Miller, Dylan V.

Objective To describe the treatment and outcomes of patients with primary central nervous system (CNS) vasculitis. Methods We retrospectively studied a cohort of 163 consecutive patients with primary CNS vasculitis who were seen at the Mayo Clinic over a 29‐year period. We analyzed treatments, treatment responses, and factors predictive of outcomes. Results A favorable response was observed in 85% of patients treated with prednisone alone and in 80% of patients treated with prednisone and cyclophosphamide. Relapses were observed in 27% of patients, and 25% of patients had discontinued therapy by the time of the last followup visit. Treatment with prednisone alone was associated with more frequent relapses (odds ratio [OR] 2.90), while large vessel involvement (OR 6.14) and cerebral infarcts at the time of diagnosis (OR 3.32) were associated with a poor response to treatment. Prominent gadolinium‐enhanced cerebral lesions or meninges were linked with continued treatment at the last followup encounter (OR 2.28). Higher disability scores at the last followup visit were associated with increasing age at the time of diagnosis (OR 1.44) and cerebral infarctions (OR 3.74), while lower disability scores were associated with gadolinium‐enhanced cerebral lesions or meninges (OR 0.35) and cerebral amyloid angiopathy (OR 0.24). Increased mortality was associated with increasing age at diagnosis (hazard ratio [HR] 1.39), diagnosis by angiography (HR 3.28), cerebral infarction (HR 4.44), and large vessel involvement (HR 4.98), while reduced mortality was associated with gadolinium‐enhanced cerebral lesions or meninges (HR 0.20). Conclusion The majority of patients with primary CNS vasculitis responded to treatment. Recognition of findings at diagnosis that predict the course or outcome may aid in decision‐making regarding therapy.

Background— Mutations in myofilament proteins, most commonly MYBPC3 -encoded myosin-binding protein C and MYH7 -encoded β-myosin heavy chain, can cause hypertrophic cardiomyopathy (HCM). Despite significant advances in structure-function relationships pertaining to the cardiac sarcomere, there is limited knowledge of how a mutation leads to clinical HCM. We, therefore, set out to study expression and localization of myofilament proteins in left ventricular tissue of patients with HCM. Methods and Results— Frozen surgical myectomy specimens from 47 patients with HCM were examined and genotyped for mutations involving 8 myofilament-encoding genes. Myofilament protein levels were quantified by Western blotting with localization graded from immunohistochemical staining of tissue sections. Overall, 25 of 47 (53%) patients had myofilament-HCM, including 12 with MYBPC3-HCM and 9 with MYH7-HCM. As compared with healthy heart tissue, levels of myofilament proteins were increased in patients manifesting a mutation in either gene. Patients with a frameshift mutation predicted to truncate MYBPC3 exhibited marked disturbances in protein localization as compared with missense mutations in either MYBPC3 or MYH7 . Conclusions— In this first expression study in human HCM tissue, increased myofilament protein levels in patients with either MYBPC3 - or MYH7- mediated HCM suggest a poison peptide mechanism. Specifically, the mechanism of dysfunction may vary according to the genetic subgroup suggested by a distinctly abnormal distribution of myofilament proteins in patients manifesting a truncation mutation in MYBPC3 .

Cardiac fibromas are the 2nd most common benign cardiac tumor occurring in children and bear a striking morphologic resemblance to soft tissue or desmoid fibromatosis. Since activating mutations in beta-catenin are common in desmoid fibromatosis as well as other spindle cell proliferations, the aim of our study was to determine if such mutations could be identified in cardiac fibroma. Nine cardiac fibromas from patients with surgical resection were examined for beta-catenin mutations by immunoperoxidase staining for beta-catenin protein and DNA sequencing of a region in exon 3 of the beta-catenin gene, where relatively conserved mutations have been described in desmoid fibromatosis. The mean age of the patients was 7.6 years (range: 10 weeks to 27 years), and 6 of the patients were male. No nuclear staining for beta-catenin was seen in the fibroma cells by immunoperoxidase methods. The beta-catenin exon 3 sequence data showed no mutations in any of the 9 tumors. We conclude that despite their morphologic similarity, cardiac fibroma and desmoid fibromatosis do not share this common molecular pathway of neoplastic growth.

Background— Atrioventricular (AV) nodal ablation for management of atrial fibrillation (AF) is irreversible and requires permanent pacemaker implantation. We hypothesized that as an alternative, implantation of autologous fibroblasts in the perinodal region would focally modify AV nodal conduction and that this modulation would be enhanced by pretreatment with transforming growth factor-β1 (TGF-β1), a stimulant of fibroblasts. Methods and Results— Skin biopsies were taken from 12 mongrel dogs, and derived fibroblasts were dissociated and grown in culture for 2 weeks. Multiple injections (0.25 mL) were made through an 8F NOGA catheter along the fast/slow AV nodal pathways as guided by an electroanatomic mapping system. Seven dogs received fibroblasts alone (1×10 6 cells/mL), 7 dogs received TGF-β1 (5 μg), 4 dogs received fibroblasts and TGF-β1 (1×10 6 cells/mL+5 μg), and 4 dogs received saline only. AV node function was assessed at baseline and after 4 weeks. Saline (80 mL) with assigned therapy (0.25 mL per injection) was injected into the peri-AV nodal region in each dog. At baseline, the AH interval (66±3 ms) and the average RR interval (331±17 ms) in pacing-induced AF were similar in each cohort. The increase in AH interval in normal sinus rhythm was longer after fibroblast (23±4 versus 5±5 ms; P =0.05) and fibroblast plus TGF-β1 (50±5 versus 5±5 ms; P <0.001) injections than with saline alone, with similar findings during high right atrium and distal coronary sinus pacing. The AH interval was not significantly increased after TGF-β1 injections. The AH interval was significantly longer after fibroblast plus TGF-β1 injections than with either therapy (TGF-β1 or fibroblasts) alone. The RR interval during AF was increased in dogs that received fibroblasts alone (110±36 versus −41±34 ms) and to a greater extent with the addition of TGF-β1 (294±108 versus −41±34 ms). No AV block was seen in any cohort at 4 weeks. Labeled fibroblasts that expressed vimentin were identified in all dogs that received cell injections at 4 weeks. Conclusions— AV nodal modification can be achieved with injected fibroblasts without the creation of AV block. The effect on AV node conduction is substantially enhanced by pretreatment of fibroblasts with TGF-β1. These data have therapeutic potential for the management of rapid ventricular rate during AF without pacemaker implantation.

Rhabdomyosarcomas (RMS) arising at different anatomic sites have distinct clinicopathologic features that affect prognosis and outcome. RMS arising in the extremities generally have a worse prognosis. Case reports and anecdotal experience suggests the possibility that RMS of the hand or foot (RMSHF) may behave even more aggressively than RMS elsewhere in the extremities. This study describes clinicopathologic features and outcome of RMSHF. Charts and pathologic material from RMSHF cases from institutional files over a 32-year interval were reviewed. Additional cases from published reports and series over a 42-year interval were identified by a MEDLINE search. Pertinent clinicopathologic features for each case were compiled. Survival analysis and other data from these patients were compared with previously reported statistics in the literature for RMS at other anatomic sites, including elsewhere in the extremities. Six patients from the institutional files and 46 from published reports were identified. A number of adverse prognostic indicators were observed in the majority of these patients including alveolar morphology (86%) and distant metastasis at presentation (63%). Despite the aggressive nature of these tumors, the majority were smaller than 5 cm (61%). A propensity was observed for metastases to unusual sites such as breast, ovary, testis, pancreas, and kidney. The median survival was 19 months, and the 5-year survival was 27%. While these may reflect a constellation of findings related to site, it is also possible that alveolar histology is the main influence. RMSHF can present as a very small primary tumor with clinically evident or occult metastatic disease. Whether this reflects the location, the predominantly alveolar histologic type, or a molecular genetic subtype will require further analysis. Patients presenting with RMSHF should be thoroughly evaluated for occult metastases at the time of diagnosis and followed closely throughout treatment for subsequent involvement of unusual sites.