Superior Sensitivity of Ex Vivo IFN‐γ Release Assays as Compared to Skin Testing in Immunocompromised Patients

Comparative assessment of the tuberculin skin testing (TST) and commercial IFN‐γ release‐assays (IGRAs) is hampered by the use of different antigens (tuberculin PPD in TST vs. ESAT‐6/CFP‐10 in IGRAs). Thus, PPD was used as a common stimulus to compare performance of the TST and three IGRAs in 72 controls, 101 hemodialysis patients and 100 renal transplant recipients. Results of the TST were compared with PPD‐induced IFN‐γ induction in vitro detected by ELISPOT, ELISA or a flow‐cytometric FACS assay. Percentages of positive tests were significantly lower in TST (9.2%) compared to ELISA (55.3%), ELISPOT (45.3%) and FACS (44.9%, p < 0.0001). Agreement between TST and IGRAs was highest for controls (κ = 0.19–0.32) and poor in immunocompromised patients (κ = 0 for transplant patients, κ = 0.06–0.13 for hemodialysis patients). Discrepant results were largely TST negative and IGRA positive. Among IGRAs, agreement was highest between ELISPOT and FACS (κ = 0.61). Unlike TST, all IGRAs were associated with variables of mycobacterial exposure. Among IGRAs, the FACS assay was least affected by the level of immunosuppression. In conclusion, both the percentage of positive results and between‐test‐agreement were higher with IGRAs as compared to TST. This indicates superiority of IGRAs in detecting a PPD‐specific immune response which may also apply for immunity toward Mycobacterium tuberculosis–specific antigens.     

The Kaiser Permanente Shoulder Arthroplasty Registry: Results from 6,336 primary shoulder arthroplasties

Background and purpose

Shoulder arthroplasty is being performed in the United States with increasing frequency. We describe the medium-term findings from a large integrated healthcare system shoulder arthroplasty registry.

Patients and methods

Shoulder arthroplasty cases registered between January 2005 and June 2013 were included for analysis. The registry included patient characteristics, surgical information, implant data, attrition, and patient outcomes such as surgical site infections, venous thromboembolism, and revision procedures.

Results

During the study period, 6,336 primary cases were registered. Median follow-up time for all primaries was 3.3 years; 461 cases were lost to follow-up by ending of health plan membership. Primary cases were predominantly female (56%) and white (81%), with an average age of 70 years. The most common reason for surgery was osteoarthritis in 60% of cases, followed by acute fracture (17%) and rotator cuff tear arthropathy (15%). In elective shoulder arthroplasty procedures, 200 all-cause revisions (4%) were reported, with glenoid wear being the most common reason.

Interpretation

Most arthroplasties were elective procedures: over half performed for osteoarthritis. Glenoid wear was the most common reason for revision of primary shoulder arthroplasty in elective cases.In the period 2000 through 2010, over 200,000 shoulder arthroplasties were performed in the USA for osteoarthritis (Trofa et al. 2014). With the increasing use of shoulder arthroplasty (SA) over the past decade (Kim et al. 2011) and projections that future growth rates of SA may exceed those of hip and knee arthroplasty (Day et al. 2010), the need to track the outcomes of SA is becoming increasingly important.Arthroplasty registries provide an important mechanism for tracking surgical outcomes. In the fields of total hip arthroplasty and total knee arthroplasty, registries have demonstrated their importance in monitoring revisions, complications, and mortality, identifying outlier prostheses, and improving quality of care (Graves et al. 2004, Herberts and Malchau 2000, de Steiger et al. 2013, Paxton et al. 2010). SA registries have also provided critical information about demographics, survival, and outlier implants, though there have been considerably fewer publications from the younger national SA registries than from the more established hip and knee registries (Clitherow et al. 2014, Young et al. 2013, Rasmussen et al. 2012a, Rasmussen et al. 2014a and b, Fevang et al. 2009, Fevang et al. 2013). The lack of a national US registry emphasizes the need to use existing US registries to conduct international comparisons of SA patients, implants, surgical techniques, and outcomes. We present the medium-term findings of a large integrated healthcare system SA registry.     

Clinics in diagnostic imaging (162). Meckel’s diverticulum

A 28-year-old Chinese man presented with acute bleeding per rectum. Computed tomography showed a posterior outpouching arising from the distal ileum. The outpouching had hyperaemic walls, but no active contrast extravasation was detected. Technetium-99m pertechnetate scintigraphy showed focal areas of abnormal uptake in the right side of the pelvis, superior and posterior to the urinary bladder. These areas of uptake appeared simultaneously with the gastric uptake and demonstrated gradual increase in intensity on subsequent images. The diagnosis of Meckel’s diverticulum was confirmed on surgery and the lesion was resected. The clinical and imaging features of Meckel’s diverticulum are discussed.