DIARECT Newsletter



Dear Madam or Sir,

In 2016, the 68th AACC is at home in Philadelphia, PA.  Each year this event serves the global clinical market and, as in previous years, DIARECT will be attending this leading event for laboratory medicine and would like to invite all attendees to stop by our booth #4041.

For more information on our products please feel free to contact us at:

Email  info@diarect.com
Tel.     +49 761 47979-0

Pleasant reading!


New Product Line: Humanized Monoclonal Antibodies

Technological breakthroughs and innovative technologies continue to shape the in vitro diagnostic field. One of these advances in assay development are chimeric monoclonal antibodies for use as positive controls, or calibrators in IVD kits as an alternative to characterized disease state plasma.

Enzyme-linked immunoassays for the detection of antibodies in patient samples require reference material to determine cut-off values and test assay integrity, and these are then included in the kit as calibrators or positive controls. Most often this reference material consists of pools of disease state serum or plasma, but main drawbacks of these standards are their limited availability and variability, and there are also safety and ethical issues. What is required is a virtually unlimited supply of antibodies with a consistent concentration, specificity and avidity.

Chimeric monoclonal antibodies are produced in transgenic mouse strains in which the sequence for mouse IgG1 Fc region is substituted with the human sequence. After mouse immunization and hybridoma technology, antibodies are generated that retain a human constant region required for recognition by the anti-human conjugate. These monoclonal antibodies can then be produced using standard cell culture technologies.

At DIARECT we have obtained the first set of chimeric monoclonal antibody standards that can be used in the development of kits for autoimmune liver disease. LC1 humAb IgG, LKM humAb IgG and PDC-E2 humAb IgG can specifically detect LC1, LKM1, and PDC-E2 (Figure 1).

For questions or additional information please feel free to contact us at:
Tel: +49 761 47979-0
Email: info@diarect.com

Product Launch: Nucleosomes

Reports list more than 116 associated autoantibodies with varying diagnostic utility and correlation for the detection of lupus subtypes (Cozzani et al., 2014). Especially in the systemic form of lupus erythematosus (SLE), autoantibodies directed to nuclear (ANAs), cytoplasmic and cellular membrane antigens are considered an important serological characteristic.

In SLE the presence of anti-chromatin antibodies against the intact nucleosome and its individual components: dsDNA and histones, is associated with renal involvement, a major complication of the disease.

Anti-nucleosome antibodies (ANuAs) are a large family of autoantibodies directed against epitopes that are created by the interaction between dsDNA and core histones. A meta-analysis by Bizzaro et al. in 2012 has found that along with dsDNA antibodies, ANuAs are the first ones to appear during the course of SLE. They can be quantitatively assessed to evaluate disease activity and recently, with newer immunoassay platforms available, they have been found to be excellent SLE markers, particularly when anti-dsDNA antibodies are not present.

To complement our extensive panel of well-established ANA’s, DIARECT is now introducing a nucleosome antigen purified from bovine tissue.

Bizzaro et al. (2012) Autoimmunity Reviews. 12: 97-106
Cozzani et al. (2014) Hindawi Autoimmune Diseases. Article ID 321359, 13 pages

For questions or additional information please feel free to contact us at:
Tel: +49 761 47979-0
Email: info@diarect.com

New Infectious Serology Antigens: Yersinia YopB and YopE

Yersinia enterocolitca is a gram negative coccobacillus that is the causative agent of Yersiniosis, common symptoms of which are fever, abdominal pain and diarrhea. Occasionally, some people develop joint pain, most commonly in the knees, ankles or wrists. These joint pains, also known as reactive arthritis, usually develop about one month after initial symptoms. In patients with chronic Lyme-Borreliosis, characterized by the presence of reactive arthritis, a significant number of co-infections could be traced back to Y. enterocolitca. In sera from these patients, cross-reactivity with Yersinia outer membrane proteins (Yops) and Borrelia proteins have been found (Golkocheva-Markova et al., 2008). Therefore it appears that a precise result for the causative agent is necessary to correctly diagnose reactive arthritis. A sensitive and specific serological detection of Yersinia infection, with and without arthritis, can be increased by the incorporation of relevant immunogenic parameters. Antibodies of different isotypes (IgG, IgA and IgM) are formed against Yop proteins (YopM, YopD, YopN and YopH), as well as other relevant virulence factors (LcrV) of Yersinia enterocolitica.

YopB serves as an adapter protein and is a crucial component in the pore-formation process during infection. Translocators YopB and YopD form a channel for the T3SS needle complex and enable the delivery of Yop effectors into the host cells. YopE, a GTPase activation protein, is one of the translocation regulators and is also implicated in controlling pore formation. These processes depend on deactivation of small Rho GTPase, leading to inhibition of actin polymerization.

To offer a more comprehensive spectrum of Yersinia antigens for the development of diagnostic assays, we have extended our existing Yersinia product line with YopB and YopE. Both antigens are produced in the baculovirus/insect cell system (Figure 2).

Golkocheva-Markova et. al (2008) Clinical Microbiology and Infection 14: 873-875

For questions or additional information please feel free to contact us at:
Tel: +49 761 47979-0
Email: info@diarect.com


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