Publications

HIV-1 persists in peripheral blood monocytes in individuals receiving highly active antiretroviral therapy (HAART) with viral suppression, despite these cells being poorly susceptible to infection in vitro. Because very few monocytes harbor HIV-1 in vivo, we considered whether a subset of monocytes might be more permissive to infection. We show that a minor CD16+ monocyte subset preferentially harbors HIV-1 in infected individuals on HAART when compared with the majority of monocytes (CD14highCD16-). We confirmed this by in vitro experiments showing that CD16+ monocytes were more susceptible to CCR5-using strains of HIV-1, a finding that is associated with higher CCR5 expression on these cells. CD16+ monocytes were also more permissive to infection with a vesicular stomatitis virus G protein-pseudotyped reporter strain of HIV-1 than the majority of monocytes, suggesting that they are better able to support HIV-1 replication after entry. Consistent with this observation, high molecular mass complexes of apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G (APOBEC3G) were observed in CD16+ monocytes that were similar to those observed in highly permissive T cells. In contrast, CD14highCD16- monocytes contained low molecular mass active APOBEC3G, suggesting this is a mechanism of resistance to HIV-1 infection in these cells. Collectively, these data show that CD16+ monocytes are preferentially susceptible to HIV-1 entry, more permissive for replication, and constitute a continuing source of viral persistence during HAART.

OBJECTIVE

To evaluate the associations between Medicaid insurance and distance traveled by patients to treating physicians and health care utilization for patients with systemic lupus erythematosus (SLE).

METHODS

A total of 982 adults with SLE were recruited between 2002 and 2004. We calculated the distance between patient homes and physicians using Mapquest, an Internet mapping program. We then assessed the association between Medicaid status and distance traveled to the primary SLE provider, presence of > or =1 physician visits, and the number of all physician visits, with and without adjustment for demographic and medical covariates.

RESULTS

On an unadjusted basis, Medicaid patients traveled longer distances to see their primary SLE provider. This effect was pronounced for patients under the care of a rheumatologist. Adjustment reduced, but did not eliminate, these differences. With adjustment for covariates, Medicaid patients were equally as likely to see a rheumatologist as non-Medicaid patients. However, Medicaid patients were more likely to be seen by a general practitioner or in the emergency room for their SLE, and reported more visits to general practitioners and the emergency room for SLE.

CONCLUSION

Medicaid patients with SLE traveled longer distances to see an SLE physician, especially rheumatologists. They also reported a different pattern of health care utilization. These results suggest that Medicaid patients may face barriers in obtaining comprehensive medical services in proximity to their residences.

OBJECTIVE

To examine the role of sociodemographic factors (age, race/ethnicity, and sex) and socioeconomic factors (income and education) in the utilization of rheumatology subspecialty care in a large cohort of subjects with systemic lupus erythematosus (SLE).

METHODS

Data were derived from a cohort of 982 English-speaking subjects with SLE. Between 2002 and 2004, trained survey workers administered a telephone survey to subjects eliciting information regarding demographics, SLE disease status, medications, health care utilization, health insurance, and socioeconomic status. We identified predictors of utilization of rheumatology subspecialty care, defined as at least 1 visit to a rheumatologist in the previous year. In addition, we examined factors associated with identifying any specialist as primarily responsible for SLE care.

RESULTS

Older age, lower income, Medicare insurance, male sex, and less severe disease were associated with lack of rheumatology care. However, race/ethnicity and educational attainment were not significantly related to seeing a rheumatologist. After multivariate adjustment, only older age, lower income, and male sex remained associated with absence of rheumatology visits. Those least likely to identify a specialist as primarily responsible for their SLE care included older subjects and those reporting lower incomes.

CONCLUSION

Although elderly subjects and those with lower incomes traditionally have access to health care through the Medicare and Medicaid programs, the presence of health insurance alone did not ensure equal utilization of care. This finding suggests that additional barriers to accessing rheumatology subspecialty care may exist in these patient populations.