Community Programs for Clinical Research on AIDS between September 1990 and June 1994, 1883 died during follow-up. A complete history of AIDS-defining events was determined for these patients by combining medical history data obtained at the time of enrollment, new events that occurred during follow-up, and causes of death. ResultsThe most common opportunistic AIDS-defining events these 1883 patients experienced before death were Pneumocystis carinii pneumonia (PCP; 45%), Mycobacterium avium complex (MAC; 25%), wasting syndrome (25%), bacterial pneumonia (24%), cytomegalovirus (CMV) disease (23%) and candidiasis (esophageal or pulmonary; 22%). In addition, 47% of patients experienced two or three AIDS-defining events before death, and 22% experienced four or more events. In the 6 months prior to death, 22% of patients had PCP, 21% had MAC, and 20% had CMV disease. Significant sex and ethnic differences were found: bacterial pneumonia occurred more often before death in women compared with men; fewer blacks and Latinos than whites experienced Kaposis sarcoma (KS); and fewer blacks than whites had CMV disease before death. The percentage of patients with KS and CMV also varied by risk behavior. The frequency of 10 opportunistic diseases varied by geographic region after adjustment for demographic characteristics and risk behavior. Of note, many more patients in northeastern USA had tuberculosis and fewer had MAC. ConclusionA large percentage of individuals with HIV infection experienced multiple AIDS-defining opportunistic diseases before death. PCP, MAC, wasting syndrome, bacterial pneumonia, CMV disease, and candidiasis (esophageal or pulmonary) account for a substantial proportion of morbidity associated with HIV infection. More diseases varied by geographic location than by demographic characteristics or risk behavior of patients. Continued research on the etiology and prevention of these diseases and how they relate to one another should be a high priority.

Management of elevated intracranial pressure in patients with cryptococcal meningitis

BACKGROUND The most important predictor of early mortality in patients with HIV-associated cryptococcal meningitis is mental status at presentation; patients who present with altered mental status have up to 25% mortality. Historically, cerebrospinal fluid (CSF) diversion in HIV-negative patients with cryptococcal meningitis and signs of elevated intracranial pressure (ICP) has improved survival. In an effort to affect survival and morbidity rates in patients with HIV-associated cryptococcal meningitis, we have initiated aggressive management of elevated ICP in patients with focal neurologic deficits, mental obtundation, or both. METHODS We identified 10 patients with HIV-associated cryptococcal meningitis who presented with symptoms consistent with elevated ICP, including headache, mental obtundation, papilledema, and cranial nerve palsies. Elevated opening pressure was defined as > 20 cm CSF during lumbar puncture. In patients with elevated opening pressures who had focal neurologic deficits or mental status changes refractory to serial lumbar puncture, management consisted of immediate placement of lumbar drains for continuous drainage of CSF to maintain normal ICP (10 cm CSF). Patients with persistent elevations of spinal neuraxis pressure following lumbar drainage underwent placement of lumbar peritoneal shunts. RESULTS All patients returned to their baseline level of consciousness following normalization of ICP. Two patients were weaned from lumbar drainage. Eight patients eventually required placement of lumbar peritoneal shunts for persistently elevated ICP despite successful antifungal therapy. Follow-up ranged from 1 to 15 months. One shunt infection occurred, one lumbar peritoneal shunt was converted to a ventriculoperitoneal shunt, and one shunt was removed. CONCLUSIONS Elevated ICP in patients with HIV-associated cryptococcal meningitis is a significant source of morbidity and mortality. The use of lumbar drainage and selective placement of lumbar peritoneal shunts in the management of elevated ICP in patients with HIV-associated cryptococcal meningitis can ameliorate the sequelae of elevated ICP.

Pneumocystis carinii cytochrome b mutations are associated with atovaquone exposure in patients with AIDS

This retrospective cohort study was conducted to determine whether Pneumocystis carinii cytochrome b gene mutations in patients with AIDS and P. carinii pneumonia (PCP) are associated with atovaquone exposure. Portions of the P. carinii cytochrome b genes that were obtained from 60 patients with AIDS and PCP from 6 medical centers between 1995 and 1999 were amplified and sequenced by using polymerase chain reaction. Fifteen patients with previous atovaquone prophylaxis or treatment exposure were matched with 45 patients with no atovaquone exposure. Cytochrome b coenzyme Q binding site mutations were observed in 33% of isolates from patients exposed to atovaquone, compared with 6% from those who were not (P=.018). There was no difference in survival 1 month after treatment between patients with or without cytochrome b mutations (P=.14). Thus, cytochrome b mutations are significantly more common in patients with AIDS and PCP with atovaquone exposure, but the clinical significance of these mutations remains unknown.

Avascular Necrosis of Bone in Patients with Human Immunodeficiency Virus Infection: Report of 6 Cases and Review of the Literature

In 1998 and 1999, we diagnosed avascular necrosis of bone in 6 patients in our human immunodeficiency virus clinic practice, an incidence of 0.45%, which is 45 times greater than would be expected in the general population. Antiphospholipid antibodies and hyperlipidemia secondary to protease inhibitor therapy have been implicated as possible etiologies; however, these abnormalities cannot explain all cases of avascular necrosis of bone reported in patients with human immunodeficiency virus infection.

A Randomized Trial of Daily and Thrice-Weekly Trimethoprim-Sulfamethoxazole for the Prevention of Pneumocystis carinii Pneumonia in Human Immunodeficiency Virus-Infected Persons

We enrolled 2,625 human immunodeficiency virus-infected patients into a randomized trial to assess the efficacy and tolerability of daily vs. thrice-weekly trimethoprim-sulfamethoxazole (160 mg/800 mg) for prophylaxis of Pneumocystis carinii pneumonia (PCP). The rate of PCP was 3.5 and 4.1 per 100 person-years in the daily and thrice-weekly groups, respectively, with a relative risk (RR) of 0.82 (95% confidence interval [CI], 0.61-1.09; P = .16) (RR of <1.0 favors daily trimethoprim-sulfamethoxazole). The RR for PCP determined by on-treatment analysis was 0.59 (P = .03). The RR for death was 0.91 (P = .12); for bacterial pneumonia, 0.82 (P = .06); and for combined PCP and bacterial pneumonia, 0.84 (P = .04). Discontinuation due to adverse events occurred more commonly in the daily trimethoprim-sulfamethoxazole group (RR, 2.14; 95% CI, 1.73-2.66; P < .001). Overall estimates for efficacy end points favored daily trimethoprim-sulfamethoxazole, although rates of intolerance were higher among patients receiving that dose. Daily trimethoprim-sulfamethoxazole may offer advantages as a first choice for PCP prophylaxis; thrice-weekly dosing is an appropriate option for patients intolerant of the daily dose.

Decision making in fuzzy discrete event systems

The primary goal of the study presented in this paper is to develop a novel and comprehensive approach to decision making using fuzzy discrete event systems (FDES) and to apply such an approach to real-world problems. At the theoretical front, we develop a new control architecture of FDES as a way of decision making, which includes a FDES decision model, a fuzzy objective generator for generating optimal control objectives, and a control scheme using both disablement and enforcement. We develop an online approach to dealing with the optimal control problem efficiently. As an application, we apply the approach to HIV/AIDS treatment planning, a technical challenge since AIDS is one of the most complex diseases to treat. We build a FDES decision model for HIV/AIDS treatment based on experts knowledge, treatment guidelines, clinic trials, patient database statistics, and other available information. Our preliminary retrospective evaluation shows that the approach is capable of generating optimal control objectives for real patients in our AIDS clinic database and is able to apply our online approach to deciding an optimal treatment regimen for each patient. In the process, we have developed methods to resolve the following two new theoretical issues that have not been addressed in the literature: (1) the optimal control problem has state dependent performance index and hence it is not monotonic, (2) the state space of a FDES is infinite.