Point-of-Care Platform Blood Biomarker Testing of Glial Fibrillary Acidic Protein versus S100 Calcium-Binding Protein B for Prediction of Traumatic Brain Injuries: A Transforming Research and Clinical Knowledge in Traumatic Brain Injury Study
Glial fibrillary acidic protein (GFAP) is cleared by the Food and Drug Administration (FDA) to determine need for head computed tomography (CT) within 12 h after mild traumatic brain injury (TBI) (Glasgow Coma Score [GCS] 13–15); S100 calcium-binding protein B (S100B) serves this function in Europe. This phase 1 biomarker cohort analysis of the multi-center, observational Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study compares GFAP's diagnostic performance, measured on a rapid point-of-care platform, against protein S100B to predict intracranial abnormalities on CT within 24 h post-injury across the spectrum of TBI (GCS 3–15). Head CT scan performed in TBI subjects and blood was collected for all consenting subjects presenting to 18 United States level 1 trauma centers. Plasma was analyzed on a point-of-care device prototype assay for GFAP and serum was analyzed for S100B. In 1359 patients with TBI (GCS 3–15), mean (standard deviation [SD]) age = 40.1 (17.0) years; 68% were male. Plasma GFAP levels were significantly higher in CT+ TBI subjects (median = 1358 pg/mL, interquartile range [IQR]: 472–3803) than in CT- TBI subjects (median = 116 pg/mL, IQR: 26–397) or orthopedic trauma controls ( n = 122; median = 13 pg/mL, IQR: 7–20), p < 0.001. Serum S100B levels were likewise higher in CT+ TBI subjects (median = 0.17 μg/L, IQR: 0.09–0.38) than in CT- TBI subjects (median = 0.10 μg/L, IQR: 0.06–0.18), p < 0.001. Receiver operating characteristic curves were generated for prediction of intracranial injury on admission CT scan; area under the curve (AUC) for GFAP was significantly higher than for S100B in the same cohort (GFAP AUC – 0.85, 95% confidence interval [CI] 0.83–0.87; S100B AUC – 0.67, 95% CI 0.64-0.70; p < 0.001). GFAP, measured on a point-of-care platform prototype assay, has high discriminative ability to predict intracranial abnormalities on CT scan in patients with TBI across the full injury spectrum of GCS 3–15 through 24 h post-injury. GFAP substantially outperforms S100B.
Dynamic Phenotypes of Degenerative Myxomatous Mitral Valve Disease
Background— Fibro-elastic deficiency (FED) and diffuse myxomatous degeneration (DMD) are phenotypes of degenerative mitral valve disease defined morphologically. Whether physiological differences in annular and valvular dynamics exist between these phenotypes remains unknown. Methods and Results— We performed triple quantitation of cardiac remodeling and of mitral regurgitation severity and of annular and valvular dimensions by real-time 3-dimensional-transesophageal-echocardiography. Forty-nine patients with degenerative mitral valve disease classified as FED (n=31) and DMD (n=18) by surgical observation showed no difference in age (65±10 versus 59±13; P =0.5), body surface area (2.0±0.2 versus 2.0±0.2 m 2 ; P =0.5), left ventricular and atrial dimensions (all P >0.55), and mitral regurgitation regurgitant orifice ( P =0.62). On average, annular dimensions were larger in DMD versus FED, but height was similar resulting in lower saddle shape. Dynamically, annular DMD versus FED display poorer contraction and saddle-shape accentuation in early systole and abnormal enlargement, particularly intercommissural, in late-systole (all P <0.05). Valvular dynamics showed stable valvular area in systole in FED versus considerable systolic increased area in DMD ( P <0.001). Prolapse height and volume increased little throughout systole in FED versus marked increase in DMD ( P <0.001). Conclusions— Our novel observations show that FED and DMD, although both labeled myxomatous, display considerable physiological phenotypic differences. In DMD, the annular increased size and profoundly abnormal dynamics demonstrate DMD-specific annular degeneration compared with the enlarged but relatively normal FED annulus. DMD does not incur more severe mitral regurgitation, despite larger prolapse and valve redundancy, underscoring potential compensatory role of tissue redundancy of DMD (or aggravating role of tissue paucity of FED) on mitral regurgitation severity.
Cleft-like indentations in myxomatous mitral valves by three-dimensional echocardiographic imaging
Objectives Cleft-like indentations (CLI) are deep separations between scallops of the mitral posterior leaflet observed in myxomatous mitral valve disease (MMVD), but their diagnosis, mechanisms and implications are unknown. Using 3D transoesophageal echocardiography (3DTOC), we aimed at assessing diagnostic accuracy and defining mechanisms of CLI in patients undergoing surgery for MMVD. Methods 3DTOC of mitral valve was acquired in 49 patients with MMVD and severe regurgitation prior to valve repair. Qualitative review compared 3DTOC diagnosis of CLI with surgical inspection. Mitral, annular and leaflet dimensions were quantified with dedicated software and compared between those with and without CLI. Results Diagnosis of CLI was made by 3DTOC in 17 (35%) while none was identified by 2D and was confirmed in 15 (88%) by surgical inspection. Mechanistically, LV diameters and mitral regurgitant volume (RVol) were similar with and without CLI (p>0.49). Conversely, mitral annulus was smaller with CLI (anteroposterior diameter 42.2±7.1 vs 47.0±7.5 mm, p=0.04; circumference 133±16 vs 148±19 mm, p=0.009; area 1289±326 vs 1619±427 mm2, p=0.008). Prolapse volume tended to be smaller with CLI (1.9±1.2 vs 4.0±4.3 mL, p=0.06) involving single posterior scallop at surgery (82% vs 44%, p=0.007) with smaller 3DTOC leaflet area (1574±409 vs 2019±652 mm2, p=0.01). During valve repair, surgical closure of all surgically diagnosed CLI was required. Conclusions Posterior leaflet CLI are frequent in MMVD, are identified by 3DTOC with high accuracy and require closure during valve repair. CLI are mechanistically not related to excess annular enlargement or excess prolapse. Conversely, CLI occur in the context of single scallop prolapse with tissue paucity causing excess separation of scallops. These 3DTOC data enhance diagnostic and mechanistic comprehension of the diversity of MMVD phenotypical presentation.
Relative value of ZAP-70, CD38, and immunoglobulin mutation status in predicting aggressive disease in chronic lymphocytic leukemia
AbstractLeukemia-cell expression of ZAP-70, CD38, or unmutated immunoglobulin heavy chain variable region genes (U-IGHV) each is associated with aggressive disease in patients with chronic lymphocytic leukemia (CLL). To assess the relative strength of each marker, we defined thresholds for designating a case as positive for CD38 or ZAP-70 in a test cohort of 307 patients and used these data-defined criteria to stratify patients in an independent cohort of 705 patients. Multivariable analysis revealed that ZAP-70 was the strongest risk factor. Knowledge of the IGHV mutation status or CD38 did not improve our ability to predict the time to first treatment except for ZAP-70–negative cases, which could be segregated into 2 groups of intermediate-risk or low-risk disease based on whether they expressed unmutated or mutated IGHV. ZAP-70 maintained its high relative prognostic value for the subset of patients with early-stage, asymptomatic disease, including patients evaluated within 1 year of diagnosis. Although it is premature to recommend therapy based on these risk factors, patients with ZAP-70–positive CLL cells should be monitored closely for disease progression as they have a median time from diagnosis to requiring initial therapy by standard criteria of approximately 3 years.
Use of IGHV3–21 in chronic lymphocytic leukemia is associated with high-risk disease and reflects antigen-driven, post–germinal center leukemogenic selection
AbstractWe examined the chronic lymphocytic leukemia (CLL) cells of 2457 patients evaluated by the CLL Research Consortium (CRC) and found that 63 (2.6%) expressed immunoglobulin (Ig) encoded by the Ig heavy-chain-variable-region gene (IGHV), IGHV3-21. We identified the amino acid sequence DANGMDV (motif-1) or DPSFYSSSWTLFDY (motif-2) in the Ig heavy-chain (IgH) third complementarity-determining region (HCDR3) of IgH, respectively, used by 25 or 3 cases. The IgH with HCDR3 motif-1 or motif-2, respectively, was paired with Ig light chains (IgL) encoded by IGLV3-21 or IGKV3-20, suggesting that these Ig had been selected for binding to conventional antigen(s). Cases that had HCDR3 motif-1 had a median time from diagnosis to initial therapy comparable with that of cases without a defined HCDR3 motif, as did cases that used mutated IGHV3-21 (n = 27) versus unmutated IGHV3-21 (n = 30). Of 7 examined cases that used Ig encoded by IGHV3-21/IGLV3-21, we found that 5 had a functionally rearranged IGKV allele that apparently had incurred antigendriven somatic mutations and subsequent rearrangement with KDE. This study reveals that CLL cells expressing IGHV3-21/IGLV3-21 most likely were derived from B cells that had experienced somatic mutation and germinal-center maturation in an apparent antigen-driven immune response before undergoing Ig-receptor editing and after germinal-center leukemogenic selection.