Pathology/Lab Coding Alert

After years of being stuck with 86805-86822 for human leukocyte antigen (HLA) testing, you need to come up to speed with CPT 2010 and 2009 changes that provide some new options.

Let our experts guide you through the maze of new codes -- and revised CPT instructions -- that alter how you should report HLA typing and crossmatch for transplant patients.

Resource: If you're new to transplant testing, you might want to first read "Keep HLA Codes Straight With This Transplant Primer" on page 19 for a concise introduction.

CPT provides the following four codes for HLA typing using serologic methods, which labs have used for years:

• 86812 HLA typing; A,B, or C (e.g., A10,B7, B27), single antigen

• 86813 ... A, B, or C, multiple antigens

• 86816 ... DR/DQ, single antigen

• 86817 ... DR/DQ, multiple antigens.

Recognize "class" terminology: The lab report might state that the test was for "HLA class I antigens." To select the proper code, you'll need to know how the class terminology aligns with the code definitions. "Class I refers to A, B, and C, while class II refers to certain DQ and DR antigens," explains Walter Herczyk, CHS, MT ASCP,laboratory manager for the Transplant Immunology & Immunogenetics Laboratory at University of Chicago Medical Center.

Many labs now perform HLA typing using molecular diagnostics methods instead of serologic testing. How should you report these tests?

Problem: "Until 2009, AMA direction published in CPT Assistant indicated that you should continue to use 86812-86817, even if the lab performed HLA typing by molecular diagnostics techniques such as high resolution polymerase chain reaction (PCR)," explains Diana Voorhees, MA, CLS, MT (ASCP) SH, CLCP, principal with DV and Associates Inc. in Salt Lake City.

Solution: CPT 2009 added the following instruction following code 86822: "For HLA typing by molecular pathology techniques, see 83890-83914 with appropriate genetic testing modifiers 4A-4G." That instruction frees your lab to garner more appropriate pay by selecting the molecular diagnostics codes that describe each step of a specific HLA typing test.

For instance: For HLA typing using PCR for 15 sequence specific oligonucleotide probes (SSOP), you should report the following codes:

• 83891 -- Molecular diagnostics; isolation or extraction of highly purified nucleic acid, each nucleic acid type (i.e., DNA or RNA)

• 83896 (x15) -- ... nucleic acid probe, each

• 83898 -- ... amplification, target, each nucleic acid sequence

• 83912 -- ... interpretation and report.

Caveat: Using the molecular diagnostics codes might result in billing for a high number of probes that appears to inflate reimbursement compared to actual costs, according to Voorhees. "Some payers are pushing for array codes" to describe HLA testing involving many probes, she adds.

Watch for modifier: Although CPT directs you to use genetic testing modifiers 4A-4G, as appropriate, many payers don't recognize these. "One of the big problems is that labs may perform A, B, and DR as a first level check, so you'd need three modifiers [4A, HLA-A; 4B, HLA-B; and 4E, HLA-DR]," Voorhees says.

CPT provides serology codes for crossmatch tests as follows:

• 86805 -- Lymphocytotoxicity assay, visual crossmatch; with titration

• 86806 -- ... without titration

• 86807 -- Serum screening for cytotoxic percent reactive antibody (PRA); standard method

• 86808 -- ... quick method.

These tests are time consuming and entail a slow turn around time -- they involve mixing donor and recipient serum and looking for some kind of reaction like agglutination or precipitation, Voorhees explains.

Key: Tests described by 86805-86808 all involve "cytotoxicity" methods, which means performing some kind of assessment of cell death upon serum mixing.

Like HLA typing, some HLA crossmatch testing also has moved beyond older serology methods, and CPT 2010 provides the following two new codes to capture the work:

• 86825 -- Human leukocyte antigen (HLA) crossmatch, non-cytotoxic (e.g., using flow cytometry); first serum sample or dilution

• +86826 -- ... each additional serum sample or sample dilution (List separately in addition to primary procedure).

"These codes are a welcome addition," Voorhees says.` "The codes describe crossmatch tests that can provide a more accurate measure of the antigen/antibody reaction for a better prediction of transplant success."

Using flow cytometry methodology, labs can detect low levels of antibody not detected by lymphocytotoxic crossmatch procedures. If the results suggest a reaction, the lab can perform a dilution and determine a more accurate quantification of the reaction.

Do this: "You should report 86825 for the first serum sample or dilution, and add +86826 each time the lab tests another serum sample or performs an additional dilution to quantify the strength of the antigen/antibody reaction," says William Dettwyler, MT-AMT, president of Codus Medicus, a laboratory coding consulting firm in Salem, Ore.

Watch for edits: Codes 86825 and 86826 are comprehensive -- you shouldn't additionally report flow cytometry method codes 88184-88189 (Flow cytometry, cell surface, cytoplasmic, or nuclear marker, technical component only; ...) or cell count codes 86355 (B cells, total count) or 86359 (T cells; total count) for the service.

A CPT text note and Correct Coding Initiative (CCI) edits restrict coding these services together.