Serological diagnosis of celiac disease

Celiac disease CD is an inflammatory disease of the small intestine brought about by exposure to gluten in genetically predisposed individuals. Celiac disease most often presents with non specific, or extra-intestinal, manifestations and, consequently, the disease remains under diagnosed. Untreated CD is associated with high morbidity and, therefore, early diagnosis is essential. The availability of non-invasive and relatively cheap serological tests has made it possible to screen large numbers of patients and resulted in increased, and earlier, diagnosis of patients with CD. However, these tests have varying degrees of sensitivities and specificities and the results generated can lead to a lot of confusion with regards to the diagnosis, or exclusion, of CD. In the present review, we discuss in detail these tests and suggest how they can be used in screening patients for CD with the hope that such information will help clinicians to select the right tests and interpret the generated results more effectively, and thus lead to improved identification and treatment of patients with CD

role of the clinical immunology laboratory in the diagnosis and monitoring of connective tissue diseases

Connective tissue diseases CTD are a group of autoimmune systemic diseases that can affect any organ-system in the body. The initial clinical presentations of these diseases overlap, not only with each other, but also with a wide range of other rheumatological and non-rheumatological disorders. Due to these reasons, clinicians depend heavily on the use of the clinical immunology laboratory for the diagnosis of CTD. A large number of tests exist in the laboratory for the investigation of CTD and each test can be performed by a number of different methods, each with its own limitations. Consequently, the significance of the results generated not only has to be interpreted in relation to the clinical picture, but also to the method used to generate the results. Moreover, within the laboratory, there is a hierarchical testing system for the investigation of CTD and if this system is used appropriately, in conjunction with the clinical picture, can result in the diagnosis/exclusion of CTD more efficiently and economically. In contrast, random use of the laboratory tests, combined with limited knowledge of the methods used to carry out these tests, can lead to delay or even misdiagnosis, as well as can lead to wastage of resources. In the following review, we have discussed the various tests that are used in the investigation of CTD, as well as the different methods used to carry out these tests, with the hope that such knowledge would lead to a more efficient and economical use of the clinical immunology laboratory in the investigation of CTD

Ineffectiveness of rat liver tissues in the screening of connective tissue disease

To assess the effectiveness of using rat liver tissues [RLT] for the screening of connective tissue disease [CTD]. Results of patient samples, submitted to the Clinical Immunology Laboratory, Birmingham Heartlands Hospital, Birmingham, United Kingdom for investigation of CTD between 2001 and 2002, were analyzed. Positive results for anti-double stranded DNA [dsDNA] antibodies and anti-extractable nuclear antigen [ENA] antibodies were correlated with the results of the corresponding anti-nuclear antibodies [ANA], obtained by indirect immunofluorescence [IIF] using RLT. In the second part of the study samples that were previously tested positive for anti-ENA or anti-dsDNA antibodies, were investigated prospectively for ANA using both RLT and human epithelial [Hep-2] cell line. The IIF method employing RLT for screening of CTD, failed to detect ANA patterns from 45% and 25% of patient samples know to contain antibodies to dsDNA and ENA. The anti-dsDNA antibodies that failed to be detected by the RLT were of low avidity and their clinical significance is unknown. In contrast, the antibodies to ENA were mostly directed against the Ro antigen and a clear marker of CTD. Hep-2 cell line enhanced the detection rate of anti-ENA antibodies, particularly those against the Ro antigen. In contrast, and like RLT, Hep-2 cell line failed to detect the low avidity anti-dsDNA antibodies. The present study has clearly shown that RLT are ineffective for screening of CTD. It is recommended that laboratories, which are still using these tissues, should consider replacing them with the Hep-2 cell line

Elucidation of the mechanisms of hairy-cell localization in tissues and the process of the bone marrow fibrosis in hairy-cell leukemia

Hairy cell leukemia is a chronic B cell leukemia with a number of distinctive features including the unusual tissue distribution of the leukemic cells, hairy cells, and the bone marrow fibrosis. We have been working, for a number of years, on the potential mechanisms behind hairy-cell localization in tissues. In this review, it is summarized how our work has shed very important information regarding these mechanisms and led, eventually, to the full elucidation of the process of the bone marrow fibrosis in hairy cell leukemia

CD44 mediates polymorphonuclear leukocyte motility on hyaluronan

To investigate the behavior of polymorphonuclear [PMN] leukocytes on the extracellular matrix carbohydrate component, hyaluronan [HA], in the presence and absence of the chemokine, interleukin-8 [IL-8]. The present study was conducted at the Department of Hematology, University of Liverpool, United Kingdom, between the period 2000 to 2001. Polymorphonuclear cells were isolated from whole venous blood using Mono-Poly-Resolving Medium. Purified PMN were added alone or with IL-8 to HA-coated plates and the behavior of these cells monitored by time-lapse video microscopy over a period of 40 minutes. For the identification of surface receptor[s] mediating PMN migration on HA, PMN were incubated with blocking and non-blocking antibodies against cluster of differentiation 44 [CD44] and Receptor for Hyaluronan Mediated Motility [RHAMM] prior to addition to HA-coated surfaces. Approximately 55% of PMN were found to interact and migrate on HA-coated plates with a mean speed of 6.4 +/= 0.7 mm/min. Addition of IL-8 reduced both the percentage moving cells [7.5%] and the average speed of the remaining moving cells [2.0 +/= 0.3 mm/min]. The inhibitory effect of IL-8 on PMN migration was associated with reorganization of the cytoplasmic fibrillar form of actin. Anti-CD44 blocking antibody substantially reduced the speed of PMN [2.5 +/= 0.9 mm/min], while non-blocking anti-CD44 and anti-RHAMM antibodies had no effect. The present study demonstrates for the first time that PMN are able to interact and migrate on the widely distributed extracellular matrix component, HA, using the cell surface receptor, CD44. Such interaction is modified by the chemokine, IL-8, in a way that optimizes the host defense against invading pathogens

Regulation of polymorphonuclear leukocyte function by platelets

To investigate the full effect of platelet-derived constituents on various polymorphonuclear neutrophil leukocyte responses. Polymorphonuclear neutrophil leukocytes and platelets were separated from fresh blood of normal healthy volunteers. Platelets were then stimulated partially, or maximally to release constituents of their a- or a- and dense granules. The effects of these constituents on polymorphonuclear neutrophil leukocyte function [oxidase activity, degranulation and migration] were investigated. Platelet-derived constituents were found to both enhance, and inhibit polymorphonuclear neutrophil leukocytes-oxidant production, depending on the incubation time. Enhancement was due to dense granule-derived nucleotides [adenosine diphosphate and adenosine diphosphate], while inhibition was due to adenosine monophosphate derived from these nucleotides by polymorphonuclear neutrophil leukocyte surface nucleotidases. This latter inhibitory effect was reversed by the cytokine, granulocyte-macrophage colony stimulating-factor. Moreover, platelet constituents consistently enhanced other polymorphonuclear neutrophil leukocyte responses including degranulation and migration regardless of the incubation period. The latter enhancement was due to a-granule constituents, most likely platelet factor 4. Platelets, through release of their granular constituents, are able to modulate polymorphonuclear neutrophil leukocyte function in a way that is physiologically beneficial