Natural history of opportunistic disease in an HIV-infected urban clinical cohort

OBJECTIVE

To determine the effect of contemporary clinical care on the natural history of opportunistic disease in an urban population infected with human immunodeficiency virus (HIV).

SETTING

Urban university HIV clinic.

DESIGN

Retrospective and prospective observational study.

PATIENTS

1246 HIV-infected patients with CD4+ counts of 300 cells/mm3 or less.

MEASUREMENTS

Incidence rates and Kaplan-Meier estimates of the probability of developing opportunistic disease with time, distribution of the CD4+ counts at which opportunistic disease develops, survival after the development of opportunistic disease, and the association between preventive drug therapies and the occurrence of opportunistic infection.

RESULTS

The most common opportunistic disease was Candida esophagitis, which had an incidence of 13.3 events per 100 person-years and a 3-year Kaplan-Meier probability of 0.30. Pneumocystis carinii pneumonia, Mycobacterium avium complex bacteremia, cytomegalovirus, and the acquired immunodeficiency syndrome dementia complex occurred at rates of 5 to 9 events per 100 person-years and 3-year Kaplan-Meier probabilities of 0.15 to 0.22. Toxoplasmosis, cryptococcal meningitis, herpes zoster, the wasting syndrome, and Kaposi sarcoma occurred at rates of about 2 to 4 events per 100 person-years and with 3-year Kaplan-Meier probabilities of 0.05 to 0.10. Non-Hodgkin lymphoma, M. tuberculosis infection, progressive multifocal leukoencephalopathy, and cryptosporidiosis were the least common disorders, with an incidence of about 1 to 2 events per 100 person-years and a 3-year Kaplan-Meier probability less than 0.05. Only the incidences of cryptococcal meningitis, secondary P. carinii pneumonia, and herpes zoster decreased (P < 0.05) between 1989-1992 and 1993-1995. Fluconazole use was associated with a decreased relative rate of 0.49 (P = 0.06) for cryptococcal meningitis and a decreased relative rate of 0.61 (P = 0.005) for esophageal candidiasis. Rifabutin use was associated with a decreased relative rate of 0.37 (P = 0.002) for M. avium complex bacteremia, and trimethoprim-sulfamethoxazole use was associated with decreased relative rates of 0.33 (P = 0.02) for secondary P. carinii pneumonia and 0.55 (P = 0.08) for primary P. carinii pneumonia. Candidiasis, herpes zoster, and M. tuberculosis infection first occurred at a median CD4+ count greater than 100 cells/mm3, but all other opportunistic diseases first occurred at a median CD4+ count less than 50 cells/mm3. Median survival after diagnosis varied from 35 days for non-Hodgkin's lymphoma to 680 days for herpes zoster.

CONCLUSIONS

In the patients studied, the incidences of secondary P. carinii pneumonia, cryptococcal meningitis, and herpes zoster have declined in the past 5 years. The incidences of primary P. carinii pneumonia and Kaposi sarcoma appear to be declining compared with historical estimates. However, although these and other opportunistic diseases continue to be relatively frequent complications of HIV infection, they are first occurring at more advanced immunosuppression than in the past. Continued efforts are needed to develop effective strategies for preventing opportunistic disease in very advanced HIV infection.

Risk factors for pneumococcal disease in human immunodeficiency virus-infected patients

To identify risk factors for pneumococcal infection among human immunodeficiency virus-infected patients, a nested case-control study was done in an urban university human immunodeficiency virus clinic. Subjects with pneumococcal illness seen between 1 January 1990 and 1 July 1994 (n=85) were randomly matched to controls from the same population. Patients with pneumococcal disease were more likely than controls to be African Americans (adjusted odds ratio [OR]=3.92), have <200 CD4 cells/mm3 (adjusted OR=3.38), have a history of any pneumonia (adjusted OR=3.28), and have an albumin level of <3.0 g/dL (adjusted OR=6.25). Use of zidovudine (adjusted OR=0.38) and pneumococcal vaccination when the subject had >200 CD4 cells/mm3 (adjusted OR=0.22) were less common in cases than in controls. Similar results were found when only cases with infections of usually sterile sites were analyzed. Pneumococcal vaccine may be most protective when it is administered before advanced immunodeficiency develops.

Hantavirus serologies in patients hospitalized with community-acquired pneumonia

In many patients, the etiology of community-acquired pneumonia is not known but may be caused by previously undescribed pathogens in some cases. The recently identified hantavirus Sin Nombre (SN) causes hantavirus pulmonary syndrome. Because sporadic cases have occurred outside the range of its reservoir (the deer mouse Peromyscus maniculatus), an investigation sought to determine whether hantaviruses contributed to cases of community-acquired pneumonia in a large Baltimore hospital. Acute-phase sera from 385 hospitalized patients with pneumonia were examined using an IgG ELISA technique with antigens prepared from several hantaviruses: prototype Hantaan (HTN), Seoul (SEO), Puumala (PUU), Convict Creek (HN107), and SN. Of 385 sera, 8 (2.1%) showed some reactivity with one or more HTN, SEO, or PUU antigens but none had detectable specific IgM antibodies. No sera were reactive with SN or HN107 antigens. Thus, hantaviruses are an uncommon cause of community-acquired pneumonia in the Baltimore area.

Risk factors for fluconazole-resistant candidiasis in human immunodeficiency virus-infected patients

In a case-control study to identify risk factors for fluconazole-resistant oroesophageal candidiasis in human immunodeficiency virus-infected patients, 25 patients with clinical and in vitro fluconazole-resistant candidiasis were paired with controls who had treatment-responsive candidiasis and who had been observed for similar time periods. After their first episode of candidiasis, patients who later developed fluconazole resistance had more treated episodes than did matched controls (cases, 3.1; controls, 1.8; P = .004), lower median CD4 cell counts (11/mm3 vs. 71/mm/3; P = .004), and greater median durations of all antifungal therapy (419 vs. 118 days; P < .001) and of systemic azole therapy (272 vs. 14 days; P < .001). When paired with a second set of controls matched by CD4 cell count as well as first diagnosis of candidiasis, cases continued to show greater median exposure to azoles (272 vs. 88 days; P = .005). These data indicate that advanced immunosuppression and exposure to oral azoles are risk factors for the development of fluconazole resistance.

Design of the multicenter study of hydroxyurea in sickle cell anemia. Investigators of the Multicenter Study of Hydroxyurea

The Multicenter Study of Hydroxyurea in Sickle Cell Anemia is a randomized double-blind placebo-controlled trial to test whether hydroxyurea can reduce the rate of painful crises in adult patients who have at least three painful crises per year. The sample size of 299 patients yields at least 90% power to detect a 50% or greater reduction in crisis rate. Dosage starts at 15 mg/kg/day and is titrated to the patient's maximum tolerated dose up to 35 mg/kg/day. Placebo dosage is titrated in similar fashion to maintain blinding. Attempts are made to ascertain medical contacts for at least 2 years after study entry. The Core Laboratory, Treatment Distribution Center, and Data Coordinating Center collaborate to provide standardized monitoring for toxicity and dose adjustments. The Core Laboratory also reduces the possibility of inadvertent unmasking of treatment assignment during review of hematologic data in clinical centers. An independent Crisis Review Committee classifies clinical events to assure that outcome evaluations are standardized and unbiased by knowledge of treatment assignments. The Data and Safety Monitoring Board assures scientific integrity of the study, as well as the safety and ethical treatment of study patients. We expect the study to determine whether or not treatment with hydroxyurea can offer significant clinical benefit to patients with the most common hereditary disorder among African-Americans in the United States.

Clostridium difficile colitis: an efficient clinical approach to diagnosis

OBJECTIVE

To define clinical and laboratory variables that suggest the presence of Clostridium difficile colitis and to establish the number of stool specimens needed to reasonably exclude the diagnosis of C. difficile colitis.

DESIGN

Prospective study of consecutive inpatients whose stool specimens were sent to be evaluated for the presence of C. difficile toxin.

SETTING

University teaching hospital.

PATIENTS

268 hospital inpatients in medical, surgical, and gynecology units.

MEASUREMENTS

Structured history and physical examination; detection of C. difficile toxin by cytotoxin tissue-culture assay with anti-C. difficile antiserum neutralization and by enzyme-linked immunoassay (EIA) for C. difficile toxins A and B; and detection of fecal leukocytes by microscopic examination and by latex agglutination lactoferrin assay.

RESULTS

43 of 268 consecutive inpatients were positive for C. difficile toxin by EIA or tissue-culture assay. Although toxin was detected by EIA alone in 39 of the 43 patients, it was detected in an additional 4 patients (10%) by tissue-culture assay alone. Univariate and multivariate logistic regression analysis showed that the following clinical and laboratory features were associated with C. difficile toxin positivity: the onset of diarrhea 6 or more days after the administration of antibiotics (odds ratio, 1.38 [95% CI, 1.10 to 3.79]); hospital stay longer than 15 days (odds ratio, 1.33 [CI, 1.09 to 3.95]); the presence of fecal leukocytes determined by microscopy (odds ratio, 2.39 [CI, 1.05 to 5.42]) or lactoferrin assay (odds ratio, 3.74 [CI, 1.80 to 7.76]); the presence of semiformed (as opposed to watery) stools (odds ratio, 2.33 [CI, 1.10 to 4.90]); and cephalosporin use (odds ratio, 2.36 [CI, 1.10 to 5.09]). Toxin-positive patients were no more likely than controls to have had fever, abdominal pain or cramps, leukocytosis, green-colored diarrhea, or blood in the stool or to have received clindamycin or penicillin derivatives. Of the 43 patients with C. difficile toxin, 34 (79%) had positive results for the toxin on the first stool specimen, 5 (cumulative, 91%) had positive results on the second specimen, and 4 had positive results on the third specimen. Overall, the negative predictive value of the first stool specimen was 97%. All patients who had two or more clinical or laboratory predictors were diagnosed with C. difficile disease when either the first or the second stool specimen was positive for toxin.

CONCLUSIONS

Clinicians at the bedside can use readily available clinical and laboratory information to decide which patients are likely to have C. difficile disease and when it is appropriate and useful to order specific diagnostic tests for C. difficile toxin. Such data are also useful in determining the number of stool samples that reasonably excludes the diagnosis of C. difficile colitis.

Survival analysis of two controlled trials of rifabutin prophylaxis against Mycobacterium avium complex in AIDS

OBJECTIVES

Rifabutin prophylaxis has been shown to significantly decrease the incidence of Mycobacterium avium complex (MAC) bacteremia in two randomized controlled clinical trials, but a survival benefit has not been observed. An analysis of complete follow-up of these patients through August 1992 was performed to assess subsequent survival, because although follow-up in the previous trials was limited at the time of initial analysis, the analysis did suggest that a survival benefit might be emerging.

METHODS

Data from 1146 AIDS patients with CD4+ counts < or = 200 x 10(6)/l enrolled at 73 US and Canadian sites in two clinical trials of MAC prophylaxis were analyzed using Cox proportional hazards analysis with rifabutin use modeled as a time-dependent covariate, taking into account the initial randomized double-blind phase of the trials and the subsequent open-label phase of follow-up of those patients. Survival from date of enrollment was analyzed. Other covariates adjusted for in the analysis were CD4+ lymphocytes count, Karnofsky performance score and hospitalization for opportunistic complications of AIDS.

RESULTS

Patients who received open-label rifabutin may have had a better prognosis than those who did not, based on Karnofsky score and occurrence of opportunistic disease. Adjusting for these variables and for use of rifabutin as time-dependent covariates, the relative hazard (RH) of dying while receiving rifabutin prophylaxis was 0.74 for the entire cohort [95% confidence interval (CI), 0.60-0.91; P < 0.004]. For patients with an enrollment CD4+ count < or = 50 x 10(6)/l (n = 655), the RH was 0.75 (95% CI, 0.58-0.98), and for patients with an enrollment CD4+ count of > 50 x 10(6)/l (n = 491), the RH was 0.69 (95% CI, 0.49-0.99).

CONCLUSIONS

An analysis of the combined double-blind and open-label follow-up of two clinical trials of rifabutin prophylaxis for MAC supports the suggestion of the double-blind study that rifabutin improves survival of AIDS patients.

Neutropenia and bacterial infection in acquired immunodeficiency syndrome

BACKGROUND

In human immunodeficiency virus (HIV) disease, neutropenia occurs most commonly in patients who are also severely immunosuppressed. It is not currently known whether neutropenia is an independent risk factor for the development of bacterial infection, which is a potentially serious complication of advanced HIV disease.

METHODS

We compared the incidence of bacterial infection between 118 neutropenic patients (absolute neutrophil count [ANC], < 1 x 10(9)/L) and 118 nonneutropenic patients matched for CD4+ lymphocyte count, use of injecting drugs, and follow-up time from a demographically heterogeneous urban cohort of HIV-infected patients followed up longitudinally at the Johns Hopkins Hospital. The incidence of serious infection was analyzed separately for patients with an ANC of less than 1, less than 0.75, or less than 0.5 x 10(9)/L.

RESULTS

There were no statistically significant associations found between neutropenia and several individual bacterial infections, including bacteremia, pneumonia, endocarditis, bacterial enterocolitis, and infection of normally sterile sites for any level of neutropenia. However, for all these infections combined, the adjusted relative risk for the occurrence of bacterial infection was 2.33 (95% confidence interval, 1.00 to 5.40; P = .05) for patients with an ANC of less than 1 x 10(9)/L and 7.92 (95% confidence interval, 1.18 to 53.2; P = .03) for those with an ANC of less than 0.5 x 10(9)/L. The incidence of serious bacterial infection ranged from two to three infections per 100 person-months of neutropenia for patients with an ANC of less than 1 x 10(9)/L and three to five infections per 100 person-months of neutropenia for patients with an ANC of less than 0.5 x 10(9)/L for all bacterial infections combined.

CONCLUSIONS

Our matched cohort analysis indicates that neutropenia is an independent risk factor for bacterial infection in patients with advanced HIV disease. Given the incidence of infection, the cost-effectiveness of interventions to prevent neutropenia in advanced HIV disease should be assessed.

Community-acquired pneumonia: impact of immune status

This cross-sectional and prospective one year study evaluated adults admitted to an inner city hospital with community-acquired pneumonia. The study used extensive diagnostic methods to evaluate the etiologies of community-acquired pneumonia in hospitalized patients with differing immunologic status. Of 385 study patients, concurrent problems associated with immunosuppression were noted in 221 (57%) patients, 180 of whom were human immunodeficiency virus (HIV)-infected. The five most common causes of community-acquired pneumonia were: Streptococcus pneumoniae, Pneumocystis carinii, aspiration, Hemophilus influenzae, and gram-negative bacilli. Only 8.3% of patients had either Legionella, Chlamydia pneumoniae or Mycoplasma pneumoniae. Despite use of state-of-the-art diagnostic techniques, no diagnosis was made in 46 of 180 (25.6%) HIV-infected patients, 56 of 164 (34.1%) immunocompetent patients, and 20 of 41 (48.8%) non-HIV-infected immunosuppressed patients. The diagnostic yield of pre-antibiotic sputum culture for conventional bacteria was 99/155 (63.9%) compared to 52 of 169 patients (32.7%) with adequate post-antibiotic sputum culture (p < 0.0001). Although S. pneumonia continues to be the most commonly identified etiologic agent of community-acquired pneumonia, it is surpassed by P. carinii in the HIV-infected patient population. The apparent decline in the frequency of S. pneumoniae in our series presumably reflects administration of antibiotics prior to procurement of sputum culture. The paucity of atypical agents in this study support the current American Thoracic Society guidelines for selective use of macrolide therapy in immunocompetent adults hospitalized with community-acquired pneumonia.(ABSTRACT TRUNCATED AT 250 WORDS)

Race, sex, drug use, and progression of human immunodeficiency virus disease

BACKGROUND

The rates of progression of human immunodeficiency virus (HIV) infection and survival have been reported to differ among sociodemographic groups. It is unclear whether these differences reflect biologic differences or differences in access to medical care.

METHODS

We measured disease progression and survival in a cohort of 1372 patients seropositive for HIV who were treated at a single urban center (median follow-up, 1.6 years). We calculated the rates of survival for the entire cohort and the rates of progression to the acquired immunodeficiency syndrome (AIDS) or death among the 740 patients who presented without AIDS. We used Cox proportional-hazards analysis to examine factors associated with progression to AIDS and death.

RESULTS

Progression to AIDS or death was associated with a CD4 cell count of 201 to 350 per cubic millimeter (relative risk, 2.0; P < 0.001), the presence of symptoms at base line (relative risk, 2.0; P < 0.001), prior antiretroviral therapy (relative risk, 1.7; P = 0.003), and older age (relative risk per year of age, 1.02; P = 0.03). However, there was no relation between disease progression and sex, race, injection-drug use, income, level of education, or insurance status. In the entire cohort, a lower CD4 cell count, a diagnosis of AIDS, older age, and the receipt of antiretroviral therapy before enrollment were associated with an increased risk of death, whereas the use of prophylaxis against pneumocystis pneumonia, zidovudine use after enrollment, and having a job at base line were associated with lower risks of death. There was no significant difference in survival between men and women, blacks and whites, injection-drug users and those who did not use drugs, or patients whose median annual incomes were $5,000 or less and those whose incomes were more than $5,000.

CONCLUSIONS

Among patients with HIV infection who received medical care from a single urban center, there were no differences in disease progression or survival associated with sex, race, injection-drug use, or socioeconomic status. Differences found in other studies may reflect differences in the use of medical care.

Hepatomegaly and steatosis in HIV-infected patients receiving nucleoside analog antiretroviral therapy

BACKGROUND

A syndrome of hepatomegaly with severe steatosis has been described in case reports and case series in HIV-infected patients receiving nucleoside analog antiretroviral therapy. We wished to quantitate the incidence of this syndrome in a well characterized, demographically heterogeneous cohort of HIV-infected patients followed longitudinally.

METHODS

All patients enrolled into a comprehensive primary care HIV Clinic from July 1989 through July 1994 (N = 1836) were screened for evidence of steatosis and liver disease by assessment of hospital discharge diagnoses, pathology reports, out- and in-patient laboratory data, and clinic records.

RESULTS

A total of 322 (18%) patients had evidence of a liver abnormality. In these patients, viral hepatitis and alcohol-induced liver disease were the most common diagnoses. Only two patients had hepatomegaly with moderate to severe steatosis and acidosis. Both cases occurred in white men with very advanced HIV disease who were receiving nucleoside analog antiretroviral therapy. The incidence of the syndrome was 1.3 per 1000 person-yr of follow-up in antiretroviral users in our cohort (95% confidence interval: 0.2, 4.5 per 1000 person-yr).

CONCLUSION

The hepatic steatosis syndrome manifesting as a severe, potentially fatal complication of antiretroviral therapy in HIV disease is rare. Both men and women and patients in early and late stages of HIV infection appear to be susceptible. It is not currently known whether a milder form of this syndrome is occurring in a larger population.

Clinical spectrum of herpes zoster in adults infected with human immunodeficiency virus

To determine the incidence and clinical manifestations of herpes zoster in a hospital-based clinic for adults infected with human immunodeficiency virus (HIV), we reviewed the records of all patients for whom zoster was diagnosed at or after their first clinic visit. Fifty-two episodes of zoster occurred in 45 patients during 1,614 person-years of follow-up (incidence, 3.2 episodes per 100 person-years). The following major complications of zoster occurred in 12 patients (27%): ocular complications (5), neurological complications (4), and chronic atypical skin lesions (5). Six patients each had postherpetic neuralgia and bacterial superinfection, which were the common minor complications of zoster. Multivariate analysis revealed that only a low CD4 cell count (< or = 200/mm3) was predictive of a major complication of zoster (OR, 13.2; 95% CI, 1.52-114; P = .019). Thus, complications of herpes zoster are common in patients with HIV infection, especially those with advanced immunosuppression.

Lack of association between acyclovir use and survival in patients with advanced human immunodeficiency virus disease treated with zidovudine. Zidovudine Epidemiology Study Group

To evaluate the association between acyclovir use and survival in patients with advanced human immunodeficiency virus infection, observational data from 1044 persons with AIDS or AIDS-related complex (ARC) and < or = 250 CD4 cells/mm3 following initiation of zidovudine were analyzed. Of these patients, 336 (32%) received regular acyclovir (> or = 6 weeks in 2 months). There were no differences in mortality data between acyclovir users and nonusers overall or when analyzed from 1 year after first use of zidovudine, from time of AIDS in those with ARC at enrollment, from patients with AIDS or < 100 CD4 cells/mm3 at enrollment, or from patients taking acyclovir for up to 10 months. Acyclovir use was associated with increased mortality (relative hazard, 1.28; P = .057) independent of herpesvirus infections and of other characteristics associated with mortality. In this study, the use of acyclovir at doses for treatment of herpes simplex virus infection in combination with zidovudine was not associated with prolonged survival.

Effect of hydroxyurea on the frequency of painful crises in sickle cell anemia. Investigators of the Multicenter Study of Hydroxyurea in Sickle Cell Anemia

BACKGROUND

In a previous open-label study of hydroxyurea therapy, the synthesis of fetal hemoglobin increased in most patients with sickle cell anemia, with only mild myelotoxicity. By inhibiting sickling, increased levels of fetal hemoglobin might decrease the frequency of painful crises.

METHODS

In a double-blind, randomized clinical trial, we tested the efficacy of hydroxyurea in reducing the frequency of painful crises in adults with a history of three or more such crises per year. The trial was stopped after a mean follow-up of 21 months.

RESULTS

Among 148 men and 151 women studied at 21 clinics, the 152 patients assigned to hydroxyurea treatment had lower annual rates of crises than the 147 patients given placebo (median, 2.5 vs. 4.5 crises per year, P < 0.001). The median times to the first crisis (3.0 vs. 1.5 months, P = 0.01) and the second crisis (8.8 vs. 4.6 months, P < 0.001) were longer with hydroxyurea treatment. Fewer patients assigned to hydroxyurea had chest syndrome (25 vs. 51, P < 0.001), and fewer underwent transfusions (48 vs. 73, P = 0.001). At the end of the study, the doses of hydroxyurea ranged from 0 to 35 mg per kilogram of body weight per day. Treatment with hydroxyurea did not cause any important adverse effects.

CONCLUSIONS

Hydroxyurea therapy can ameliorate the clinical course of sickle cell anemia in some adults with three or more painful crises per year. Maximal tolerated doses of hydroxyurea may not be necessary to achieve a therapeutic effect. The beneficial effects of hydroxyurea do not become manifest for several months, and its use must be carefully monitored. The long-term safety of hydroxyurea in patients with sickle cell anemia is uncertain.

The impact of prophylaxis on outcome and resource utilization in Pneumocystis carinii pneumonia

STUDY OBJECTIVE

Pneumocystis carinii pneumonia (PCP) is a major late complication of HIV infection associated with morbidity and mortality. Because chemoprophylaxis is highly effective, cases of PCP can be viewed as failures in the management of HIV disease.

METHODS

We reviewed demographic, clinical, and cost data for all cases of confirmed HIV-related PCP at The Johns Hopkins Hospital in 1991 to determine consequences of missed prophylaxis. We also analyzed hospital discharge data for Maryland in 1991 to assess hospital charges, length of stay, and outcome for all patients with a principal diagnosis of HIV-related PCP.

RESULTS

Pneumocystis carinii pneumonia was diagnosed in 79 patients. Of the 79 patients, 61 (77%) did not receive prophylaxis, including 26 who were not previously known to have HIV infection, 17 who did not have prophylaxis prescribed, and 18 who had prophylaxis prescribed, but were not compliant with the regimen. Patients not taking prophylaxis accounted for all 12 deaths ascribed to PCP. This group also accounted for 85% of the hospital days, 100% of the ICU days, and 89% of the inpatient charges. The total hospital charges were $849,540. Extrapolation of these figures for the state of Maryland suggest that the failure to receive prophylaxis in 1991 resulted in 62 patient deaths and a cost of approximately $4.7 million.

CONCLUSION

Patients who developed PCP despite prophylaxis had a better outcome and used fewer resources than patients not receiving preventive therapy. This study emphasizes the impact of PCP prophylaxis on the morbidity, mortality, and economics of HIV health care.

Hospital admissions of HIV-infected patients from 1988 to 1992 in Maryland

To determine how the patterns of inpatient hospital care for HIV-infected patients have evolved in recent years, we analyzed data obtained from a statewide hospital discharge database from Maryland for the years 1988, 1990, and 1992. For each of these years, we compared demography, diagnoses, lengths of stay, use of the intensive care unit, third-party payer, and hospital charges (inflation-adjusted to 1992 dollars). HIV-infected patients accounted for 0.42% of all Maryland's hospital admissions in 1988, 0.68% in 1990, and 1.1% in 1992, with progressively more women and African-Americans hospitalized. Average lengths of stay fell from 11.7 days (1988) to 10.7 days (1990) and 9.5 days (1992) (p < 0.0001). Average charges per admission fell from $11,634 (1988) to $9,938 (1990) and $8,618 (1992) (p < 0.0001). Medicare or Medicaid paid for 50.9% of hospital admissions in 1988, 56.8% in 1990, and 66.8% in 1992 (p < 0.001). In-hospital mortality rates (7.8% in 1988, 7.9% in 1990, and 7.7% in 1992; p = 0.783) were stable, as was severity of illness. P. carinii pneumonia (PCP) was the most common principal diagnosis, but it declined in prevalence from 13.6% in 1988 to 9.1% in 1992 (p < 0.0001). Principal diagnoses of other opportunistic infections remained stable (8.0% in 1988, 9.9% in 1990, 8.6% in 1992; p = 0.90), as did other nonopportunistic infections (32.8% in 1988, 27.2% in 1990, and 30.0% in 1992; p = 0.16). Non-PCP pneumonias increased from 7.6% (1988) to 10.2% (1992) (p < 0.0001). Substance abuse as a principal or secondary diagnosis increased from 30.9% (1988) to 34.3% (1992) (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Studies on new acidic azoles as glucose-lowering agents in obese, diabetic db/db mice

Bioisosteric substitution was used as a tool to generate several new structural alternatives to the thiazolidine-2,4-dione and tetrazole heterocycles as potential antidiabetic agents. Among the initial leads that emerged from this strategy, a family of acidic azoles, isoxazol-3- and -5-ones and a pyrazol-3-one, showed significant plasma glucose-lowering activity (17-42% reduction) in genetically obese, diabetic db/db mice at a dose of 100 mg/kg/day x4. Structure-activity relationship studies determined that 5-alkyl-4-(arylmethyl)pyrazol-3-ones, which exist in solution as aromatic enol/iminol tautomers, were the most promising new class of potential antidiabetic agent (32-45% reduction at 20 mg/kg/d x4). Included in this work are convenient syntheses for several types of acidic azoles that may find use as new acidic bioisosteres in medicinal chemistry such as the antidiabetic lead 5-(trifluoromethyl)pyrazol-3-one (hydroxy tautomer) and aza homologs of the pyrazolones, 1,2,3-triazol-5-ones (hydroxy tautomer) and 1,2,3,4-tetrazol-5-one heterocycles. log P and pKa data for 15 potential acidic bioisosteres, all appended to a 2-naphthalenylmethyl residue so as to maintain a similar distance between the acidic hydrogen and arene nucleus, are presented. This new data set allows comparison of a wide variety of potential acid mimetics (pKa 3.78-10.66; log P -0.21 to 2.76) for future drug design.

An analysis of fetal hemoglobin variation in sickle cell disease: the relative contributions of the X-linked factor, beta-globin haplotypes, alpha-globin gene number, gender, and age

Five factors have been shown to influence the 20-fold variation of fetal hemoglobin (Hb F) levels in sickle cell anemia (SS): age, sex, the alpha-globin gene number, beta-globin haplotypes, and an X-linked locus that regulates the production of Hb F-containing erythrocytes (F cells), ie, the F-cell production (FCP) locus. To determine the relative importance of these factors, we studied 257 Jamaican SS subjects from a Cohort group identified by newborn screening and from a Sib Pair study. Linear regression analyses showed that each variable, when analyzed alone, had a significant association with Hb F levels (P < .05). Multiple regression analysis, including all variables, showed that the FCP locus is the strongest predictor, accounting for 40% of Hb F variation. beta-Globin haplotypes, alpha-globin genes, and age accounted for less than 10% of the variation. The association between the beta-globin haplotypes and Hb F levels becomes apparent if the influence of the FCP locus is removed by analyzing only individuals with the same FCP phenotype. Thus, the FCP locus is the most important factor identified to date in determining Hb F levels. The variation within each FCP phenotype is modulated by factors associated with the three common beta-globin haplotypes and other as yet unidentified factor(s).

Functional status of persons with HIV infection in an ambulatory setting

The objective of this project was to study the functional status of HIV-infected persons seen in an ambulatory care setting. We reviewed baseline clinical and demographic data on patients with HIV infection presenting for care between December 1988 and May 1991 at the HIV Clinic of the Johns Hopkins Hospital, an urban, primary care institution. Functional status was assessed at baseline in a comprehensive psychosocial assessment. Patients were asked to report on their ability to perform six activities of daily living (ADL) and nine instrumental activities of daily living (IADL). The main outcome measures were dependency in one or more ADL and death as ascertained by review of clinic death records and Maryland State Death Registries. All 728 patients had assessments of functional status. Of these, 18% reported dependencies in one or more activity, with most of these (14%) reporting dependencies in IADLs only. Dependencies were more common in persons with an AIDS diagnosis (32% vs. 15%, p < 0.001). The majority of the dependencies reported by AIDS patients were also in IADLs. Mean CD4 counts were lower for persons reporting dependencies than for those who reported no dependencies (p = 0.02). No independent associations were found between functional limitation and demographic variables. The risk of death was greater in patients with dependencies than in patients with no dependencies, even when adjusting for CD4 count and AIDS diagnosis (O.R. = 2.32, p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Prophylaxis for opportunistic infections in patients with HIV infection

OBJECTIVE

To review the efficacy of chemoprophylaxis for opportunistic infections in persons infected with human immunodeficiency virus (HIV).

DATA SOURCES

English-language articles on the prevention of HIV-related opportunistic infections were identified through MEDLINE (1985 to 1993) and through review of abstracts presented at the International Conferences on AIDS, the Interscience Conferences on Antimicrobial Agents and Chemotherapy, and the National Conference on Human Retroviruses and Related Diseases.

STUDY SELECTION

Importance was assigned in descending order to controlled clinical trials, uncontrolled trials and retrospective studies, and prospective observational studies.

DATA SYNTHESIS

Persons infected with HIV who are at risk for Pneumocystis carinii pneumonia should receive prophylaxis, preferably with trimethoprim-sulfamethoxazole. Alternative agents are aerosolized pentamidine, dapsone, and dapsone-pyrimethamine. Patients who are seropositive for Toxoplasma gondii may benefit from primary prophylaxis against toxoplasmosis using trimethoprim-sulfamethoxazole or dapsone-pyrimethamine. Life-long secondary prophylaxis is indicated for all patients previously treated for toxoplasmic encephalitis. Long-term suppressive therapy is required for all patients with cryptococcal meningitis and histoplasmosis, and many patients with recurrent mucosal candidiasis also benefit from long-term suppression. The role of primary prophylaxis of fungal infections, however, is uncertain. Rifabutin has been approved to prevent disseminated infection with Mycobacterium avium complex and is indicated for all patients with CD4 counts less than 100/mm3. Chemoprophylaxis with isoniazid for 12 months is indicated in all patients infected with HIV who have or are at high risk for M. tuberculosis infection. No effective primary prophylactic agent is available for cytomegalovirus disease, although several investigational drugs are being studied. Acyclovir is effective in decreasing recurrences of herpes simplex virus infection. The incidence of common bacterial infections is decreased by trimethoprim-sulfamethoxazole. Pneumococcal polysaccharide vaccine is recommended for adult patients infected with HIV, and Haemophilus influenzae type b conjugate vaccine is recommended for children infected with HIV.

CONCLUSIONS

A growing number of infections related to the acquired immunodeficiency syndrome are preventable with currently available agents. Issues of drug interactions, toxicity, and cost-effectiveness will become increasingly important in the management of patients with advanced HIV disease.

Zidovudine therapy and health resource utilization in AIDS

We wished to determine whether antiretroviral therapy with zidovudine first received when a person is diagnosed with AIDS was associated with diminished or increased direct health resource utilization. As a measure of health resource utilization, we examined all Medicaid-administered health care charges to adult Maryland residents diagnosed with AIDS from 1987 to 1989 who were part of the Human Immunodeficiency Virus Information System. We specifically compared those persons who first received zidovudine therapy either prior to or within 60 days of diagnosis of AIDS (n = 101) with those who never received zidovudine therapy (n = 279). Median survival time after diagnosis of AIDS in those who received zidovudine was 605 days and in those who did not receive zidovudine 235 days. After diagnosis of AIDS, median per-person lifetime direct health care charges to Medicaid were $66,200 in those who received zidovudine and $31,300 in those who did not receive zidovudine. The median incremental charge per year of life gained in zidovudine users was $34,600 compared with nonusers. Adjusting by proportional hazards regression for age, gender, race/ethnicity, HIV transmission risk group, AIDS-defining diagnosis, and length of follow-up, lifetime Medicaid charges were higher in zidovudine receivers. Compared with patients who did not receive zidovudine, patients who first received zidovudine at the time AIDS was diagnosed incurred higher cumulative lifetime charges, associated principally with longer survival time. The rate of resource utilization was not decreased by zidovudine use.

Racial differences in the use of drug therapy for HIV disease in an urban community

BACKGROUND

Guidelines for drug therapy in human immunodeficiency virus (HIV) disease are based primarily on the stage of the disease. To determine whether sociodemographic characteristics of patients influence drug therapy in practice, we analyzed the use of antiretroviral therapy and prophylactic therapy for Pneumocystis carinii pneumonia (PCP) in an urban population infected with HIV.

METHODS

All patients presenting for the first time to our HIV clinic from March 1990 through December 1992 were enrolled. Data on sociodemographic and clinical variables and on drug use were collected at the time of presentation and after six months. We asked whether patients with CD4+ cell counts of 500 or less per cubic millimeter were receiving antiretroviral therapy at the time of presentation, and whether patients with CD4+ cell counts of 200 or less per cubic millimeter were receiving PCP prophylaxis.

RESULTS

Among the 838 patients enrolled, 656 (79 percent) were blacks, 167 (20 percent) were non-Hispanic whites, and 15 (2 percent) were Asian or Hispanic descent or were not racially classified. There were no racial differences in the stage of HIV disease at the time of presentation. However, there were racial disparities in the receipt of antiretroviral therapy: 63 percent of eligible whites but only 48 percent of eligible blacks received such therapy (P = 0.003). PCP prophylaxis was received by 82 percent of eligible whites but only 58 percent of eligible blacks (P < 0.001). There were no significant differences in the receipt of drug therapy with respect to age, sex, mode of HIV transmission, type of insurance, income, education, or place of residence. In a logistic-regression analysis, race was the feature most strongly associated with the receipt of drug therapy. When blacks were compared with whites, the adjusted relative odds were 0.59 (95 percent confidence interval, 0.38 to 0.93) for the receipt of an antiretroviral agent and 0.27 (95 percent confidence interval, 0.13 to 0.56) for the receipt of PCP prophylaxis.

CONCLUSIONS

Among patients infected with HIV, blacks were significantly less likely than whites to have received antiretroviral therapy or PCP prophylaxis when they were first referred to an HIV clinic. This disparity suggests a need for culturally specific interventions to ensure uniform access to care, including drug therapy, and uniform standards of care.