Deciphering TB Lab Reports Jessica Gentry Tuberculosis Laboratory Supervisor

Laboratory Regulation Laboratories performing diagnostic testing on human patient specimens are regulated by CLIA: Clinical Laboratory Improvement Amendments Regulations establish quality standards for laboratory testing performed on specimens from humans, such as blood, body fluid, and tissue, for the purpose of diagnosis, prevention or treatment of disease, or assessment of health. The purpose is to ensure high-quality testing.

Laboratory Regulation Examples of CLIA regulations: Qualified, trained personnel performing testing Laboratory inspections/audits Enrolled in Proficiency Testing Laboratory director overseeing testing Written procedures for testing Requirements for lab reports

Lab Reports Are Difficult to Read… Different tests performed by different laboratories PCR vs. probe vs. NAAT Use of abbreviations Inconsistent terminology Multiple dates—collection date, test date, report date Formatting Results not listed in chronological order Results from multiple laboratories on a single report Results moved through a variety of LIMS systems

What’s on a Lab Report? Laboratory Information Patient Information Specimen Information Lab Testing Performed Results Interpretation

Laboratory Information Laboratory Name Physical Address Laboratory Medical Director CLIA Certificate Number Referral Laboratory Information Department Mycobacteriology Tuberculosis AFB Lab Microbiology

Patient Information Required: Two patient identifiers, typically: Patient Name Unique Patient Identifier (MRN) Date of Birth Optional: Age Gender Race/Ethnicity Address

Specimen Information Specimen Source—sometimes listed as “site” Pulmonary (Respiratory): Sputum, bronchial Extrapulmonary: Urine, lymph node, CSF, tissue, etc. Descriptive modifiers sometimes added—Induced or expectorated sputum, tissue location, RUL, etc. Collection Date Received Date Accession Number/Specimen ID/Lab Number

Laboratory Tests Test Performed Test Result Normal vs. Abnormal Interpretation Units of Measurement Qualitative (QL) vs. Quantitative (QN) Date Test Reported

AFB Smear Microscopy Acid Fast Bacillus (AFB) Acid Fast Bacilli, Acid Fast Bacteria Digested, Concentrated, or Unconcentrated Smear AFB Stain Fluorescent Fluorochrome Auramine O-phenol

AFB Smear Microscopy AFB Negative No Acid Fast Bacilli seen/observed on smear AFB Positive Acid Fast Bacilli seen/observed/found on smear <1/field, 1-10/field, >10/field, >50/field 1+ (few), 2+, 3+, 4+ (many) Rare, Few, Moderate, Many

Molecular Assays Assays that detect genetic material (DNA) of MTBC: Polymerase Chain Reaction (PCR) DNA Probe MTB-RIF Nucleic Acid Amplification Test (NAAT) Negative, Not Detected Positive, Detected Testing can be in the specimen or culture Assays can also look for other mycobacteria—M. avium complex, M. kansasii, M. gordonae

Molecular Detection of Drug Resistance Detection of mutations associated with drug resistance Assays Pyrosequencing Sanger Sequencing Gene Xpert MTB/RIF Whole Genome Sequencing (WGS) Results Detected vs. Not Detected Mutation Present vs. Mutation Absent Cepheid GeneXpert Cartridge

Culture Results AFB culture is typically performed in tandem with an AFB smear Test names: AFB Cx, AFB Cx + Stn, AFB Identification (ID) Preliminary results may be reported at 2 wks, 4, wks, etc. Culture negative—usually reported at 6 wks Culture positive Organism isolated, Organism ID MTBC, MTB, Mycobacterium tuberculosis Method used for ID—PCR, probe, MALDI-TOF, etc.

Antibiotic Susceptibility Testing Antibiotic tested Critical concentration or MIC (Minimum Inhibitory Concentration) Sometimes multiple levels per antibiotic Result/interpretation R=Resistant S=Susceptible, Sensitive Method used Broth (MGIT) Agar Proportion (AP)

Conclusions Different labs use different test methods All labs report results differently Labs like to use abbreviations BUT—understanding what type of information is included in a lab report and knowing the keywords to look for can be very helpful ALSO—If you have questions, call the lab and ask!

Questions? Jessica Gentry Tuberculosis Laboratory Supervisor Indiana State Department of Health jgentry@isdh.in.gov Phone: (317) 921-5858