A Prospective Study to Evaluate a Diagnostic Algorithm for the Use of Fluid Lymphocyte Subset Analysis in Undiagnosed Unilateral Pleural Effusions.

BACKGROUND: Haematological malignancy is an important cause of pleural effusion. Pleural effusions secondary to haematological malignancy are usually lymphocyte predominant. However, several other conditions such as carcinoma, tuberculosis, and chronic heart failure also cause lymphocytic effusions. Lymphocyte subset (LS) analysis may be a useful test to identify haematological malignancy in patients with lymphocytic effusions. However, research into their utility in pleural effusion diagnostic algorithms has not yet been published. OBJECTIVES: We aimed to determine the clinical utility of pleural fluid LS analysis and whether it can be applied to a diagnostic algorithm to identify effusions secondary to haematological malignancy. The secondary aim was to evaluate the diagnostic value of pleural fluid differential cell count. METHODS: Consecutive consenting patients presenting to our pleural service between 2008 and 2013 underwent thoracentesis and differential cell count analysis. We proposed an algorithm which selected patients with lymphocytic effusions (>50%) to have further fluid sent for LS analysis. Two independent consultants agreed on the cause of the original effusion after a 12-month follow-up period. RESULTS: A total of 60 patients had samples sent for LS analysis. LS analysis had an 80% sensitivity (8/10) and a 100% specificity for the diagnosis of haematological malignancy. The positive and negative predictive values were 100 and 96.1%, respectively. Overall 344 differential cell counts were analysed; 16% of pleural effusions with a malignant aetiology were neutrophilic or eosinophilic at presentation. A higher neutrophil and eosinophil count was associated with benign diagnoses, whereas a higher lymphocyte count was associated with malignant diagnoses. CONCLUSIONS: LS analysis may identify haematological malignancy in a specific cohort of patients with undiagnosed pleural effusions. A pleural fluid differential cell count provides useful additional information to streamline patient pathway decisions.

Reduced cellularity of bone marrow in multiple sclerosis with decreased MSC expansion potential and premature ageing in vitro.

BACKGROUND: Autologous bone-marrow-derived cells are currently employed in clinical studies of cell-based therapy in multiple sclerosis (MS) although the bone marrow microenvironment and marrow-derived cells isolated from patients with MS have not been extensively characterised. OBJECTIVES: To examine the bone marrow microenvironment and assess the proliferative potential of multipotent mesenchymal stromal cells (MSCs) in progressive MS. METHODS: Comparative phenotypic analysis of bone marrow and marrow-derived MSCs isolated from patients with progressive MS and control subjects was undertaken. RESULTS: In MS marrow, there was an interstitial infiltrate of inflammatory cells with lymphoid (predominantly T-cell) nodules although total cellularity was reduced. Controlling for age, MSCs isolated from patients with MS had reduced in vitro expansion potential as determined by population doubling time, colony-forming unit assay, and expression of ß-galactosidase. MS MSCs expressed reduced levels of Stro-1 and displayed accelerated shortening of telomere terminal restriction fragments (TRF) in vitro. CONCLUSION: Our results are consistent with reduced proliferative capacity and ex vivo premature ageing of bone-marrow-derived cells, particularly MSCs, in MS. They have significant implication for MSC-based therapies for MS and suggest that accelerated cellular ageing and senescence may contribute to the pathophysiology of progressive MS.

Flow cytometry in clinical pathology.

Flow cytometry has had an impact upon all areas of clinical pathology and now, in the 21st century, it is truly coming of age. This study reviews the application of flow cytometry within clinical pathology with an emphasis upon haematology and immunology. The basic principles of flow cytometry are discussed, including the principles and considerations of the flow-cell and hydrodynamic focusing, detector layout and function, use of fluorochromes and multicolour flow cytometry (spectral overlap and colour compensation), alongside the strategies available for sample preparation, data acquisition and analysis, reporting of results, internal quality control, external quality assessment and flow sorting. The practice of flow cytometry is discussed, including the principles and pitfalls associated with leukocyte immunophenotyping for leukaemia and lymphoma diagnosis, immune deficiency, predicting and monitoring response to monoclonal antibody therapy, rare event detection and screening for genetic disease. Each section is illustrated with a case study. Future directions are also discussed.

Immunoglobulin E deficiency: a forgotten clue pointing to possible immunodeficiency?

BACKGROUND: Patients with primary antibody deficiency often have delayed diagnosis. Very low IgE, found during investigations for allergy, may be a marker for other immunodeficiency. METHODS: We introduced a new laboratory policy of testing cases with very low IgE levels for possible linked antibody deficiency. The data represent an audit of routine results collected over two years. RESULTS: Very low IgE (≤2 IU/mL) was identified in 85/2622 (3.2%) routine patient samples. Two children and four adult patients were found to have one or more classes of immunoglobulin below the reference range for age. In 2/6, the initiative of the laboratory led to a new unsuspected diagnosis of antibody immunodeficiency. CONCLUSIONS: Common variable immunodeficiency continues to be overlooked as a primary cause of lung disease in adults. Very low serum IgE should trigger appropriate investigation (immunoglobulin quantification and serum electrophoresis).

Th1 and Th2 subsets in orthopaedic surgery by single-cell cytokine analysis.

Significant immunosuppression can occur following allogeneic blood transfusion or surgery. Cytokine stimulation controls immune responses and determines their type and intensity. Infusion of autologous or allogeneic blood provides elements, including cytokines, which may result in transfusion-associated immunomodulation. This study investigates to what extent autologous/cell salvage transfusions affect levels of intracellular cytokines interferon-gamma and interleukin-4, and if this indicates a shift in the T-helper 1/T-helper 2 cell ratio using a novel method of detecting intracellular cytokines, the Magnetic Activated Cell Sorter Cytokine Secretion Assay (MACS Assay). Comparisons were made between patients receiving autologous blood or no blood transfusion, for pre- and post-operation levels of interferon-gamma and interleukin-4. Interferon-gamma producing T-helper 1 cells decreased post-operatively. Concomitantly, interleukin-4 producing T-helper 2 cells increase. These results demonstrate a measurable shift from T-helper 1 to T-helper 2 cells post-operatively. Secondly, the study showed surgery alone instigates the same level of immunomodulation as autologous/cell salvage blood transfusion in combination with surgery.