A multicenter study evaluation of the ClearLLab 10C panels

Multiparameter flow cytometry plays an important role in the diagnosis, staging, and monitoring of patients with a suspected hematological malignancy. The ClearLLab 10C Panels consist of four reagent panels (B-Lineage Tube, T-Lineage Tube, and 2 Myeloid Lineage Tubes), each consisting of 10 color/10 antibody conjugates utilizing Beckman Coulters proprietary dry format optimized for investigating patients with suspected leukemia or lymphoma. A multicenter study was conducted to evaluate the performance of the ClearLLab 10C Panels for qualitative assessment of normal versus abnormal phenotype in peripheral blood, bone marrow, and lymph node samples with suspected hematological malignancies. ClearLLab 10C was compared to laboratory developed tests (LDTs) and final clinical diagnosis. Four clinical sites were used to enroll patient's spent specimens (n = 453); three laboratories in North America and one in Europe. Of the 453 specimens, 198 had no malignancy and 255 contained an abnormal population. The diagnostic accuracy of the ClearLLab 10C Panels was achieved with sensitivity of 96% and specificity of 95% with respect to patient final clinical diagnosis. The agreement of phenotyping between ClearLLab10C Panels and LDTs was 98%. Any differences noted between ClearLLab 10C and LDT were due to either the presence of populations below the level of detection, the lack of clinical information provided to the evaluators, or marker(s) not present in these panels. Overall, the ClearLLab 10C demonstrated excellent agreement to LDTs and diagnosis. These four reagent panels can be adopted by individual laboratories to assess the presence or absence of malignancy.

Assessment of the AQUIOS flow cytometer - An automated sample preparation system for CD4 lymphocyte PanLeucogating enumeration

Background

Flow cytometry has been the approach of choice for enumerating and documenting CD4-cell decline in HIV monitoring. Beckman Coulter has developed a single platform test for CD4+ T-cell lymphocyte count and percentage using PanLeucogating (PLG) technology on the automated AQUIOS flow cytometer (AQUIOS PLG).

Objectives

This study compared the performance of AQUIOS PLG with the Flowcare PLG method and performed a reference interval for comparison with those previously published.

Methods

The study was conducted between November 2014 and March 2015 at 5 different centres located in Canada; Paris, France; Lyon, France; the United States; and South Africa. Two-hundred and forty samples from HIV-positive adult and paediatric patients were used to compare the performances of AQUIOS PLG and Flowcare PLG on a FC500 flow cytometer (Flowcare PLG) in determining CD4+ absolute count and percentage. A reference interval was determined using 155 samples from healthy, non-HIV adults. Workflow was investigated testing 440 samples over 5 days.

Results

Mean absolute and relative count bias between AQUIOS PLG and Flowcare PLG was −41 cells/µL and −7.8%. Upward and downward misclassification at various CD4 thresholds was ≤ 2.4% and ≤ 11.1%. The 95% reference interval (2.5th – 97.5th) for the CD4+ count was 453–1534 cells/µL and the percentage was 30.5% – 63.4%. The workflow showed an average number of HIV samples tested as 17.5 per hour or 122.5 per 8-hour shift for one technician, including passing quality controls.

Conclusion

The AQUIOS PLG merges desirable aspects from conventional flow cytometer systems (high throughput, precision and accuracy, external quality assessment compatibility) with low technical operating skill requirements for automated, single platform systems.

[Asteroid hyalosis within an epiretinal membrane]

CASE REPORT

In May 2007 an 80-year-old man with a known proliferative diabetic retinopathy presented in our outpatient department with a decrease in visual acuity of his right eye. There was a thick asteroid hyalosis preventing fundus examination. Sonographically, there were vitreoretinal tractions requiring a vitrectomy. During surgery an epipapillary membrane was removed.

RESULTS

Microscopically round amorphous bodies were conspicuous which were slightly basophilic in the H&E stain. The amorphous bodies were strongly positive in the periodic acid-Schiff staining. They were embedded in a fibrovascular stroma and partly surrounded by inflammatory cells with numerous giant cells of foreign body reaction.

CONCLUSION

Asteroid hyalosis is a common degenerative disorder in the vitreous body. The aetiology and the pathogenesis of the asteroid bodies are not yet fully understood. An association of asteroid hyalosis with systemic diseases like diabetes mellitus, arterial hypertension, hyperlidpidaemia and atherosclerotic vasculopathy is postulated. Normally, therapy for an asymptomatic asteroid hyalosis is not necessary. The tractive proliferative diabetic retinopathy in our patient did require surgery. The incorporation of hyaloid bodies into an epiretinal membrane with the induction of a foreign body reaction is unusual.

[Herpes keratitis after corneal trauma--a possible occupational disease?]

BACKGROUND

Herpes simplex virus (HSV) keratitis is among the most common causes of infectious corneal disease and encompasses epithelial, stromal and endothelial disease processes. Different trigger factors are commonly thought to be associated with recurrences of HSV keratitis but, in spite of its high prevalence, the exact mechanisms for the recurring nature of HSV keratitis are unclear. Ophthalmologists therefore face difficulties when asked to assess the relation between ocular trauma and subsequent herpetic eye disease.

CASE REPORT

At the age of 21, a man developed stromal herpetic keratitis of his right eye. Ten years later, he experienced a superficial corneal injury of the same eye with a metal foreign body during work. Subsequently, severe stromal keratitis with multiple recurrences developed. Due to progressive endothelial decompensation, a perforating keratoplasty was performed at the age of 51. Six years thereafter, re-keratoplasty became necessary because of a fungal keratitis of the transplant. The patient was convinced that the initial occupational corneal injury was the cause of the following recurrences of HSV keratitis and therefore was responsible for the resulting reduction of visual acuity. He thus filed an action for receiving an invalidity pension.

RESULTS

The different possible pathophysiological situations at the time of induction of a traumatic herpetic keratitis are presented and discussed. General guidelines for the assessment of traumatic herpetic keratitis are suggested.

CONCLUSIONS

Patients who have suffered from one or more previous episodes of HSV keratitis are at a high risk for recurrences. In the depicted case, stromal keratitis had already occurred once before the trauma. The recurrences of herpetic keratitis following the injury therefore could not be attributed to the trauma with sufficient probability.

Effect of dacarbazine (DTIC) on cultures from malignant melanoma of the choroid: an immunohistochemical and electron microscopic study

INTRODUCTION

Dacarbazine (DTIC) is a very effective chemotherapeutic agent used in the treatment of cutaneous melanoma; it also could have a potential therapeutic value as an antimetastatic agent in the treatment of choroidal melanoma.

OBJECTIVE

To study the HMB-45 and S100 protein expression in choroidal melanoma cultures with and without DTIC, and compare the immunohistochemical and electron microscopic changes in both groups.

METHODS

Five- and seven-day cultures of choroidal melanoma (n = 21) were cultivated in diffusion chambers. The cultures were divided in two groups: I group (control group)--the cells were grown in 199-medium; II group--the cells were in 199-medium supplemented with 0.03 mg/ml of DTIC. Immunohistochemical studies were performed with paraffin-embedded material of the cultures by the avidin-biotin-alkaline phosphatase technique. Araldit-embedded material was studied by electron microscopy.

RESULTS

The expression of HMB-45 and S100 protein in the cultures with DTIC ranged from slightly positive to negative. The tumor cells were severely damaged. Electron microscopy in this group showed presence only of cellular fragments. In the DTIC-free group the HMB-45 and S100 expressions were strongly positive. There were no electron microscopic evidence of cellular death.

CONCLUSION

DTIC suppresses the growth of choroidal melanoma in vitro. These results indicate that further studies are warranted to elucidate the effect of DTIC in vivo.