Manfred Herold

During the 12th International Workshop on Autoantibodies and Autoimmunity held in Sao Paulo, Brazil, on August 28, 2014, a full day session was devoted to establishing a consensus on the nomenclature of staining patterns observed in the antinuclear antibody (ANA) indirect immunofluorescence test on HEp-2 cells. The current report summarizes the collective agreements with input from the host Brazilian and international communities that represented research, clinical, and diagnostic service laboratories. Patterns are categorized in three major groups (nuclear, cytoplasmic, and mitotic patterns) and each pattern has been defined and described in detail. The consensus nomenclature and representative patterns are made available online at the international consensus on antinuclear antibody pattern (ICAP) website (www.ANApatterns.org). To facilitate continuous improvement and input, specific comments on ICAP are encouraged and these will be discussed in subsequent ICAP meetings. The ultimate goal with the establishment of the ICAP is to promote harmonization and understanding of autoantibody test nomenclature, as well as interpretation guidelines for ANA testing, thereby optimizing usage in patient care.

The indirect immunofluorescence assay (IIFA) on HEp-2 cells is widely used for detection of antinuclear antibodies (ANA). The dichotomous outcome, negative or positive, is integrated in diagnostic and classification criteria for several systemic autoimmune diseases. However, the HEp-2 IIFA test has much more to offer: besides the titre or fluorescence intensity, it also provides fluorescence pattern(s). The latter include the nucleus and the cytoplasm of interphase cells as well as patterns associated with mitotic cells. The International Consensus on ANA Patterns (ICAP) initiative has previously reached consensus on the nomenclature and definitions of HEp-2 IIFA patterns. In the current paper, the ICAP consensus is presented on the clinical relevance of the 29 distinct HEp-2 IIFA patterns. This clinical relevance is primarily defined within the context of the suspected disease and includes recommendations for follow-up testing. The discussion includes how this information may benefit the clinicians in daily practice and how the knowledge can be used to further improve diagnostic and classification criteria.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a potent angiogenic cytokine, and various inhibitory agents, including specific antibodies, have been developed to block VEGF-stimulated angiogenesis. We developed HuMV833, a humanized version of a mouse monoclonal anti-VEGF antibody (MV833) that has antitumor activity against a number of human tumor xenografts, and investigated the distribution and biologic effects of HuMV833 in patients in a phase I trial. METHODS: Twenty patients with progressive solid tumors were treated with various doses of HuMV833 (0.3, 1, 3, or 10 mg/kg). Positron emission tomography with (124)I-HuMV833 was used to measure the antibody distribution in and clearance from tissues. Magnetic resonance imaging was used to measure the vascular permeability surface area product with a first-pass pharmacokinetic model (k(fp)) to determine tumor vascular permeability. RESULTS: The antibody was generally well tolerated, although the incremental dose, phase I study design, and pharmacodynamic endpoints could not identify the optimum biologically active dose. Antibody distribution and clearance were markedly heterogeneous between and within patients and between and within individual tumors. HuMV833 distribution to normal tissues also varied among patients, but the antibody was cleared from these tissues in a homogeneous fashion. Permeability was strongly heterogeneous between and within patients and between and within individual tumors. All tumors showed a reduction in k(fp) 48 hours after the first treatment (median = 44%; range = 4%-91%). CONCLUSIONS: Because of the heterogeneity in tumor biology with respect to antibody uptake and clearance, we suggest that either intrapatient dose escalation approaches or larger, more precisely defined patient cohorts would be preferable to conventional strategies in the design of phase I studies with antiangiogenic compounds like HuMV833.