A multiplexed assay for quantifying immunomodulatory proteins supports correlative studies in immunotherapy clinical trials

Introduction

Immunotherapy is an effective treatment for a subset of cancer patients, and expanding the benefits of immunotherapy to all cancer patients will require predictive biomarkers of response and immune-related adverse events (irAEs). To support correlative studies in immunotherapy clinical trials, we are developing highly validated assays for quantifying immunomodulatory proteins in human biospecimens.

Methods

Here, we developed a panel of novel monoclonal antibodies and incorporated them into a novel, multiplexed, immuno-multiple reaction monitoring mass spectrometry (MRM-MS)-based proteomic assay targeting 49 proteotypic peptides representing 43 immunomodulatory proteins.

Results and discussion

The multiplex assay was validated in human tissue and plasma matrices, where the linearity of quantification was >3 orders of magnitude with median interday CVs of 8.7% (tissue) and 10.1% (plasma). Proof-of-principle demonstration of the assay was conducted in plasma samples collected in clinical trials from lymphoma patients receiving an immune checkpoint inhibitor. We provide the assays and novel monoclonal antibodies as a publicly available resource for the biomedical community.

Androidal fat dominates in predicting cardiometabolic risk in postmenopausal women

We hypothesized that soy isoflavones would attenuate the anticipated increase in androidal fat mass in postmenopausal women during the 36-month treatment, and thereby favorably modify the circulating cardiometabolic risk factors: triacylglycerol, LDL-C, HDL-C, glucose, insulin, uric acid, C-reactive protein, fibrinogen, and homocysteine. We collected data on 224 healthy postmenopausal women at risk for osteoporosis (45.8–65 y, median BMI 24.5) who consumed placebo or soy isoflavones (80 or 120 mg/d) for 36 months and used longitudinal analysis to examine the contribution of isoflavone treatment, androidal fat mass, other biologic factors, and dietary quality to cardiometabolic outcomes. Except for homocysteine, each cardiometabolic outcome model was significant (overall P-values from ≤.0001 to .0028). Androidal fat mass was typically the strongest covariate in each model. Isoflavone treatment did not influence any of the outcomes. Thus, androidal fat mass, but not isoflavonetreatment, is likely to alter the cardiometabolic profile in healthy postmenopausal women.

Contribution of serum inflammatory markers to changes in bone mineral content and density in postmenopausal women: a 1-year investigation

Bone formation and resorption are influenced by inflammatory processes. We examined the relationships among inflammatory markers and bone mineral content (BMC) and density (BMD) and determined the contribution of inflammatory markers to 1-yr changes in BMC and BMD in healthy postmenopausal women. This analysis included 242 women at baseline from our parent Soy Isoflavones for Reducing Bone Loss project who were randomly assigned to 1 of 3 treatment groups: placebo, 80 mg/d soy isoflavones, or 120 mg/d soy isoflavones. BMD and BMC from the lumbar spine (LS), total proximal femur (hip), and whole body were measured by dual energy X-ray absorptiometry and the 4% distal tibia by peripheral quantitative computed tomography. Serum inflammatory markers (C-reactive protein, interleukin [IL]-1 beta, IL-6, tumor necrosis factor-alpha [TNF-alpha], and white blood cell count [WBC]) were measured at baseline, 6, and 12 mo. Because of attrition or missing values, data analysis at 12 mo includes only 235 women. Significant associations among IL-6, TNF-alpha, and WBC were observed with percent change in LS, hip, and whole body BMC and BMD. Multiple regression analysis indicated that in combination inflammatory markers accounted for 1.1-6.1% of the variance to the observed 12-mo changes in BMC and BMD. Our results suggest that modifying inflammatory markers, even in healthy postmenopausal women, may possibly reduce bone loss.

Bone mineral content of cyclically menstruating female resistance and endurance trained athletes

The bone mineral content (BMC) at four sites on the axial and appendicular skeleton was compared among four groups of young adult (age = 17-38 yr) cyclically menstruating athletes (N = 40) who regularly performed either weightlifting resistance exercise (body builders) or nonresistance endurance exercise (runners, swimmers) and an inactive group of females (N = 18) of about equal age. Forearm BMC was measured using single photon absorptiometry at proximal (shaft) and distal sites on the radius. Dual photon absorptiometry was used to measure BMC at the lumbar vertebrae (L2-4) and femur at the femoral neck, Ward's triangle, and greater trochanter. Fat-free body mass (FFBM) was estimated from densitometry. Body builders had greater BMC than swimmers, collegiate runners, recreational runners, and controls. Mean differences in BMC among runners, swimmers, and controls were not significant (P less than or equal to 0.05). FFBM was correlated significantly with BMC (r = 0.35-0.56) at each site in the combined group of athletes (N = 39), whereas total body weight and BMC were correlated significantly at the distal radius site (r = 0.38) only. The results suggest that weight training may provide a better stimulus for increasing BMC than run and swim training.

Variation in bone mineral content and estimated body fat in young adult females

This study was designed to determine whether variability in bone mineral content (BMC) at the lumbar vertebrae (L2-4), radius shaft (RS), femoral neck, and distal radius can significantly contribute to the variability observed in body density (Db) among 89 females (age = 25.1 +/- 5.3 yr) of varying activity levels and menstrual status. Theoretical differences in Db were calculated at +/- 1 and +/- 2 standard deviations of BMC (SDBMC) for the population as well as for the subgroups: eumenorrheic inactive controls (C), recreational runners (RR), collegiate runners (CR), body builders (BB), swimmers (S), and amenorrheic runners (AR). Multiple regression to predict Db yielded significant coefficients (b) for BMC at L2-4 (b = 0.0190, P less than 0.001) and RS (b = 0.0425, P less than 0.01) when added separately to the sum of four skinfolds (subscapula, abdomen, thigh, calf). The differences in % BFHW at +/- 1 and +/- 2 SDBMC for the sample mean for RSBMC were +/- 1.0% and +/- 2.0%, respectively. Variability in L2-4 contributed differences of +/- 1.3% and +/- 2.6% at +/- 1 and +/- 2 SDBMC. The subgroup % BFHW differences (due to L2-4 and RS combined) ranged from an average overestimation of 1.3% for the AR to an average underestimation of 1.4% for the BB. Estimated mean errors for remaining groups were less than or equal to 0.5%. Individual differences ranged from a 3.3% underestimation (BB) to a 3.0% overestimation (AR).(ABSTRACT TRUNCATED AT 250 WORDS)

Atlanto-axial instability in children with Down syndrome

One hundred fifty-eight patients with Down syndrome underwent roentgenologic examinations of the cervical spine in neutral position, in hyperflexion, and in hyperextension. Fifteen children with Down syndrome were found to have a distance between the joint surfaces of 5 mm and more. The majority of these children were asymptomatic, one child displayed hyperactive deep tendon reflexes and two children were symptomatic and underwent surgery.