Incidence of neuropathy in HIV-infected patients on monotherapy versus those on combination therapy with didanosine, stavudine and hydroxyurea

BACKGROUND

Sensory neuropathy is a common adverse effect of the nucleoside analogue anti-retroviral drugs didanosine (ddl) and stauvudine (d4T). These drugs are increasingly being used in combination, and it is not currently known whether the incidence of neuropathy is higher with combination compared to individual drug use. It is also not known if hydroxyurea, used to potentiate the antiviral efficacy of these drugs, may also increase the risk of neuropathy. The purpose of this analysis is to investigate if the combination of ddl and d4T, with or without hydroxyurea, has a higher incidence of neuropathy than a single drug regimen.

METHODS

Data were obtained from patients followed longitudinally by the Johns Hopkins AIDS Services. Incidence rates of development of neuropathy were calculated for each of five regimens: ddl (+/- hydroxyurea), ddl + d4T (+/- hydroxyurea), and d4T. Cox proportional hazard regression was used to compare the relative risk of neuropathy for each regimen adjusting for CD4 cell count, other drugs received, and time on therapy.

RESULTS

A total of 1116 patients received at least one of the five regimens. There were 117 cases of neuropathy. The crude incidence rate of neuropathy ranged from 6.8 cases per 100 person-years for ddl to 28.6 cases per 100 person-years for ddl + d4T + hydroxyurea. Compared with ddl alone, and adjusting for CD4 cell counts and other variables, the relative risk of neuropathy was 1.39 [95% confidence interval (CI): 0.84-2.32] for d4T alone, 2.35 (95% CI: 0.69-8.07) for ddl + hydroxyurea, 3.50 (95% CI: 1.81-6.77) for ddl + d4T, and 7.80 (95% CI: 3.92-15.5) for ddl + d4T + hydroxyurea.

CONCLUSIONS

Based on the data, the risk of neuropathy is additive or even synergistic for ddl + d4T + hydroxyurea compared with ddl or d4T alone. The combination of ddl + d4T also increases the risk of neuropathy but less than when hydroxyurea is included.

Hepatotoxicity associated with antiretroviral therapy in adults infected with human immunodeficiency virus and the role of hepatitis C or B virus infection

CONTEXT

Use of antiretroviral drugs, including protease inhibitors, for treatment of human immunodeficiency virus (HIV) infection has been anecdotally associated with hepatotoxicity, particularly in persons coinfected with hepatitis C or B virus.

OBJECTIVES

To ascertain if incidence of severe hepatotoxicity during antiretroviral therapy is similar for all antiretroviral drug combinations, and to define the role of chronic viral hepatitis in its development.

DESIGN

Prospective cohort study.

SETTING

University-based urban HIV clinic.

PATIENTS

A total of 298 patients who were prescribed new antiretroviral therapies between January 1996 and January 1998, 211 (71%) of whom received protease inhibitors as part of combination therapy (median follow-up, 182 days) and 87 (29%) of whom received dual nucleoside analog regimens (median follow-up, 167 days). Chronic hepatitis C and B virus infection was present in 154 (52%) and 8 (2.7%) patients, respectively.

MAIN OUTCOME MEASURE

Severe hepatotoxicity, defined as a grade 3 or 4 change in levels of serum alanine aminotransferase and aspartate aminotransferase, evaluated before and during therapy.

RESULTS

Severe hepatotoxicity was observed in 31 (10.4%) of 298 patients (95% confidence interval [CI], 7.2%-14.4%). Ritonavir use was associated with a higher incidence of toxicity (30%; 95% CI, 17.9% -44.6%). However, no significant difference was detected in hepatotoxicity incidence in other treatment groups, ie, nucleoside analogs (5.7%; 95% CI, 1.2%-12.9%), nelfinavir (5.9%; 95% CI, 1.2%-16.2%), saquinavir (5.9%; 95% CI, 0.15%-28.7%), and indinavir(6.8%; 95% CI, 3.0%-13.1 %). Although chronicviral hepatitis was associated with an increased risk of severe hepatotoxicity among patients prescribed nonritonavir regimens (relative risk, 3.7; 95% CI, 1.0-11.8), most patients with chronic hepatitis C or B virus infection (88%) did not experience significant toxic effects. Rate of severe toxicity with use of any protease inhibitor in patients with hepatitis C infection was 12.2% (13/107; 95% CI, 6.6%-19.9%). In multivariate logistic regression, only ritonavir (adjusted odds ratio [AOR], 8.6; 95% CI, 3.0-24.6) and a CD4 cell count increase of more than 0.05 x 10(9)/L (AOR, 3.6; 95% CI, 1.0-12.9) were associated with severe hepatotoxicity. No irreversible outcomes were seen in patients with severe hepatotoxicity.

CONCLUSIONS

Our data indicate that use of ritonavir may increase risk of severe hepatotoxicity. Although hepatotoxicity may be more common in persons with chronic viral hepatitis, these data do not support withholding protease inhibitor therapy from persons coinfected with hepatitis B or C virus.

Nitric oxide successfully used to treat acute chest syndrome of sickle cell disease in a young adolescent

OBJECTIVES

To report a case of acute chest syndrome (ACS) of sickle cell disease treated successfully with nitric oxide and to review the physiologic effects of nitric oxide and its potential ability to improve outcome in ACS.

DESIGN

Descriptive case report.

SETTING

Eighteen-bed pediatric intensive care unit in a university children's hospital.

PATIENT

A 15-yr-old black male with sickle cell disease, bilateral pulmonary infiltrates, refractory hypoxemia, and unstable hemodynamics.

INTERVENTION

In addition to exchange transfusion, invasive hemodynamic monitoring, and aggressive ventilatory support, inhaled nitric oxide was administered in the gas mixture in a concentration of 20 ppm for 72 hrs.

MEASUREMENTS AND MAIN RESULTS

Cardiac output, pulmonary arterial pressure, pulmonary artery occlusion pressure, systemic vascular resistance, pulmonary vascular resistance, shunt fraction, and alveolar-arterial oxygen gradient were compared with and without inhaled nitric oxide. Marked reductions in pulmonary arterial pressure and pulmonary vascular resistance were noted. Cardiac output improved, and shunt fraction and alveolar-arterial oxygen gradient were markedly reduced. The patient required decreased ventilator and hemodynamic support and rapidly made a complete recovery.

CONCLUSIONS

Nitric oxide may be beneficial for patients with ACS because of its ability to ameliorate pulmonary hypertension and ventilation/perfusion mismatch. Nitric oxide may confer some protection against polymerization of sickle hemoglobin and exert a reversible antiplatelet effect that may be beneficial in ACS. Further study is necessary to determine the safety and efficacy of inhaled nitric oxide as a treatment for ACS.

Laparoscopic aortic injury leading to delayed aortoenteric fistula: an alternative technique for repair

Complications of laparoscopic procedures occur in up to 10% of cases. The most lethal complication relates to injury of major retroperitoneal vascular structures. A case of aortoenteric fistula referred to the vascular surgical service 1 month following emergency repair of laparoscopic aortic injury is presented. A technique utilizing a saphenous vein panel graft for distal aortic repair is described. Review of reported cases demonstrates that major retroperitoneal vascular injury during laparoscopy is rare, with a reported incidence of 3 to 10/10,000 procedures, and a mortality of up to 20%. Simple suture repair is the usual form of treatment, but specialized techniques are occasionally required.

Natural history of HIV infection in the era of combination antiretroviral therapy

BACKGROUND

The use of protease inhibitor-containing (PI) combination antiretroviral therapy has led to a reduction in the incidence of opportunistic illness and mortality (events) in HIV infection. We wished to quantify the changing incidence of these events in our clinical practice and delineate the relationship between CD4, HIV-1 RNA, and development of events in patients receiving PI combination therapy.

METHODS

We assessed HIV-infected patients with CD4 counts < or =500 cells x10(6)/l. We calculated the incidence of events from 1994 through 1998 and analyzed the association of temporal changes in event incidence and use of antiretroviral therapy. In patients on PI combination therapy, we determined the probability of achieving and maintaining an undetectable HIV-1 RNA response and determined the association of CD4, HIV-1 RNA, and developing an event.

RESULTS

The incidence of opportunistic illness declined from 23.7 events/100 person-years in 1994 to 14.0 events/100 person-years in 1998 (P<0.001). Mortality declined from 20.2 deaths/100 person-years in 1994 to 8.4 deaths/ 100 person-years in 1998 (P<0.001). Use of PI combination therapy was associated with a relative rate of opportunistic illness or death of 0.66 [95% confidence interval (CI), 0.51-0.85; P<0.001]. The relative incidence of each of 16 opportunistic illnesses was approximately the same in 1998 as in 1994 except for lymphoma, cervical cancer and wasting syndrome which do not appeared to have declined in incidence. Approximately 60% of patients who received PI therapy achieved an undetectable HIV-1 RNA, and 65% of these patients maintained durable suppression of HIV-1 RNA. Achieving an undetectable HIV-1 RNA was associated with a decreased risk of an event, and was the variable most strongly associated with an increase in CD4 level. By multivariate analysis, the concurrent CD4 level was most strongly associated with developing an event.

CONCLUSIONS

We observed a significant decline in the incidence of opportunistic illness and death from 1994 through 1998 associated with combination antiretroviral therapy. Patients who develop events while being treated with PI combination therapy were not likely to have achieved an undetectable HIV-1 RNA and are likely to have a low concurrent CD4 level.

Highly active antiretroviral therapy in a large urban clinic: risk factors for virologic failure and adverse drug reactions

BACKGROUND

In clinical trials, highly active antiretroviral therapy (HAART) reduces plasma HIV-1 RNA levels to less than 500 copies/mL in 60% to 90% of patients with HIV-1 infection. The performance of such therapy outside of the clinical trial setting is unclear.

OBJECTIVE

To determine factors associated with failure to suppress HIV-1 RNA levels and adverse drug reactions in a cohort of patients in whom protease inhibitor-containing therapy was begun in a large urban clinic.

DESIGN

Retrospective cohort study.

SETTING

Johns Hopkins HIV Clinic in Baltimore, Maryland.

PATIENTS

273 protease inhibitor-naive patients began taking a protease inhibitor regimen containing at least one other antiretroviral drug to which the patients had not previously been exposed.

MEASUREMENTS

Demographic variables, plasma HIV-1 RNA levels, CD4+ lymphocyte counts, and adverse drug reactions.

RESULTS

Levels of HIV-1 RNA were undetectable in 42% of the cohort at 1 to 90 days, in 44% at 3 to 7 months, and in 37% at 7 to 14 months. Factors associated with failure to suppress viral load at two or more time points included higher rates of missed clinic appointments, nonwhite ethnicity, age 40 years or younger, injection drug use, lower baseline CD4+ lymphocyte count, and higher baseline viral load. In a multivariate model, only higher rates of missed clinic appointments were independently associated with viral suppression at 1 year. Ritonavir was associated with adverse drug reactions about twice as frequently as indinavir or nelfinavir, and women experienced significantly more adverse effects than men.

CONCLUSIONS

Unselected patients in whom HAART is started in a clinic setting achieve viral suppression substantially less frequently than do patients in controlled clinical trials. Missed clinic visits were the most important risk factor for failure to suppress HIV-1 RNA levels. Studies are needed to identify interventions that maximize the performance of HAART in inner-city clinics.

Efficacy of salvage therapy containing ritonavir and saquinavir after failure of single protease inhibitor-containing regimens

OBJECTIVE

To assess the efficacy of salvage therapy containing ritonavir and saquinavir after failure of indinavir- or nelfinavir-containing regimens, and to determine correlates of success or failure.

DESIGN

Retrospective chart review. SETTING. The Moore Clinic - the HIV clinic of Johns Hopkins Hospital.

PATIENTS

Forty-one HIV-infected patients were identified through physician contacts, referrals from other providers, and review of a comprehensive clinical database.

MAIN OUTCOME MEASURES

To determine response to salvage therapy, HIV-1 viral RNA (absolute and log10-transformed) was measured using the Roche Amplicor quantitative HIV-1 RNA assay after initiation of the salvage regimen. Potential correlates of response included: viral RNA at the time of switch; viral RNA at the time of switch as a percentage of baseline viral RNA; magnitude of decline in viral RNA; and the interval between virologic failure of single protease inhibitor therapy and switch to the salvage regimen.

RESULTS

Thirteen (56.5%) of 23 patients failing indinavir responded to salvage therapy (HIV RNA < 400 copies/ml) with persistence throughout the follow-up period (median of 37 weeks; range 18-67 weeks). Mean absolute viral RNA at the time of switch was 20 238 copies/ml (median, 9281) compared with 42 953 copies/ml (median, 24 650) for the 10 non-responders. Mean log10 viral RNA at switch was 3.804 for responders versus 4.405 for non-responders (P = 0.040). Among four responders who had failed nelfinavir, mean viral RNA was 9634 copies/ml and mean log10 viral RNA was 3.749 at the time of switch. Two non-responders had a mean viral RNA of 21 551 and a mean log10 viral RNA of 4.037 at switch.

CONCLUSIONS

In contrast with previous reports, salvage regimens containing ritonavir and/or saquinavir can be effective and durable following the failure of combination regimens containing either indinavir or nelfinavir. Salvage therapy may be more likely to succeed when it is initiated early in failure at low viral loads.

Human immunodeficiency virus infection, anemia, and survival

Anemia, a common hematologic complication in human immunodeficiency virus (HIV)-infected patients, can be caused by mechanisms including infections, neoplasms, or drug treatment. Studies have consistently found anemia to be associated with reduced survival, even when potentially confounding factors were controlled for. Importantly, recovery from anemia has been shown to reduce this risk to approximately the same level as seen among patients never having had anemia. Although anemia traditionally has been treated with blood transfusions, recent studies have shown recombinant human erythropoietin (r-HuEPO) to be effective in elevating hematocrit values and reducing transfusion requirements in HIV-infected patients who have endogenous erythropoietin levels of < or = 500 IU/L. Therapy with r-HuEPO has been shown to be safe and well tolerated. In a recent study, moreover, receipt of erythropoietin was associated with a decreased risk of death, whereas transfusion was associated with an increased risk. If these results are confirmed, the link between r-HuEPO and decreased risk of death in HIV-infected patients with anemia will be further strengthened.

Costs of HIV medical care in the era of highly active antiretroviral therapy

OBJECTIVES

In the USA, Medicaid is the principal payer of the health care costs of patients with HIV infection. We wished to determine how the costs to Medicaid of patients in Maryland infected with HIV have changed in the setting of highly active antiretroviral treatment.

DESIGN

Observational cohort study.

METHODS

Analysis of combined economic and clinical data of patients from the Johns Hopkins HIV Service, the provider of primary and sub-specialty care for a majority of HIV-infected patients in the Baltimore metropolitan region. All patients were enrolled in Medicaid and received care longitudinally in Maryland from 1 January 1995 through 31 December 1997. Monthly Medicaid payments were calculated for all inpatient and outpatient services by fiscal year, CD4 cell count, and use of protease inhibitors.

RESULTS

For inpatients with a CD4 cell count < or = 50 x 10(6) cells/l, the total health care average monthly payments remained unchanged ($2629 in 1995, $2585 in 1997). Total mean monthly payments increased for those with a CD4 cell count > 50 x 10(6) cells/l (CD4 cell count 50-200 x 10(6) cells/l, $1172 in 1995 and $1615 in 1997, P < 0.05; CD4 cell count 201-500 x 10(6) cells/l, $1078 in 1995 and $1305 in 1997, P < 0.05). However, when data were stratified according to use of a protease inhibitor-containing regimen (used during approximately 50% of follow-up time in 1996-1997) it was found that hospital inpatient payments decreased significantly in all CD4 strata for patients on a protease inhibitor-containing regimen whereas pharmacy payments increased significantly. Inpatient payments associated with treating opportunistic illness were lower in 1996-1997 for patients receiving protease inhibitor therapy compared with those not receiving protease inhibitors. On balance, total health care payments tended to be slightly lower for patients receiving a protease inhibitor regimen.

CONCLUSION

Although protease inhibitor-containing antiretroviral regimens are being used by only about half of our Medicaid-insured patients, when they are used, there are significantly lower hospital inpatient and community care costs, as well as lower costs associated with the treatment of opportunistic illness. Even with the concurrent increase in their pharmacy costs, total health care costs were stable or slightly lower for these patients. We believe this is a favorable result suggesting a good clinical value being achieved without an increase in costs.

Risk factors for cryptococcal meningitis in HIV-infected patients

To identify the risk factors for cryptococcal meningitis in patients with HIV disease we conducted a nested case-control study of 37 incident cases of cryptococcal meningitis and 74 controls, identified from a cohort of more than 2000 HIV-infected patients. Conditional logistic regression was used to study demographic and AIDS-related variables in addition to fluconazole and steroid use. No difference in demographic variables, HIV risk factors, or stage of AIDS was detected between cases and controls. Exposure to fluconazole for more than 90 days reduced the risk of cryptococcal meningitis by 82% (OR=0.18; 95% CI=0.04-0.85; p=0.03). We did not find a difference in steroid use between cases and controls for either the length or amount of steroid exposure (p=0.41). No difference in survival during follow-up in the clinic was observed by the log-rank test (p=0.74). Among the cases, a cryptococcal antigen was positive in more than 97% of the CSF or blood samples. CSF and blood cultures were positive in 81 and 44% of the samples, respectively. We conclude that demographic factors did not affect the risk of cryptococcal meningitis in an inner city United States population. While fluconazole use has a protective effect, steroid use was not associated with an increased risk of cryptococcal meningitis in HIV-infected patients.

Tuberculosis vaccination versus isoniazid preventive therapy: a decision analysis to determine the preferred strategy of tuberculosis prevention in HIV-infected adults in the developing world

SETTING

The developing world.

OBJECTIVE

To compare the strategy of TB vaccination with that of tuberculin skin-testing in conjunction with isoniazid (INH) in preventing tuberculosis in HIV-infected persons. For any clinical scenarios in which immunization would be more effective than INH preventive therapy, to determine the minimum necessary vaccine safety and effectiveness required.

DESIGN

Decision analysis. A hypothetical cohort of 10000 HIV-infected persons, 65% of whom were tuberculin positive, living in the developing world, was studied. Probability estimates were based on BCG vaccine for the baseline analysis, and it was assumed that the vaccine cannot protect if given after infection.

RESULTS

Under the probability estimates and assumptions of the analysis, tuberculin skin testing/INH preventive therapy would prevent 458 more cases of TB and 45 more deaths due to TB than TB vaccination. One- and two-way sensitivity analyses revealed no thresholds at which TB vaccination would be the preferred strategy. Vaccine safety did not impact the outcome of the analysis. Three-way sensitivity analysis revealed that if the prevalence of anergy were 35% and the risk of progression to active TB among anergic persons 12.2 cases per 100 person-years, a vaccine would have to be at least 87% effective to be preferred over INH preventive therapy.

CONCLUSIONS

Under the conditions of the analysis, which did not account for cost or logistics, tuberculin skin testing/INH preventive therapy would be more effective than TB vaccination in preventing TB among HIV-infected persons. The hypothesized TB vaccine would prevent more TB than INH preventive therapy only in areas where the prevalence of anergy and risk of active TB if anergic were high, and vaccine effectiveness exceeded 87%.

Stavudine in zidovudine (ZDV)-experienced compared with ZDV-naive patients

OBJECTIVE

To assess the effect of prior zidovudine (ZDV) use on subsequent response to stavudine (D4T)-containing regimens.

DESIGN

Analysis of data from prospective observational database.

METHODS

Patients were ZDV-experienced if they had previously received more than 90 days of ZDV and ZDV-naive if they had never received ZDV. HIV-1 RNA and CD4 cell counts were compared at 3, 6, and 12 months after initiation of D4T. Univariate and multivariate analyses were performed, adjusting for baseline HIV-1 RNA and CD4 cell count, age, sex, race, HIV transmission category, time since enrollment, and protease inhibitor use.

RESULTS

No difference was found between ZDV-experienced (n = 130) and naive (n = 98) patients in age, sex, race, transmission category, use of a concurrent protease inhibitor, or baseline CD4 cell count and HIV-1 RNA. There was no difference in the median decline in HIV-1 RNA (-1.29 log10 copies/ml for experienced patients versus -1.19 log10 copies/ml for naive patients; P = 0.39), in achieving HIV-1 RNA < 400 copies/ml at 3 months (51% versus 49%; P = 0.79) or 6 months (48% versus 56%; P = 0.33). There was no difference in CD4 cell response (+73 x 10(6)/l versus + 87 x 10(6)/l; P = 0.51). By multivariate adjustment in a repeated measures analysis, there was no significant difference in achieving undetectable HIV-1 RNA or in CD4 cell response between experienced and naive patients.

CONCLUSION

No difference in response to a D4T-containing regimen between ZDV-experienced and naive patients was found over a 1-year period. In contrast to previous trials, most patients in this study also received a protease inhibitor. These findings may be more relevant in the current era of highly active antiretroviral therapy.

Can restrictions on reimbursement for anti-ulcer drugs decrease Medicaid pharmacy costs without increasing hospitalizations?

OBJECTIVE

To examine the impact of a policy restricting reimbursement for Medicaid anti-ulcer drugs on anti-ulcer drug use and peptic-related hospitalizations.

DATA SOURCES/STUDY SETTING

In addition to U.S. Census Bureau data, all of the following from Florida: Medicaid anti-ulcer drug claims data, 1989-1993; Medicaid eligibility data, 1989-1993; and acute care nonfederal hospital discharge abstract data (Medicaid and non-Medicaid), 1989-1993.

STUDY DESIGN

In this observational study, a Poisson multiple regression model was used to compare changes, after policy implementation, in Medicaid reimbursement for prescription anti-ulcer drugs as well as hospitalization rates between pre- and post-implementation periods in Medicaid versus non-Medicaid patients hospitalized with peptic ulcer disease.

PRINCIPAL FINDINGS

Following policy implementation, the rate of Medicaid reimbursement for anti-ulcer drugs decreased 33 percent (p < .001). No associated increase occurred in the rate of Medicaid peptic-related hospitalizations.

CONCLUSIONS

Florida's policy restricting Medicaid reimbursement for anti-ulcer drugs was associated with a substantial reduction in outpatient anti-ulcer drug utilization without any significant increase in the rate of hospitalization for peptic-related conditions.

Laparoscopic management of adnexal masses in pregnant women

OBJECTIVE

To report on 14 cases of adnexal masses in the second trimester of pregnancy that were managed with laparoscopic surgery.

STUDY DESIGN

A retrospective study. During the period between January 1994 and January 1998, 14 women presented with adnexal masses in pregnancy and were surgically managed with laparoscopy. A retrospective chart review of these patients was used to determine factors, including gestational age, operating time, length of hospital stay, pathology results, pregnancy outcomes and complications.

RESULTS

Fourteen patients had laparoscopic removal of adnexal masses in their second trimester of pregnancy. Average gestational age was 16 weeks (range, 11.5-21), average operating time was 84 minutes (range, 32-145), and average hospital stay was 2.0 days (range, 1-5). Pathology revealed 4 serous cystadenomas, 3 mucinous cystadenomas, 3 mature teratomas, 3 functional cysts and 1 bilateral endometrioma. There were no postoperative complications except for one case of mild peritonitis, which resolved with expectant management. There were no cases of preterm labor associated with the surgery. Ten pregnancies continued to term without complications and delivered average-sized infants. Three pregnancies were in the third trimester without complications at this writing. There was one intrauterine fetal death at 31 weeks; it was found to be secondary to an acute cord accident on autopsy remote from surgery.

CONCLUSION

Significant ovarian masses are diagnosed relatively frequently in the pregnant woman. The risk of malignancy is low, but complications resulting from distention, rupture and/or torsion of the adnexa can be a significant concern. As laparoscopic procedures improve and our experience with laparoscopy in the pregnant woman increases, most of these patients can forego laparotomy and be managed safely by laparoscopic removal of the mass. This series outlines laparoscopic technique and outcomes after removal of significant adnexal masses in pregnancy.

Schistocytosis and a thrombotic microangiopathy-like syndrome in hospitalized HIV-infected patients

Approximately 150 human immunodeficiency virus (HIV)-infected patients with a thrombotic microangiopathy (TMA)-like syndrome have been reported in the literature since the early 1980s. The prevalence of a TMA-like syndrome in our hospitalized patients was determined to discern whether it is a more common occurrence than previously recognized and, if possible, to delineate risk factors for its occurrence. A total of 350 patients admitted consecutively to the Johns Hopkins Hospital HIV inpatient service were assessed from May 1, 1996 through February 1, 1997. These patients were evaluated for the presence of anemia, thrombocytopenia, fragmented erythrocytes on peripheral blood smear (schistocytosis), renal dysfunction, neurologic dysfunction, and fever. The association of a TMA-like syndrome with demographic and clinical factors was analyzed. Schistocytosis was present in 24% of the patients and a TMA-like syndrome (anemia, thrombocytopenia, schistocytosis + renal dysfunction or neurologic dysfunction, and fever) was present in 7% of the patients. The patients who had a TMA-like syndrome were more likely to have a low CD4 lymphocyte count or CD4 percentage, Centers for Disease Control and Prevention stage C disease, and have bacterial sepsis. Age, race, HIV risk group, other diagnoses, and prescribed drugs were not associated. Patients were more likely to die if they had a TMA-like syndrome, independently of level of immunosuppression. Schistocytosis and a TMA-like syndrome are relatively common in hospitalized HIV-infected patients. This syndrome may contribute to mortality and morbidity, particularly in patients with more advanced disease.

A clinicopathologic analysis of AIDS-related cryptosporidiosis

OBJECTIVE

To characterize the histology of AIDS-associated cryptosporidiosis and identify features that explain the clinical variability.

DESIGN

A retrospective analysis of HIV-positive individuals with cryptosporidiosis who underwent endoscopy at the Johns Hopkins Hospital between 1985 and 1996.

METHODS

The histologic features (intensity of Cryptosporidium infection, inflammation, mucosal damage, copathogens) of gastrointestinal biopsies from 37 HIV-positive individuals with cryptosporidiosis were systematically graded. These histologic features were correlated with the severity of the diarrheal illness obtained from a patient chart review.

RESULTS

Histologic features associated with Cryptosporidium infection include a neutrophilic infiltrate in the stomach, villus blunting in the duodenum, cryptitis and epithelial apoptosis in the colon, and reactive epithelial changes in the stomach and duodenum. The nature and intensity of the inflammatory response varied widely; however, duodenal biopsies from a subset of patients (37%) revealed marked acute inflammation that was associated with concomitant cytomegalovirus infection. Although duodenal infection was common (93% of individuals), infection of other sites was variable (gastric cryptosporidiosis in 40% and colonic cryptosporidiosis in 74%). Widespread infection of the intestinal tract, which included both the large and small intestine, was associated with the most severe diarrheal illness.

CONCLUSIONS

Cryptosporidium infection produces histologic evidence of gastrointestinal mucosal injury. The inflammatory response to the infection is variable, and may be modified by copathogens such as cytomegalovirus. The clinical manifestations are influenced, in part, by the anatomic distribution of the infection, with extensive infections involving both small and large intestines producing the most severe illness.

The effect of acute infectious illnesses on plasma human immunodeficiency virus (HIV) type 1 load and the expression of serologic markers of immune activation among HIV-infected adults

The effect of acute coinfections on plasma human immunodeficiency virus (HIV) load and immune activation markers was evaluated. Thirty-two HIV-infected persons were prospectively enrolled; 18 had pre-illness, acute, and follow-up specimens. Plasma HIV RNA levels were determined by reverse transcriptase-polymerase chain reaction, and serum levels of activation markers, including tumor necrosis factor (TNF)-alpha, soluble (s) TNF receptors (R)-I and -II, interleukin (IL)-2, IL-6, IL-10, sIL-2R, sCD4, and sCD8, were assessed by commercial ELISAs. Median plasma HIV load increased 7. 8-fold during illness (P=.001) and decreased 1.5-fold (P=.01) during convalescence (median, 15 days). Significant virus load reductions were limited to subjects with clinical recovery. By regression analysis, changes in plasma HIV RNA were significantly associated with changes in sTNFR-I, sTNFR-II, and sIL-2R. Increased HIV replication during acute coinfections is associated with in vivo immune activation, which underscores the need to prevent and promptly treat intercurrent illnesses.

The effect of adjunctive corticosteroids for the treatment of Pneumocystis carinii pneumonia on mortality and subsequent complications

OBJECTIVE

To assess the long-term safety of adjunctive corticosteroids in the treatment of Pneumocystis carinii pneumonia (PCP).

DESIGN

Analysis of data from a large prospective observational database.

SETTING

HIV clinic at a large urban teaching hospital.

PATIENTS

One hundred seventy-four patients who developed PCP after being enrolled in the database.

RESULTS

Fifty-three patients (30%) received adjunctive corticosteroids and 121 (70%) did not. Survival did not differ between groups after adjusting for CD4 count (relative risk for adjunctive corticosteroids = 0.74, p = 0.13). There were no differences in the incidence of cytomegalovirus disease (adjunctive corticosteroids: 18.5 cases per 100 person-years vs no adjunctive corticosteroids: 15.7, p = 0.22), Mycobacterium avium complex (23.4 vs 27.0, p = 0.73), cryptococcal meningitis (1.8 vs 4.1, p = 0.58), toxoplasmosis (3.6 vs 11.0, p = 0.28), Kaposi's sarcoma (1.8 vs 2.2, p = 0.92), herpes simplex (27.1 vs 42.7, p = 0.66), herpes zoster (3.8 vs 6.9, p = 0.71), oropharyngeal candidiasis (18.9 vs 10.9, p = 0.09), or non-Hodgkin's lymphoma (3.5 vs 4.2, p = 0.92). Esophageal candidiasis was more common among adjunctive corticosteroid recipients (45.1 vs 26.6, p = 0.01). Results were similar for time to development of opportunistic conditions.

CONCLUSIONS

Adjunctive corticosteroids do not increase mortality or the risk of most common HIV-associated complications.

Anemia and survival in HIV infection

Several clinical studies have suggested that anemia is an independent risk factor for dying in patients with HIV disease. We analyzed data from a large urban HIV clinical practice in Baltimore to assess the annual incidence of anemia, the risk of dying in patients who develop anemia, and the association between recombinant human erythropoietin use to treat anemia and subsequent survival. In 2348 patients observed between 1989 and 1996, 498 (21%) developed at least grade 1 anemia (hemoglobin <9.4 g/dl); 95 (4%) developed grade 4 anemia (hemoglobin <6.9 g/dl). Development of anemia was associated with decreased survival, independent of other prognostic factors. Use of erythropoietin was more likely in patients of nonminority race, those who did not inject drugs, those with a lower CD4 count or AIDS, and those being treated for cytomegalovirus disease (p < .05). Adjusting for these factors as well as severity of anemia, age, diagnosis of opportunistic disease, blood transfusion, and antiretroviral therapy in a time-dependent Cox proportional hazards analysis, erythropoietin use (n=91) was associated with a decreased hazard of dying (relative hazard [RH]=0.57; 95% confidence interval [CII, 0.40-0.81; p=.002). Although we cannot rule out a treatment selection bias, adjusting for available prognostic factors and factors potentially associated with a decision to use erythropoietin suggests that erythropoietin for treatment of anemia is associated with improved survival in HIV disease.

Cryptosporidiosis in patients with AIDS: correlates of disease and survival

Although 10%-15% of patients with AIDS in the United States may acquire cryptosporidium infection, little data exist on clinical or histological characteristics that differentiate clinical outcomes. A case-control study of 83 HIV-positive adult patients with cryptosporidiosis was conducted, as was a histopathologic review of data on gastrointestinal biopsy specimens from 30 patients. Four clinical syndromes were identified: chronic diarrhea (36% of patients), choleralike disease (33%), transient diarrhea (15%), and relapsing illness (15%). A multivariate analysis of data for cases and controls revealed that acquiring cryptosporidiosis was associated with the presence of candidal esophagitis (odds ratio [OR], 2.53; P < .002) and Caucasian race (OR, 6.71; P = .0001) but not with sexual orientation. Cases had a significantly shorter duration of survival from the time of diagnosis than did controls (240 vs. 666 days, respectively; P = .0004), which was independent of sex, race, or or injection drug use. Antiretroviral use was protective against disease (OR, 0.072; P = .0001). All four clinical syndromes were represented among the histological data. There was no statistically significant correlation between histological intensity of infection and clinical severity of illness.

Mycobacterium tuberculosis infection and disease are not associated with protection against subsequent disseminated M. avium complex disease

OBJECTIVE

To determine the relationship between Mycobacterium tuberculosis infection and disease and subsequent disseminated M. avium complex (MAC) disease in HIV-infected persons.

DESIGN

A prospective observational cohort study.

SETTING

The AIDS Linked to the Intravenous Experience (ALIVE) cohort of injecting drug users and the Johns Hopkins Hospital Adult HIV Clinic (JHHAHC).

PARTICIPANTS

HIV-infected persons aged > 18 years with CD4 lymphocytes < 100 x 10(6)/l were followed between July 1989 and 31 October 1996. There were 182 persons in the ALIVE cohort and 1129 persons in JHHAHC who met these criteria.

MAIN OUTCOME MEASURE

The relative risk of disseminated MAC was determined according to a history of prior opportunistic infection, MAC prophylaxis, antiretroviral therapy, M. tuberculosis infection or disease, race, sex, and injecting drug use.

RESULTS

Amongst the 30 patients with active tuberculosis, eight developed disseminated MAC, compared with 208 cases of disseminated MAC amongst 1148 patients without prior M. tuberculosis infection or disease [relative risk (RR), 1.5; 95% confidence interval (CI), 0.8-2.7; P=0.2]. Amongst the 10 patients with extrapulmonary tuberculosis, five developed disseminated MAC (RR, 2.8; 95% CI, 1.5-5.2; P=0.02). Injecting drug use was associated with a decreased risk of disseminated MAC (RR, 0.7; 95% CI, 0.6-0.9; P=0.007). In a logistic regression analysis, disseminated MAC was significantly associated with extrapulmonary tuberculosis and other opportunistic disease, whereas antibiotic prophylaxis and injecting drug use were protective.

CONCLUSIONS

A history of M. tuberculosis infection or disease was not associated with protection against subsequent disseminated MAC disease in HIV-infected persons. However, persons with extrapulmonary tuberculosis were at increased risk for disseminated MAC, particularly at low CD4 cell levels.

Self-reported antiretroviral therapy in injection drug users

CONTEXT

The US Public Health Service and the International AIDS Society-USA recently published recommendations for antiretroviral therapy (ART) for persons infected with human immunodeficiency virus (HIV); however, anecdotal evidence suggests that HIV-infected injection drug users (IDUs) may not be receiving optimal care as defined by the recommendations.

OBJECTIVE

To assess ART use in HIV-infected IDUs.

DESIGN

A cross-sectional survey of self-reported ART use between July 1996 and June 1997 in IDUs.

SETTING

A community-based clinic affiliated with Johns Hopkins University, Baltimore, Md.

PARTICIPANTS

A total of 404 HIV-infected IDUs with CD4+ cell counts less than 0.50 x 10(9)/L recruited into a longitudinal study in 1988 and 1989.

MAIN OUTCOME MEASURE

Self-reported ART use was assessed: no current therapy, monotherapy, or combination therapy with or without a protease inhibitor.

RESULTS

One half (199/404 [49%]) of patients reported no recent ART. A total of 14% (58/404) had monotherapy, 23% (90/404) were receiving combination therapy without a protease inhibitor, and 14% (57/404) had triple-combination therapy with a protease inhibitor. A multivariate analysis of factors associated with ART showed that care continuity and recent HIV-related outpatient visit (odds ratio [OR], 4.30; 95% confidence interval [CI], 2.36-7.81 and OR, 2.84; 95% CI, 1.66-4.88, respectively), CD4+ cell count of less than 0.20 x 10(9) (OR, 2.41; 95% CI, 1.51-3.84), no current drug use and being in drug treatment (OR, 2.16; 95% CI, 1.34-3.47; OR, 2.12; 95% CI, 1.23-3.66, respectively), and unemployment (OR, 2.31; 95% CI, 1.21-4.40) were associated with reporting ART use. In other analysis, less likely to receive protease inhibitors were current drug injectors (OR, 0.5; 95% CI, 0.3-1.0) and those recently incarcerated (OR, 0.2; 95% CI, 0.03-0.9), but patients with acquired immunodeficiency syndrome were more likely to receive protease inhibitors (OR, 2.0; 95% CI, 0.9-4.6). Protease inhibitor use doubled (P<.01) from July and December 1996 to January and June 1997 (7.7% and 14.8%, respectively).

CONCLUSIONS

Those IDUs infected with HIV who were not receiving ART tended to be active drug users without clinical disease who have less contact with health care providers. Although we do not have information on clinical judgment regarding treatment decisions or whether persons were prescribed therapy not taken, the proportion of subjects reporting receiving ART suggests that strategies for improving treatment in this population are indicated. Expanding simultaneous treatment services for HIV infection and substance abuse would enhance the response to these related epidemics.

Utilization of computed tomography in patients hospitalized with community-acquired pneumonia

The objective of the study was to assess the frequency of the use of chest computed tomography in 385 adults hospitalized with community-acquired pneumonia and determine whether the computed tomography examinations yielded additional diagnostic information. Also, if additional information was obtained, the study determined whether it changed the patient's treatment plan.

Adherence to antiretroviral and pneumocystis prophylaxis in HIV disease

BACKGROUND

Medication nonadherence in the treatment of chronic diseases compromises the effectiveness of therapy. Little information is available about the extent of medication adherence or determinants of medication adherence in HIV disease, an issue of increasing importance in this new therapeutic era of combination antiretroviral therapy.

METHODS

We studied 244 HIV-infected Medicaid-insured patients attending an HIV hospital-based clinic regarding the extent of and predictors of adherence to antiretroviral therapy and Pneumocystis carinii pneumonia (PCP) prophylaxis. Patients were asked to report medications being taken, patterns of use, and knowledge and attitudes about HIV therapies. Medical record report of type, dose, and frequency of medication was compared with self-report using the kappa statistic. Urine sulfamethoxazole assay was obtained from patients prescribed sulfamethoxazole-trimethoprim.

RESULTS

Among patients prescribed antiretroviral therapy, 60% reported > or = 80% adherence in the previous 7 days; 49% reported > or = 80% adherence with PCP prophylaxis in the previous seven days. Seventy-nine percent of patients who reported taking daily sulfamethoxazole-trimethoprim had detectable urinary sulfamethoxazole. In multivariate analysis, > or = 80% adherence to antiretroviral therapy was associated with taking medication < or = twice a day (odds ratio [OR]=1.44; 95% confidence interval [CI], 1.01, 1.96), being likely to take medication when not at home, (OR=1.41; 95% CI, 1.04, 2.00) and patients' belief in their ability to adhere to therapy (OR=1.57; 95% CI, 1.13, 2.17). For PCP prophylaxis, > or = 80% adherence was associated with presence of family (OR=2.39; 95% CI, 1.01, 5.63) and patients' belief in their ability to adhere to therapy (OR=2.87; 95% CI, 1.44-1.78). Sociodemographic characteristics and belief in the efficacy of medications were not associated with adherence.

CONCLUSIONS

A relatively low level of adherence to antiretroviral therapy and PCP prophylactic regimens was found. Although our results are principally from patients receiving antiretroviral monotherapy, these findings may have important implications for patients receiving highly active antiretroviral therapy (HAART). Decreasing the complexity of antiretroviral regimens, and working with patients to modify identified barriers to adherence may improve effectiveness of medications and prolong survival.

Understanding the clinical and economic outcomes of HIV therapy: the Johns Hopkins HIV clinical practice cohort

The Johns Hopkins AIDS Service is the principal provider of medical care for HIV-infected patients in Maryland, a state in which the majority of HIV-infected patients live in an urban environment. A component of the HIV service at Johns Hopkins Medical Center is an information system that is used to track longitudinally the ambulatory and inpatient care of HIV-infected patients. Enrollment into this database coincides with first enrollment into the HIV Service. Extensive laboratory, diagnostic, clinical, and pharmaceutical information is collected at enrollment and is updated every 6 months. Outpatient and inpatient medical records, Johns Hopkins Health System automated databases, supplemental medical records from outside facilities, vital records, and patient and provider interviews are all used to obtain the detailed data that are stored on the database. The database also includes an economic component, which was added in 1994. This component links all Maryland state Medicaid claims data to that relating to patients who are insured by the Maryland Medical Assistance program, who account for approximately 60% of patients using the Johns Hopkins HIV Service. This data linkage facilitates detailed quantification of the costs of medical care for the HIV-infected patient throughout the course of the infection. We currently have data on about 3,000 HIV-infected patients representing a heterogeneous mix by race, sex, socioeconomic status, and risk factors for HIV transmission. Our data have been used to address a variety of issues regarding access to, utilization of, and clinical outcomes of HIV therapeutics. Clinical practice data such as ours will be increasingly important as the number and types of antiretroviral and other drugs for HIV infection continue to increase.

Implications for macrolide treatment in community-acquired pneumonia. Hopkins CAP Team

STUDY OBJECTIVES

To identify associated clinical parameters, concurrent respiratory tract infections, and the association between macrolide-based therapy and mortality in patients with community-acquired pneumonia ascribed to atypical.

DESIGN

Secondary analysis of prospective, cross-sectional study.

SETTING

Tertiary care hospital.

PATIENTS

Three hundred eighty-five consecutive patients who were admitted to the Johns Hopkins Hospital from November 11, 1990, through November 10, 1991, and treated for community-acquired pneumonia.

RESULTS

An atypical pathogen was identified in 29 of 385 adults (7.5%). A second pathogen was detected in 16 of 29 patients (55.2%) in whom an atypical pathogen was detected, compared with 13 of 137 patients (9.5%) in whom conventional bacterial pathogens were detected (odds ratio, 10.22; 95% confidence interval, 3.7 to 28.8; p<0.0001). During hospitalization, only four patients (13.8%) with detection of an atypical pathogen received at least 7 days of either a macrolide or tetracycline. No patient identified to have an atypical pathogen died. For patients who either provided paired sera or who died, 24 of 197 (12.2%) had atypical pathogens detected.

CONCLUSIONS

Despite vigorous study methods, atypical pathogens were uncommon in our hospitalized population. A second concurrent respiratory pathogen was identified for most patients with atypical pneumonia. Although macrolide use was rare in this patient population, mortality was zero for patients in whom an atypical pathogen was detected, affirming that macrolide-based therapy need not be routine in the therapeutic management of community-acquired pneumonia.

Cost analysis of alternative approaches to colorectal screening in familial adenomatous polyposis

BACKGROUND & AIMS

The commercial availability of gene testing for familial adenomatous polyposis (FAP) represents an important advance in screening for inherited colon cancer. We investigated the financial impact of this diagnostic tool on colorectal screening for FAP.

METHODS

Decision analysis was used to compare per-person costs with third-party payers of three colorectal screening strategies used to diagnose FAP in at-risk persons. The strategies included conventional serial flexible sigmoidoscopy and two different APC gene testing approaches.

RESULTS

For 1 at-risk relative who begins screening at age 12 years, average screening costs are $2625 when genotyping the proband first, $2674 when genotyping the at-risk relative first, and $3208 for conventional sigmoidoscopy. The cost advantage of genotyping increases as the pedigree size increases. For a pedigree of 5 at-risk relatives, sigmoidoscopy would have to cost less than $85.60 (professional plus facility fee) for conventional screening to compete with genotyping. The cost advantage of genotyping is diminished for at-risk relatives who begin FAP screening at older ages.

CONCLUSIONS

The choice of least expensive FAP screening strategy depends on the cost of flexible sigmoidoscopy, patient age when screening starts, and pedigree size. Genotyping can substantially reduce the cost of FAP screening and, when possible, should start with the proband.

Vancomycin-resistant and vancomycin-susceptible enterococcal bacteremia: comparison of clinical features and outcomes

Vancomycin-resistant Enterococcus (VRE) is a major nosocomial pathogen. We collected clinical and laboratory data on 93 hospitalized adults with VRE bacteremia and 101 adults with vancomycin-susceptible enterococcal (VSE) bacteremia. Risk factors for VRE bacteremia included central venous catheterization, hyperalimentation, and prolonged hospitalization prior to the initial blood culture. VRE-infected patients were less likely to have undergone recent surgery or have polymicrobial bacteremia, suggesting a pathogenesis distinct from traditional VSE bacteremia. Prior exposure to metronidazole was the only significant pharmacologic risk factor for VRE bacteremia. Animal studies suggest metronidazole potentiates enterococcal overgrowth in the gastrointestinal tract and translocation into the bloodstream. An increasing APACHE II score was the major risk factor for death in a multivariate analysis, with VRE status being of only borderline significance.

IRLED-based patient localization for linac radiosurgery

PURPOSE

Currently, precise stereotactic radiosurgery delivery is possible with the Gamma Knife or floor-stand linear accelerator (linac) systems. Couch-mounted linac radiosurgery systems, while less expensive and more flexible than other radiosurgery delivery systems, have not demonstrated a comparable level of precision. This article reports on the development and testing of an optically guided positioning system designed to improve the precision of patient localization in couch-mounted linac radiosurgery systems.

METHODS AND MATERIALS

The optically guided positioning system relies on detection of infrared light-emitting diodes (IRLEDs) attached to a standard target positioner. The IRLEDs are monitored by a commercially available camera system that is interfaced to a personal computer. An IRLED reference is established at the center of stereotactic space, and the computer reports the current position of the IRLEDs relative to this reference position. Using this readout from the computer, the correct stereotactic coordinate can be set directly.

RESULTS

Bench testing was performed to compare the accuracy of the optically guided system with that of a floor-stand system, that can be considered an absolute reference. This testing showed that coordinate localization using the IRLED system to track translations agreed with the absolute to within 0.1 +/- 0.1 mm. As rotations for noncoplanar couch angles were included, the inaccuracy was increased to 0.2 +/- 0.1 mm.

CONCLUSIONS

IRLED technology improves the accuracy of patient localization relative to the linac isocenter in comparison with conventional couch-mounted systems. Further, the patient's position can be monitored in real time as the couch is rotated for all treatment angles. Thus, any errors introduced by couch inaccuracies can be detected and corrected.

Cryptosporidiosis in northeastern Brazilian children: association with increased diarrhea morbidity

To evaluate the impact of Cryptosporidium infection on diarrheal disease burden and nutrition status, a nested case-control study was done among children who were followed from birth in Fortaleza, Brazil. The diarrhea history and growth records of 43 children with a symptomatic diarrhea episode of cryptosporidiosis (case-children) were compared with those of 43 age-matched controls with no history of cryptosporidiosis. After Cryptosporidium infection, case-children < or = 1 year old experienced an excessive and protracted (nearly 2 years) diarrheal disease burden. Case-children < or = 1 year old with no history of diarrhea prior to their Cryptosporidium infection also experienced a subsequent increased diarrheal disease burden with an associated decline in growth. Control subjects experienced no change in their diarrhea burden over time. This study suggests that an episode of symptomatic Cryptosporidium infection in children < or = 1 year of age is a marker for increased diarrhea morbidity.

Impact of opportunistic disease on survival in patients with HIV infection

OBJECTIVE

To assess the impact of opportunistic diseases on survival in patients with HIV disease.

METHODS

A cohort of 2081 patients followed for a mean of 30 months was studied. Time-dependent Cox proportional hazards analyses were performed using incident opportunistic diseases and CD4 cell counts as independent variables.

RESULTS

During follow-up, 730 (35%) patients died. The occurrence of Pneumocystis carinii pneumonia (PCP), cytomegalovirus (CMV) disease, Mycobacterium avium complex (MAC) disease, Candida esophagitis, Kaposi's sarcoma, lymphoma, progressive multifocal leukoencephalopathy (PML), dementia, wasting, toxoplasmosis, and cryptosporidiosis were all significantly associated with death, independently of CD4 cell count (all P<0.001 for opportunistic diseases controlling for CD4 cell count). The magnitude of increased risk was greatest for lymphoma [relative hazard (RH), 7.2], PML (RH, 3.9), MAC (RH, 3.0) and CMV (RH, 2.2). Cryptococcosis (RH, 0.94) and herpes zoster (RH, 0.85) were not associated with death. In a multivariate Cox proportional hazards analysis, MAC [RH, 2.56; 95% confidence interval (CI), 2.1-3.1], CMV (RH, 1.63; 95% CI, 1.3-2.1), toxoplasmosis (RH, 1.85; 95% CI, 1.3-2.6), PCP (RH, 1.29; 95% CI, 1.1-1.5), and CD4 cell count were significantly associated with death. Patients who had opportunistic diseases had significantly greatly monthly declines in CD4 counts (-11 x 10(6)/l per month) than those who did not (-6 x 10(6)/l per month; P <0.001).

CONCLUSION

Most opportunistic diseases increase the risk of death independently of CD4 cell count. These data support the hypothesis that opportunistic diseases enhance HIV pathogenesis and further underscore the importance of prophylaxis.

Prevention of opportunistic infections in the era of improved antiretroviral therapy

Patients with advanced human immunodeficiency virus (HIV) infection who are severely immunosuppressed develop a variety of opportunistic infections that have a significant impact on their well-being, quality of life, health-care costs, and survival. The risk for development of opportunistic infections depends on exposure to potential pathogens, the virulence of the pathogens, the degree of host immunity, and the use of antimicrobial prophylaxis. Many studies have confirmed the benefits of prophylaxis in severely immunosuppressed patients. Factors that affect the use of prophylaxis for prevention of opportunistic infections in HIV-infected patients include the prevalence and potential severity of the disease, ease of treatment if infection occurs, the cost-effectiveness of the prophylactic regimen, and the potential for increased survival, drug toxicity, drug interactions, and emergence of resistance with the regimen. The United States Public Health Service and the Infectious Diseases Society of America (USPHS/IDSA) have established disease-specific recommendations for use of prophylaxis for opportunistic infections in HIV-infected patients. These guidelines identify regimens that are strongly recommended as standards of care, regimens that should be seriously considered in selected patients, and regimens that are not routinely indicated but may be considered in selected patients. Although further study is needed, advances in antiretroviral therapy may have an important impact on the recommendations for prophylaxis and may eventually allow discontinuation of these regimens in patients who regain functional immunity.

Gynecologic causes of the acute abdomen and the acute abdomen in pregnancy

Evaluation of a female patient who presents with an acute abdomen must always consider surgical and gynecologic disorders. Laparoscopy and pelviscopy have had a major impact on the surgical approach in gynecology. Most acute abdomens can now be approached laparoscopically. Certain conditions that are discussed require the traditional laparotomy. Preservation of reproductive capability has a major impact on the wellness of a woman.

Bacteroides fragilis toxin exhibits polar activity on monolayers of human intestinal epithelial cells (T84 cells) in vitro

Strains of Bacteroides fragilis associated with diarrhea in children (termed enterotoxigenic B. fragilis, or ETBF) produce a heat-labile ca. 20-kDa protein toxin (BFT). The purpose of this study was to examine the activity of BFT on polarized monolayers of human intestinal epithelial cells (T84 cells). In Ussing chambers, BFT had two effects. First, BFT applied to either the apical or basolateral surfaces of T84 monolayers diminished monolayer resistance. However, the time course, magnitude, and concentration dependency differed when BFT was applied to the apical versus basolateral membranes. Second, only basolateral BFT stimulated a concentration-dependent and short-lived increase in short circuit current (Isc; indicative of C1- secretion). Time course experiments indicated that Isc returned to baseline as resistance continued to decrease, indicating that these two electrophysiologic responses to BFT are distinct. Light microscopic studies of BFT-treated monolayers revealed only localized cellular changes after apical BFT, whereas basolateral BFT rapidly altered the morphology of nearly every cell in the monolayer. Transmission and scanning electron microscopy after basolateral BFT confirmed a striking loss of cellular microvilli and complete dissolution of some tight junctions (zonula occludens) and zonula adherens without loss of desmosomes. The F-actin structure of BFT-treated monolayers (stained with rhodamine-phalloidin) revealed diminished and flocculated staining at the apical tight junctional ring and thickening of F-actin microfilaments in focal contacts at the basolateral monolayer surface compared to those in similarly stained control monolayers. BFT did not injure T84 monolayers, as assessed by lactic dehydrogenase release and protein synthesis assays. These studies indicate that BFT is a nonlethal toxin which acts in a polar manner on T84 monolayers to stimulate C1- secretion and to diminish monolayer resistance by altering the apical F-actin structure of these cells. BFT may contribute to diarrheal disease associated with ETBF infection by altering epithelial barrier function and stimulating C1- secretion.

Cost-utility analysis of prophylactic treatment with oral ganciclovir for cytomegalovirus retinitis

OBJECTIVE

Cytomegalovirus (CMV) retinitis is a relatively common opportunistic infection in late-stage HIV disease, causing significant morbidity and mortality. Prophylactic use of oral ganciclovir has recently been shown to decrease the incidence of CMV retinitis but is relatively expensive and may not be very well tolerated by many patients. We performed a decision analysis to assess the cost-effectiveness of prophylactic oral ganciclovir therapy.

METHODS

A decision analysis using a Markov approach compared absence of prophylaxis and prophylaxis with oral ganciclovir. Estimates of effectiveness of prophylaxis and costs of illness were obtained from published literature. Drug costs were based on national average wholesale prices. All health care costs were based on 1996 U.S. dollars. Sensitivity analyses were done over ranges of estimates of cost and effectiveness.

RESULTS

Using our baseline estimates of cost and effectiveness, use of oral ganciclovir prophylaxis in patients with CD4 counts <50 cells/mm3 would be associated with average lifetime health care costs of $104,746, compared with $90,985 for no prophylaxis. Using oral ganciclovir, the average quality-adjusted life-years (QALYs) would be 2.05, and the CMV retinitis-free life-years would be 1.64, compared with 1.87 and 1.27, respectively, for no prophylaxis. The incremental cost-utility of oral ganciclovir is $76,676 per year of life saved and $37,542 per year of additional CMV retinitis-free life. Oral ganciclovir would become more cost-effective relative to no prophylaxis if the probability of CMV retinitis while taking oral ganciclovir declined. Oral ganciclovir would be less cost-effective if the cost of treating CMV retinitis declines, if our estimates of quality of life are low, or if the overall incidence of CMV retinitis declines.

CONCLUSIONS

Oral ganciclovir is a less cost-effective approach than several other interventions used for HIV-disease prophylaxis. It would potentially become cost-effective if it is possible to target oral ganciclovir prophylaxis to patients who are most likely to benefit.

Prior antimicrobials and staphylococcal bacteremia in HIV-infected patients

OBJECTIVE

Many drugs used for prophylaxis against opportunistic infections in AIDS also have activity against common bacteria. This study was performed to delineate relationships between prior use of antimicrobials and Staphylococcus aureus bacteremia.

DESIGN

To compare prior exposure to selected antimicrobial drugs in patients who had S. aureus bacteremia and in controls who did not, a nested case-control study was conducted within a cohort of HIV-infected persons followed in an outpatient clinic.

METHODS

Using a computerized database based on HIV clinic records, 48 cases with S. aureus bacteremia were compared against 188 controls selected from patients with CD4 cell counts < 200 x 10(6)/l. Information on demographic risk factors and antimicrobial drug use was analysed using conditional logistic regression.

RESULTS

Injecting drug use was strongly associated with S. aureus bacteremia. Rifabutin use was associated with decreased risk of S. aureus bacteremia [conditional relative risk (RR) 0.308, 95% confidence interval (CI) 0.096-0.991] in univariate analysis, near statistical significance in multivariate analysis (RR 0.314, 95% CI 0.096-1.023). The bacteremias were not significantly associated with use of trimethoprim-sulfamethoxazole, quinolones, newer macrolides (azithromycin and clarithromycin), clindamycin or dapsone.

CONCLUSIONS

Rifabutin may be associated with diminished risk of S. aureus bacteremia incidental to use for other purposes in HIV infection. Further study is needed to assess effects on microbial resistance.

The impact of neurologic disease on hospitalizations related to human immunodeficiency virus infection in Maryland, 1991-1992

OBJECTIVES

To determine the impact of neurologic disease on length of stay and total hospital charges for hospitalizations related to human immunodeficiency virus (HIV) infection.

DESIGN

Review of all HIV-related hospitalizations from all acute nonfederal hospitals in Maryland in 1991 and 1992. Neurologic status and HIV disease status were determined by codes from the International Classification of Diseases, Ninth Revision Clinical Modification, in an administrative database. Total hospital charges and length of stay were also included in this database.

RESULTS

Of 12 128 HIV-related hospitalizations (6013 patients with the acquired immunodeficiency syndrome [AIDS], 308 HIV-seropositive patients with symptoms without AIDS, and 5807 HIV-seropositive patients without symptoms), neurologic disease occurred in 1013 (8.4%), predominantly in patients with AIDS. In all HIV-seropositive patients, those with primary neurologic disease had a long mean (+/- SD) length of stay (16.4 +/- 16.5 days vs 9.3 +/- 11.3 days; P < .001) and higher mean (+/- SD) total charges ($12,733 +/- $12,009 vs $8069 +/- $11,247; P < .001) than those without neurologic disease. In patients with AIDS, those with primary neurologic disease also had a longer mean (+/- SD) length of stay (17.2 +/- 17.2 days vs 11.7 +/- 12.7 days; P < .001) and higher mean (+/- SD) total charges ($13,430 +/- $12,470 vs $10,794 +/- $13,537; P < .001) than those without neurologic disease. After adjustment for age, sex, race, and stage of HIV infection in all HIV-seropositive patients, our results indicated that neurologic disease increased the length of stay by 3.3 days (95% confidence interval [CI], 2.9-3.8) and total charges by $2552 (95% CI, $2111-$2993). After adjustment for age, sex, and race in discharged patients with AIDS, the results showed that neurologic disease increased length of stay by 2.24 days (95% CI, 0.73-3.77) and total charges by $1512 (95% CI, $40-$2894).

CONCLUSION

Neurologic disease increases the length of stay and total hospital charges of HIV-infected patients.

Acyclovir in combination with zidovudine does not prolong survival in advanced HIV disease

The aim of this study was to evaluate the association between acyclovir use and survival in HIV-infected patients. To achieve this, we used survival analysis in an observational cohort of HIV-infected patients enrolled in primary care at an urban HIV clinic. We measured survival in a cohort of HIV-infected patients who had CD4 cell counts < or = 500/mm3 and who enrolled for care at a single urban HIV clinic between December 1988 and April 1995. We compared survival in users of acyclovir alone, zidovudine alone, and acyclovir and zidovudine in combination with the survival of those using neither drug. Factors associated with improved survival were identified using Cox proportional hazards analysis. Among the 1408 patients enrolled, there were no significant differences in overall survival between acyclovir users and non-users. After adjustment for CD4 cell count, the use of other antiretroviral agents, race, transmission risk and a history of herpesvirus infection, acyclovir use alone was independently associated with a relative hazard (RH) of death of 1.008 (P = 0.969); zidovudine use alone with a RH of 0.559 (P < 0.001); and combination use of acyclovir and zidovudine associated with a RH of 1.062 (P = 0.788). Therefore we conclude that the use of acyclovir is not associated with prolonged survival in this cohort of HIV-infected patients.

Costs to Medicaid of advancing immunosuppression in an urban HIV-infected patient population in Maryland

Human immunodeficiency virus (HIV) infection is increasingly an urban disease in the United States, and Medicaid is the principal payer of the health care costs of patients with HIV. We wished to determine the costs to Medicaid of patients in Maryland infected with HIV as immunosuppression progresses, and to determine how costs varied by demographic characteristics of the patient. We analyzed combined economic and clinical data in patients from the Johns Hopkins HIV Service, the provider of primary and specialty care for a majority of HIV-infected patients in the Baltimore metropolitan region. All patients were enrolled in Medicaid and received care longitudinally in Maryland from July 1992 to June 1995. Monthly Medicaid payments were calculated for all inpatient and outpatient services by sex, race, age, use of injecting drugs, CD4+ count (>500, 201-500, 51-200, < or =50 cells/mm3), several opportunistic diseases, and death. Lifetime costs were also calculated by use of a Markov simulation. During 13,174 person-months of follow-up in 606 patients, a total of $18,223,700 in Medicaid payments was made. Mean monthly payments ranged from $2,436 (SE $171) for patients with CD4+ counts < or =50 cells/mm3 to $1,015 (SE $177) for patients with CD4+ counts >500 cells/mm3. Mean monthly inpatient costs ranged from $1,355 (SE $131) for CD4+ counts < or =50 cells/mm3 and $617 (SE $164) for CD4- counts >500 cells/mm3. For those with CD4+ counts < or =50 cells/mm3, outpatient pharmacy costs averaged $515 (SE $57) monthly, second only to inpatient costs. In bivariate analysis, costs were significantly higher (p = .013) in men (mean $1696; SE $126) than in women (mean $1,208; SE $101), though the difference was not significant with multivariate adjustment. Cytomegalovirus retinitis was the most costly opportunistic disease, with mean monthly costs of $7,825 (SE $1,141) within the 6 mo after diagnosis. Within 6 mo of death, mean monthly costs are $4,600 (SE $424). Lifetime costs for treating an HIV-infected patient who presents with a CD4+ count >500 cells/mm3 are $133,500 over 8.3 years of life. We concluded that in the clinic where the analysis was done, average costs to Medicaid of treating patients increase more than two-fold as the CD4+ count declines from >500 cells/mm3 to < or =50 cells/mm3. Interventions that decrease hospitalization, opportunistic disease, and the costs of terminal care may be most likely to decrease overall costs. Demographic patient characteristics do not affect costs significantly when access to care is comparable.

Infection due to fluconazole-resistant Candida in patients with AIDS: prevalence and microbiology

A cross-sectional study was conducted to assess the prevalence and microbiology of oral infection due to fluconazole-resistant Candida in patients with AIDS. Oral swab specimens for fungal cultures were obtained from 100 consecutive outpatients with CD4 lymphocyte counts of < 200/mm3. At least one fungal organism demonstrating in vitro resistance to fluconazole (minimum inhibitory concentration, > or = 8 micrograms/mL) was isolated from 26 (41%) of 64 patients for whom cultures were positive. When fluconazole-resistant C. albicans was isolated, in vitro resistance correlated with clinical thrush. None of 10 patients from whom only non-albicans species of Candida were isolated had active thrush. The patients from whom fluconazole-resistant Candida albicans was isolated had lower CD4 cell counts (median, 9/mm3), a greater number of treated episodes of thrush (median, 4.5), and a greater median duration of prior fluconazole treatment (231 days) than did patients from whom fluconazole-susceptible C. albicans was isolated (median CD4 cell count, 58/mm3 [P = .004]; median number of treated episodes of thrush, 2.0 [P = .001]; and median duration of prior fluconazole treatment, 10 days [P = .01]; respectively). In a multivariate analysis, the number of episodes and duration of fluconazole therapy were independent predictors of resistance.

Hydroxyurea and sickle cell anemia. Clinical utility of a myelosuppressive "switching" agent. The Multicenter Study of Hydroxyurea in Sickle Cell Anemia

Painful crises in patients with sickle cell anemia are caused by vaso-occlusion and infarction. Occlusion of blood vessels depends on (at least) their diameter, the deformability of red cells, and the adhesion of blood cells to endothelium. Deoxygenated sickle cells are rigid because they contain linear polymers of hemoglobin S (Hb S); polymerization is highly concentration dependent, and dilution of Hb S by a nonsickling hemoglobin such as fetal hemoglobin (Hb F) would be expected to lead ultimately to a decrease in the frequency of painful crises. It might also be expected to decrease the severity of anemia, although the pathogenesis of anemia in sickle cell anemia (SS disease) is not clearly understood. Reversion to production of fetal rather than adult hemoglobin became practical with the discovery that HU was an orally effective and relatively safe "switching agent." Preliminary dose-ranging studies led to a double-blind randomized controlled clinical trial, the Multicenter Study of Hydroxyurea in Sickle Cell Anemia (MSH), designed to test whether patients treated with HU would have fewer crises than patients treated with placebo. The MSH was not designed to assess the mechanism(s) by which a beneficial effect might be achieved, but it was hoped that observations made during the study might illuminate that question. The 2 MSH treatment groups were similar to each other and were representative of African-American patients with relatively severe disease. The trial was closed earlier than expected, after demonstration that median crisis rate was reduced by almost 50% (2.5 versus 4.5 crises per year) in patients assigned to HU therapy. Hospitalizations, episodes of chest syndrome, and numbers of transfusions were also lower in patients treated with HU. Eight patients died during the trial, and treatment was stopped in 53. There were no instances of alarming toxicity. Patients varied widely in their maximum tolerated doses, but it was not clear that all were taking their prescribed treatments. When crisis frequency was compared with various clinical and laboratory measurements, pretreatment crisis rate and treatment with HU were clearly related to crisis rate during treatment. Pretreatment laboratory measurements were not associated with crisis rates during the study in either treatment group. It was not clear that clinical improvement was associated with an increase in Hb F. Crisis rates of the 2 treatment groups became different within 3 months. Mean corpuscular volumes (MCVs) and the proportion of Hb F containing red cells (F cells) rose, and neutrophil and reticulocyte counts fell, within 7 weeks. When patients were compared on the basis of 2-year crisis rates, those with lower crisis rates had higher F-cell counts and MCVs and lower neutrophil counts. Neutrophil, monocyte, reticulocyte, and platelet counts were directly associated, and F cells and MCV were inversely associated, with crisis rates in 3-month periods. In multivariable analyses, there was strong evidence of independent association of lower neutrophil counts with lower crisis rates. F-cell counts were associated with crisis rate only in the first 3 months of treatment; MCV showed an association over longer periods of time. Overall, the evidence that decreased neutrophil counts played a role in reducing crisis rates was strong. Increased F cells or MCV and evidence of cytoreduction by HU were also associated with decreased crisis rates, but no definitive statement can be made regarding the mechanism of action of HU because the study was not designed to address that question. Future studies should be designed to explore the mechanism of action of HU, to identify the optimal dosage regimen, and to study the effect of HU when combined with other antisickling agents.

Cost-effectiveness of directly observed versus self-administered therapy for tuberculosis

Decision analysis was used to compare three alternative strategies for a 6-mo course of treatment for tuberculosis: directly observed drug therapy (DOT), self-administered fixed-dose combination drug therapy, and self-administered conventional individual drug therapy. Estimates of effectiveness were obtained from the published literature. Estimates of costs were obtained from the literature and the Baltimore City Health Department. Both DOT and fixed-dose combination therapy were less costly and more effective than conventional therapy, although DOT was most cost-effective. In total, the average cost per patient treated was $13,925 for DOT, $13,959 for fixed-dose combination therapy, and $15,003 for conventional therapy. Per 1,000 patients treated, 31 relapses and three deaths could be expected for DOT, 96 relapses and eight deaths for fixed-dose combination therapy, and 133 relapses and 13 deaths for conventional therapy. The marginal cost-effectiveness of DOT relative to fixed-dose combination therapy was most sensitive to variability in the direct cost of DOT and less sensitive to relapse rates for DOT and fixed-dose combination therapy. The inferior cost-effectiveness of conventional therapy was not sensitive to plausible variability in cost or effectiveness. Both DOT and fixed-dose combination therapy were cost-effective relative to conventional therapy, although DOT is probably most cost-effective.

Adverse events from drug therapy for human immunodeficiency virus disease

PURPOSE

Drug therapies for patients with human immunodeficiency virus (HIV) infection are associated with adverse events that can potentially limit their effectiveness. We sought to quantify the incidence of these events in clinical practice and determine whether there were demographic and clinical differences in adverse event rates for these drugs.

PATIENT AND METHODS

We calculated specific and overall adverse event rates from use of zidovudine, didanosine, zalcitabine, cotrimoxazole, and dapsone in an observational urban cohort of 1,450 HIV-infected patients with a CD4+ count of 500 cells/mm3 or less. We compared adverse event rates by gender, race, age, injecting drug use, and CD4+ count.

RESULTS

Overall adverse event rates in order of incidence were dapsone, 16.2 per 100 person-years (PY); didanosine, 24.1 per 100 PY; zidovudine, 26.3 per 100 PY; cotrimoxazole, 26.3 per 100 PY; and zalcitabine, 37.0 per 100 PY. Rates increased significantly with decline in CD4+ count from > 200 to < 100 cells/mm3 for all drugs but dapsone. In addition, women were more likely than men to have an adverse event for didanosine (relative risk [RR] = 2.7, P = 0.03) and from cotrimoxazole (RR 1.5; P = 0.05). Whites were at greater risk than blacks for adverse events from cotrimoxazole (RR = 1.6, P = 0.03). Only 22 of 357 total events (6%) required hospitalization, and there were no deaths.

CONCLUSIONS

Adverse events from antiretroviral drugs and Pneumocystis carinii pneumonia prophylaxis that interrupt therapy are relatively common, although serious events requiring hospitalization are rare. Adverse event rates increase progressively with decline in CD4+ count. The gender and race of the patient modify the risk of adverse events for some drugs.

Duration of the survival benefit of zidovudine therapy in HIV infection

BACKGROUND

Zidovudine therapy improves survival in advanced human immunodeficiency virus (HIV) infection and delays progression from earlier stages to advanced stage of HIV disease. The duration of the benefit of zidovudine therapy, however, may be limited.

OBJECTIVE

To quantitate the duration of the survival benefit of zidovudine therapy in a heterogeneous patient population receiving care for HIV infection in an urban clinic.

METHODS

We analyzed data from 393 HIV-infected patients with CD4+ cell counts of 0.5 x 10(9)/L (500 cells/microliter.) or less who first presented for care at The Johns Hopkins HIV Clinic, Baltimore, Md, from July 1989 through December 1993. Follow-up extended to a maximum of 3 years (median, 2 years). Survival probabilities in patients who received and who did not receive zidovudine therapy were analyzed by Kaplan-Meier methods and by multivariate Cox proportional hazards regression analysis adjusting for both time-dependent and fixed prognostic covariates.

RESULTS

Adjusting for baseline differences in CD4+ cell count, clinical stage of HIV disease, and prophylaxis for Pneumocystis carinii pneumonia, Cox regression analysis showed a significant effect of zidovudine compared with no treatment on the risk of dying during the first year of therapy (relative hazard for death, 0.32; 95% confidence interval [CI], 0.18 to 0.59). However, analysis of the time-dependent effect of zidovudine therapy showed that there was a diminishing relative hazard between treatment and no treatment of 0.75 (95% CI, 0.45 to 1.26) at 1 to 2 years of therapy and a relative hazard of 1.61 beyond 2 years (95% CI, 0.70 to 3.71).

CONCLUSION

The survival advantage of zidovudine therapy is time dependent, lasting between 1 and 2 years in patients with CD4+ cell counts of 0.5 x 10(9)/L or less. Alternative antiretroviral treatment may be indicated at that time.

Effects of an incentive and education program on return rates for PPD test reading in patients with HIV infection

To determine the impact of a food voucher incentive and patient education program on compliance with tuberculin skin test (PPD, purified protein derivative) performance in HIV-infected adults, we analyzed return rates for PPD reading for patients at our urban HIV clinic. The groups studied included patients who received no intervention (controls), patients offered a food voucher incentive, and patients offered a food voucher and patient education intervention. Return rates for PPD reading were 96 (35%) of 272 for the control group, 111 (48%, p = 0.004) of 229 for the food voucher group, and 96 (61%, p < 0.0001) of 158 for the food voucher and patient education group. By univariate analysis, black patients (p = 0.01), males (p = 0.01), older patients (p = 0.04), city residents (p = 0.001), and injection drug users were more likely to return for PPD reading. By logistic regression, food voucher, food voucher plus education, city residence, and male sex were significantly associated with return for PPD reading. Two simple, inexpensive interventions were found to increase compliance with tuberculin skin test performance in HIV-infected adults. Additional interventions are required to achieve better rates of return for PPD reading.