Background context Primary care clinicians need to identify candidates for early interventions to prevent patients with acute pain from developing chronic pain. Purpose We conducted a 2-year prospective cohort study of risk factors for the progression to chronic pain and developed and internally validated a clinical decision rule (CDR) that stratifies patients into low-, medium-, and high-risk groups for chronic pain. Study design/Setting This is a prospective cohort study in primary care. Patient sample Patients with acute low back pain (LBP, ≤30 days duration) were included. Outcome measures Outcome measures were self-reported perceived nonrecovery and chronic pain. Methods Patients were surveyed at baseline, 6 months, and 2 years. We conducted bivariate and multivariate regression analyses of demographic, clinical, and psychosocial variables for chronic pain outcomes, developed a CDR, and assessed its performance by calculating the bootstrapped areas under the receiver-operating characteristic curve (AUC) and likelihood ratios. Results Six hundred five patients enrolled: 13% had chronic pain at 6 months and 19% at 2 years. An eight-item CDR was most parsimonious for classifying patients into three risk levels. Bootstrapped AUC was 0.76 (0.70-0.82) for the 6-month CDR. Each 10-point score increase (60-point range) was associated with an odds ratio of 11.1 (10.8-11.4) for developing chronic pain. Using a less than 5% probability of chronic pain as the cutoff for low risk and a greater than 40% probability for high risk, likelihood ratios were 0.26 (0.14-0.48) and 4.4 (3.0-6.3) for these groups, respectively. Conclusions A CDR was developed that may help primary care clinicians classify patients with strictly defined acute LBP into low-, moderate-, and high-risk groups for developing chronic pain and performed acceptably in 1,000 bootstrapped replications. Validation in a separate sample is needed.

Background

The 9-item STarT-Back screening tool was developed in primary care patients with low back pain (LBP) to identify those at greatest risk for chronic pain and requiring targeted treatment. We conducted a secondary data analysis study to examine the performance of comparable questionnaire items in a sample of primary care patients with well-defined acute LBP.

Methods

In a prospective cohort study, 605 primary care patients with LBP of less than 30 days answered a questionnaire with 6 items identical and 3 items analogous to the 9-item STarT-Back. Participants were followed up at 6 months and 2 years. STarT-Back rules were applied to classify participant's risk of chronic LBP, and the performance of the screening items in predicting outcomes was assessed using likelihood ratios.

Results

The proportion of patients with chronic pain at follow-up was considerably lower (6 months: 22%; 2 years: 25%) than in the STarT-Back validation cohort (40%) of patients with pain of any duration. The probability of developing chronic pain given a high-risk designation by items similar to the STarT-Back increased the pre-test probability to 31% and 35%. Likelihood ratios were close to 1.

Conclusions

A risk classification schema using the recommended cut-off scores with items similar to the STarT-Back in a primary care population with strictly defined acute LBP had limited ability to identify persons who progressed to chronic pain. The results suggest caution when applying the STarT-Back in patients with acute LBP and a need to consider a modification of its cut-offs.

© 2014 The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.We estimate the relative transmission rate in early versus later infection among men who have sex with men (MSM) in San Francisco, Californ

The gastrointestinal mucosa is an important site of HIV acquisition, viral replication, and pathogenesis. Immune cells in mucosal tissues frequently differ in phenotype and function from their non-mucosal counterparts. Although perforin-mediated cytotoxicity as measured in blood is a recognized correlate of HIV immune control, its role in gastrointestinal tissues is unknown. We sought to elucidate the cytotoxic features of rectal mucosal CD8⁺ T-cells in HIV infected and uninfected subjects. Perforin expression and lytic capacity were significantly reduced in rectal CD8⁺ T-cells compared with their blood counterparts, regardless of HIV clinical status; granzyme B (GrzB) was reduced to a lesser extent. Mucosal perforin and GrzB expression were higher in participants not on antiretroviral therapy compared with those on therapy and controls. Reduction in perforin and GrzB was not explained by differences in memory/effector subsets. Expression of T-bet and Eomesodermin was significantly lower in gut CD8⁺ T-cells compared with blood, and in vitro neutralization of TGF-β partially restored perforin expression in gut CD8⁺ T-cells. These findings suggest that rectal CD8⁺ T-cells are primarily non-cytotoxic, and phenotypically shaped by the tissue microenvironment. Further elucidation of rectal immune responses to HIV will inform the development of vaccines and immunotherapies targeted to mucosal tissues.

We used a Stress and Coping model to examine the association of dispositional mindfulness, defined as the tendency to intentionally bring nonjudgmental attention and awareness to one's experience in the present moment, with psychological and physical health in adults with HIV. Data were collected at baseline of a randomized controlled trial of Mindfulness-Based Stress Reduction (MBSR). Four facets of mindfulness (acting with attention/awareness, nonjudging of inner experience, observing, and describing) were examined as correlates of appraisal, positive and negative affect, coping, and indicators of psychological well-being and physical health. We found that mindfulness was inversely related to depression, stress appraisal, and negative affect, and positively related to positive affect. Mindfulness was also inversely related to escape/avoidance and self-blame forms of coping. Mediational analyses indicate that perceived stress and negative affect were the most consistent mediators of the association of mindfulness and psychological well-being. The findings from this paper contribute to a growing understanding of the potential adaptive role of mindfulness in people living with the stress of serious illness.

We recently observed that a large proportion of activated (CD38+HLA-DR+) CD8+ T cells from recently HIV-1-infected adults are refractory to phosphorylation of ERK1/2 kinases (p-ERK1/2-refractory). Given that the ERK1/2 pathway mediates intracellular signal

During HIV-1 infection, immune dysregulation and aberrant lymphocyte functions are well-established characteristics. Cell surface molecules are important for immunological functions and changes in expression can affect lymphocyte effector functions, thereb

A subset of CD3(neg)CD56(neg)CD16 + Natural Killer (NK) cells is highly expanded during chronic HIV-1 infection. The role of this subset in HIV-1 pathogenesis remains unclear. The lack of NK cell lineage-specific markers has complicated the study of minor NK cell subpopulations. Using CD7 as an additional NK cell marker, we found that CD3(neg)CD56(neg)CD16 + cells are a heterogeneous population comprised of CD7 + NK cells and CD7(neg) non-classical myeloid cells. CD7 + CD56(neg)CD16 + NK cells are significantly expanded in HIV-1 infection. CD7 + CD56(neg)CD16 + NK cells are mature and express KIRs, the C-type lectin-like receptors NKG2A and NKG2C, and natural cytotoxicity receptors similar to CD7 + CD56 + CD16 + NK cells. CD7 + CD56(neg) NK cells in healthy donors produced minimal IFNγ following K562 target cell or IL-12 plus IL-18 stimulation; however, they degranulated in response to K562 stimulation similar to CD7 + CD56 + NK cells. HIV-1 infection resulted in reduced IFNγ secretion following K562 or cytokine stimulation by both NK cell subsets compared to healthy donors. Decreased granzyme B and perforin expression and increased expression of CD107a in the absence of stimulation, particularly in HIV-1-infected subjects, suggest that CD7 + CD56(neg)CD16 + NK cells may have recently engaged target cells. Furthermore, CD7 + CD56(neg)CD16 + NK cells have significantly increased expression of CD95, a marker of NK cell activation. Taken together, CD7 + CD56(neg)CD16 + NK cells are activated, mature NK cells that may have recently engaged target cells.

© 2014 Norström et al.HLA-B*5701 is the host factor most strongly associated with slow HIV-1 disease progression, although risk of progression may vary among patients carrying this allele. The interplay between HIV-1 evolutionary rate variation and risk of

Background: A subset of CD3negCD56negCD16+ Natural Killer (NK) cells is highly expanded during chronic HIV-1 infection. The role of this subset in HIV-1 pathogenesis remains unclear. The lack of NK cell lineage-specific markers has complicated the study of minor NK cell subpopulations.Results: Using CD7 as an additional NK cell marker, we found that CD3negCD56negCD16+ cells are a heterogeneous population comprised of CD7+ NK cells and CD7neg non-classical myeloid cells. CD7+CD56negCD16+ NK cells are significantly expanded in HIV-1 infection. CD7+CD56negCD16+ NK cells are mature and express KIRs, the C-type lectin-like receptors NKG2A and NKG2C, and natural cytotoxicity receptors similar to CD7+CD56+CD16+ NK cells. CD7+CD56neg NK cells in healthy donors produced minimal IFNγ following K562 target cell or IL-12 plus IL-18 stimulation; however, they degranulated in response to K562 stimulation similar to CD7+CD56+ NK cells. HIV-1 infection resulted in reduced IFNγ secretion following K562 or cytokine stimulation by both NK cell subsets compared to healthy donors. Decreased granzyme B and perforin expression and increased expression of CD107a in the absence of stimulation, particularly in HIV-1-infected subjects, suggest that CD7+CD56negCD16+ NK cells may have recently engaged target cells. Furthermore, CD7+CD56negCD16+ NK cells have significantly increased expression of CD95, a marker of NK cell activation.Conclusions: Taken together, CD7+CD56negCD16+ NK cells are activated, mature NK cells that may have recently engaged target cells. © 2013 Milush et al.; licensee BioMed Central Ltd.