A more efficient enzyme-linked immunosorbent assay for measurement of alpha-synuclein in cerebrospinal fluid.

We describe a modification of a previously described assay for the quantification of alpha-synuclein in naive cerebrospinal fluid, which allows for a more efficient quantification of alpha-synuclein. Detection limit of the assay is 3.8 ng/ml and the assay is linear until 300 ng/ml. Inter-assay and intra-assay coefficients of variation are below 15% in a wide range of concentrations. Mean recovery of the assay is 94%. The 95% upper limit of the reference range (p95) in a group of neurological controls above the age of 45 years is 62 ng/ml. This assay can be routinely applied for quantification of alpha-synuclein in cerebrospinal fluid, but not in serum, and this may serve as a possible biomarker for alpha-synucleinopathies such as Parkinson's disease and multiple system atrophy.

Diagnostic accuracy of ELISA and xMAP technology for analysis of amyloid beta(42) and tau proteins.

BACKGROUND: Cerebrospinal fluid (CSF) concentrations of amyloid beta(42) (Abeta(42)) peptides and tau proteins may serve as biomarkers for Alzheimer disease (AD). Recently, the xMAP technology has been introduced as an alternative to ELISA for measurement of these markers. METHODS: We used xMAP assays and ELISA to analyze CSF concentrations of Abeta(42), total tau (t-tau), and tau phosphorylated at threonine 181 (p-tau(181)) in samples from 69 patients with Alzheimer disease, 26 patients with vascular dementia, and 55 controls without neurological disorders. RESULTS: High CV values (>28%) for the ratio of xMAP:ELISA were observed for each biomarker, indicating that a constant correction factor cannot be applied to recalculate xMAP results into ELISA results. When a combination of CSF markers was used, the sensitivity, specificity, and area under the ROC curves for xMAP assays and ELISAs were not significantly different in differentiating AD patients from vascular dementia patients and controls. CONCLUSIONS: A constant conversion factor cannot be used successfully to recalculate results obtained with xMAP assays to those from the ELISAs. With the use of analysis of a combination of Abeta(42), t-tau, and p-tau in CSF, however, differentiation of clinical groups is equivalent when either xMAP technology or conventional ELISA is used.

Rapid immunoassay for the determination of glial fibrillary acidic protein (GFAP) in serum.

BACKGROUND: This study was aimed to develop a sensitive and rapid assay for the determination of glial fibrillary acidic protein (GFAP) in serum and to evaluate the clinical applicability in serum samples from patients with acute stroke. METHODS: The two-site chemiluminometric immunoassay, intended to use in a near-patient setting with a single incubation step (20 min), was used to measure serum samples from healthy blood donors and from patients with brain injury and correlated to serum S100B levels. RESULTS: The GFAP assay covered a concentration range up to 18 microg/L with an analytical sensitivity of 0.014 microg/L. The intra-assay precision was 3.5% at 1.55 microg/L (n=20) and 4.1% at 0.39 microg/L (n=20). The inter-assay precision was 3.8% at 9.1 microg/L (n=10) and 10.3 % at 0.21 microg/L (n=9). Normal controls (n=46) showed non-detectable GFAP with a 99% upper limit of <0.04 microg/L. GFAP values were associated with progression and severity of the illness in acute stroke patients. CONCLUSIONS: We have developed an improved assay for the measurement of GFAP levels in serum. Serum GFAP is a potential marker for prognosis and outcome in patients with central nervous system disorders.

Measurement of glial fibrillary acidic protein in blood: an analytical method.

BACKGROUND: In the present study, a new assay for the measurement of glial fibrillary acidic protein (GFAP) in human blood is described. The aim of the study was to present the characteristics of a new GFAP assay for blood analysis. METHODS: The method, a newly developed enzyme-linked immunosorbent assay (ELISA), was validated using blood samples from healthy blood donors and from patients with severe traumatic brain injury (TBI). RESULTS: 22 out of 72 healthy blood donors had a detectable GFAP level. The reference values (percentiles) are as follows: P50=0.15 microg/l and P95=0.49 microg/l; range 0.15-0.76 microg/l. CONCLUSIONS: GFAP in blood might be a promising new marker for astrocyte involvement after acute brain damage.

Giant cell tumor of the larynx: a clinicopathologic series of eight cases and a review of the literature.

True giant cell tumors of the larynx (GCTL) are quite rare, and only individual case reports are documented in the literature. Eight cases of GCTL were identified in the Otorhinolaryngic Pathology Tumor Registry between 1966 and 2000. There were 2 women and 6 men, ages 26 to 62 years (mean, 44.5 yrs). Patients presented with a palpable neck mass (n = 5), airway obstruction (n = 3), hoarseness (n = 3), and dysphagia (n = 2). All tumors involved the thyroid cartilage, a few with local extension. The mean tumor size was 4.1 cm. Histologically, the tumors showed no connection to the surface epithelium and arose in sites of ossification. The tumors had an expansile, infiltrative growth and consisted of numerous multinucleated osteoclast-like giant cells within a cellular stroma composed of plump, oval mononuclear cells. Of interest was that the nuclei of the giant cells were similar to the nuclei of the stromal cells. Treatment included biopsy only with adjuvant therapy (n = 2), local resection (n = 3), and total laryngectomy (n = 3). Follow-up showed 5 patients were alive without evidence of disease (mean follow-up, 6.9 yrs); 2 died of unrelated causes (mean survival, 22.2 yrs). No patients developed recurrences. GCTL are rare tumors that can cause significant airway obstruction. Complete surgical resection yields an excellent outcome without adjuvant therapy.

Corticomedullary mixed tumor of the adrenal gland.

Corticomedullary mixed tumors of the adrenal gland are quite rare, with only five well-documented cases reported in the literature.(1-4) Herein, we report the light microscopic and immunohistochemical features of two cases of this rare tumor. Patient 1 is a 34-year-old woman who presented with hypertension, hair loss, and amenorrhea of 1-year duration. Patient 2 is a 52-year-old woman who presented with flank pain and what appeared to be a renal mass on arteriogram with no history of hypertension, Cushing's syndrome, or other endocrine abnormalities. At surgery, the tumor was noted to arise from the adrenal gland rather than the kidney and adrenalectomy was performed. In both cases, the surgically resected specimens consisted of a well-circumscribed, single adrenal mass surrounded by a rim of uninvolved adrenal cortical tissue. The tumors were composed of adrenal cortical cells intimately admixed with pheochromocytes. Immunohistochemical studies highlighted these two cellular components. The pheochromocytes were strongly reactive with chromogranin and the sustentacular cells with S-100 protein, whereas the adrenal cortical cells reacted specifically with inhibin. Thus, we report two additional cases of mixed corticomedullary tumor of the adrenal gland. Ann Diagn Pathol 5:304-308, 2001. This is a US government work. There are no restrictions on its use.

Laryngeal angiosarcoma: a clinicopathologic study of five cases with a review of the literature.

OBJECTIVE: Primary laryngeal angiosarcoma (LA) is rare without a reported series evaluating these tumors. STUDY DESIGN/METHODS: Five patients with LA were retrospectively retrieved from the Otorhinolaryngic Registry of the Armed Forces Institute of Pathology. RESULTS: Three men and 2 women, aged 29 to 71 years, presented with hoarseness (n = 4) and hemoptysis (n = 1). Two patients had previous neck radiation. The tumors involved the supraglottis (n = 4) with a mean size of 3.1 cm. Histologically, all tumors had anastomosing vascular channels lined by remarkably atypical endothelial cells protruding into the lumen, frequent atypical mitotic figures, and hemorrhage. All cases tested (n = 4) demonstrated immunoreactivity with antibodies to Factor VIII-RA and CD34. All patients had surgery followed by postoperative radiation (n = 3 patients). Three patients died with disease (mean, 17 mo), whereas one patient is alive with no evidence of disease at 18 years. CONCLUSIONS: LA is a rare tumor, frequently associated with previous radiation, usually involving the supraglottis with characteristic histomorphologic and immunophenotypic features. LA has a poor prognosis, making appropriate separation from other conditions important.

A clinicopathologic study of minimally invasive follicular carcinoma of the thyroid gland with a review of the English literature.

BACKGROUND: The criteria for minimally invasive (low grade) follicular carcinoma of the thyroid (MI) remain controversial, often resulting in unnecessary treatment. METHODS: The records of 130 patients with minimally invasive (MI) follicular thyroid carcinoma were retrieved from the files of the Endocrine Tumor Registry of the Armed Forces Institute of Pathology. RESULTS: Ninety-five patients were confirmed to have MI based on the authors' criteria of small-to-medium vessel invasion, capsular invasion of up to full thickness, no parenchymal tumor extension, and no tumor necrosis (patients with oxyphilic tumors were excluded). The remaining 35 patients had tumors that were reclassified as "not low grade" based on large vessel invasion, extension into parenchyma, and tumor necrosis (oxyphilic cases excluded). The MI patients included 67 women and 28 men, ages 20-95 years (average, 42.0 years). Nearly all patients presented with a thyroid mass (n = 90 patients). The mean tumor size was 2.8 cm. Histologic features examined for tumor classification included cellularity, capsule nature, capsular invasion, vascular invasion, extension into parenchyma, cytoplasmic oxyphilia, mitotic activity, and necrosis. All patients were treated with surgical excision. Adjuvant radioactive iodine therapy was performed in 24 patients. Five patients developed recurrent disease: four were alive or had died without evidence of disease after additional treatment (mean, 18.1 years), and one patient died with disease (MI tumor) at 15.1 years. All of the remaining patients were disease free (mean follow-up, 16.5 years). CONCLUSIONS: There are reproducible histologic criteria to diagnose patients with MI follicular carcinoma. The overall excellent long term prognosis and a good patient outcome suggests that no additional surgery is necessary.

Basaloid squamous cell carcinoma of the sinonasal tract.

BACKGROUND: Basaloid squamous cell carcinoma (BSCC) is a high grade, aggressive variant of squamous cell carcinoma with a predilection for the larynx, hypopharynx, tonsils, and base of the tongue. To the authors' knowledge, BSCC originating in the nasal cavity and paranasal sinuses rarely has been reported. METHODS: Fourteen cases of BSCC involving the nasal cavity and paranasal sinuses were identified in the files of the Otolaryngic-Head and Neck Pathology Tumor Registry of the Armed Forces Institute of Pathology from 1975-1997. Clinical records and follow-up were available in all cases. Paraffin blocks were available for histochemical and immunohistochemical studies in all cases. RESULTS: There were 7 females and 7 males, ages 32-86 years (median, 66.5 years; mean, 62 years). The patients presented primarily with a mass lesion and unilateral nasal obstruction. In nine patients the tumor was confined to the nasal cavity. In three patients the tumor involved the sinuses alone and in two patients the tumor involved the nasal cavity and paranasal sinuses. Histologically, the tumors were widely invasive with a variety of growth patterns, including lobular, solid, trabecular, cribriform, and fascicular. The neoplastic infiltrate included predominantly pleomorphic, basaloid-appearing cells with hyperchromatic nuclei, inconspicuous to prominent nucleoli, and a variable amount of eosinophilic to clear-appearing cytoplasm. Mitotic figures, including atypical forms, were readily apparent as was necrosis (individual cell and comedo-type). Foci of squamous differentiation were limited in extent but were found in all cases and included squamous whorls, individual cell keratinization, and intercellular bridges. Intraepithelial dysplasia, carcinoma in situ, or invasive squamous carcinoma was present in all cases. Other histologic features included intercellular stromal hyalinization and peripheral nuclear palisading. In two cases, neural-type rosettes were found. Immunoreactivity for a variety of epithelial markers including cytokeratin (AE1/AE3/LP34), CAM 5.2, 34betaE12, CK7, and epithelial membrane antigen was present in all cases. Variable reactivity was present with vimentin, actins (smooth muscle and muscle specific), neuron specific enolase, S-100 protein, glial fibrillary acidic protein, CK20, carcinoembryonic antigen, Leu7, and Ewing's marker. Chromogranin, synaptophysin, neurofibrillary protein, leukocyte common antigen, HMB-45, desmin, and Epstein-Barr virus latent membrane protein were absent. Surgical resection was the treatment of choice. Eight patients had recurrent or persistent tumor and metastatic disease occurred in five patients. At last follow-up, 7 patients (50%) had died of disease with a median survival of 12 months from the time of diagnosis and 3 patients were alive with disease over periods ranging from 8 months-5 years. Of the 4 remaining patients, 2 were alive without disease at 1 month and 5 years, respectively, 1 patient was lost to follow-up with no evidence of tumor at 3 years, and 1 patient had died of unrelated causes with no evidence of disease. CONCLUSIONS: Sinonasal BSCC is a histologically distinct variant of squamous cell carcinoma with pathologic features and aggressive biologic behavior similar to BSCC localized to more common mucosal sites of the upper aerodigestive tract.