Process for multi-analyses of rare cells extracted or isolated from biological samples through filtration

Abstract

A process for isolating or extracting rare cells from a biological sample comprising filtering a biological sample, which may be treated or diluted, through a filter that has a pore size, pore density or other physical properties that retain rare cells, but which permits other kinds of cells to pass through the filter. This process also comprises multiple analyses performed on rare cells after their extraction or isolation by filtration to diagnostically identify the presence of rare cells in a biological sample and to use their diagnostic identification and molecular characterization for diagnostic purposes such as for early diagnosis of diseases, namely for early diagnosis of cancer and to select, guide, monitor treatments and in particular to select targeted treatments and to monitor the response and / or resistance to them. A kit comprising tools, equipment and / or reagents to accomplish both the filtration step and various kinds of multiple analyses performed after isolation and extraction of the rare cells by filtration.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 61 / 651,437, filed May 24, 2012 which is incorporated by reference in its entirety.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The invention involves the isolation of rare cells from biological samples by filtration and the subsequent analysis of these rare cells and their components. Rare cells have features or appear in biological samples at frequencies that distinguish them from other kinds of cells. Types of rare cells include rare tumor or rare cancer cells, rare kinds of endothelial cells, rare fetal cells and rare infected white blood cells (leukocytes).[0004]2. Description of the Related Art[0005]Rare Cells.[0006]Rare cells are present in absolute or relative low numbers in biological samples obtained from humans or animals. The presence of rare cells frequently correlates with a particular disease, disorder or condit...

AI Technical Summary

Benefits of technology

This patent describes various ways to analyze rare cells for diagnostic and therapeutic purposes. These methods include using quantitative and qualitative analysis of rare cells isolated by filtration, as well as multiple analyses on the same rare cells. The methods also include isolating non-fixed rare cells and performing RNA analysis on them, as well as using rare cells for early diagnosis of invasive cancers and for non-invasive prenatal diagnosis of genetic disorders. The patent also includes evaluating the effect of a candidate drug or treatment on the molecular characteristics of rare cells and selecting a drug or treatment that reduces the number of rare cells or modifies their molecular or immunological characteristics.

Problems solved by technology

However, these methods do not address the triple challenge of extracting or isolating of rare cells with (i) minimal or no loss, (ii) extraction or isolation of rare cells with minimal or no selection bias, and (iii) extraction or isolation of rare cells in a way that permits their facile or simultaneous use in multiple analytic procedures.

Methods that only recover some of the rare cells in a sample quantitatively impair the use of the isolated or extracted rare cells in subsequent analytic procedures.

These methods can also introduce selection bias.

Selection bias occurs when an extraction or isolation method leads to loss of one or several types of selected rare cells in a sample.

For example, a method that isolates tumor cells from a blood sample by binding the rare tumor cells to anti-epithelial cell antibodies results in the loss of rare tumor cells that do not express epithelial cell antigens that bind to the antibody.

Harsh extraction or isolation procedures or procedures that otherwise change the detectable features of the isolated or extracted rare cells compromise their use in subsequent analytic procedures.

However, if only molecular analyses targeting gene mutations are performed without analyses aiming to diagnose the presence or absence of tumor cells in blood, the test's result can be affected by bias.

Despite recent advances in the management of resected lung cancers and more effective treatment of metastatic tumors, the cure rate of patients with lung cancer remains low.

Moreover, the presence and number of CTCs were associated with worse prognosis [15].

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