What diagnosis code should I use for a hepatitis B (hep B) panel when ordering Kesimpta (ofatumumab) start labs?

Diagnosis Code for Hepatitis B Panel When Ordering Kesimpta Start Labs

For Kesimpta (ofatumumab) initiation, you should use diagnosis code Z01.89 (Encounter for other specified special examinations) for ordering the hepatitis B panel as a pre-treatment screening test. 1

Rationale for HBV Screening Before Kesimpta

• Kesimpta (ofatumumab) FDA labeling explicitly requires hepatitis B virus (HBV) screening prior to initiating treatment 1
• Screening is mandatory because Kesimpta is contraindicated in patients with active HBV infection confirmed by positive results for HBsAg and anti-HBV tests 1
• For patients who are negative for HBsAg but positive for Hepatitis B core antibody (HBcAb+) or are HBV carriers (HBsAg+), consultation with liver disease experts is required before starting treatment 1

Components of the Hepatitis B Panel

The complete hepatitis B panel for Kesimpta initiation should include:

• Hepatitis B surface antigen (HBsAg) - to detect current infection 2
• Hepatitis B surface antibody (anti-HBs) - to assess immunity 2
• Hepatitis B core antibody (anti-HBc) - to identify previous or ongoing infection 2
• Hepatitis B e antigen (HBeAg) and antibody (anti-HBe) - to evaluate viral replication and infectivity 2

Interpretation of HBV Test Results

Possible scenarios and their implications:

• HBsAg positive: Indicates active HBV infection and is a contraindication for Kesimpta 1
• HBsAg negative, anti-HBc positive: May indicate previous infection or occult hepatitis B; requires liver disease expert consultation 1
• HBsAg negative, anti-HBs positive, anti-HBc negative: Indicates successful vaccination 3
• HBsAg negative, anti-HBs positive, anti-HBc positive: Indicates resolved HBV infection 3

Additional Required Testing for Kesimpta Initiation

Along with the hepatitis B panel, the following tests are also required before starting Kesimpta:

• Quantitative serum immunoglobulins 1
• Verification of vaccination status (especially for live vaccines which should be given at least 4 weeks prior to Kesimpta initiation) 1

Common Pitfalls to Avoid

• Pitfall #1: Using a diagnosis code for hepatitis B infection when the patient doesn't have confirmed HBV - this could create confusion in the medical record 3
• Pitfall #2: Ordering incomplete HBV testing - all components of the panel are necessary for proper risk assessment 2
• Pitfall #3: Failing to document the reason for testing as medication initiation screening, which could lead to insurance coverage issues 1

Coding Advice

• Z01.89 is the most appropriate code as it indicates screening for a specific purpose (medication initiation) rather than suspected disease 1
• If the patient has multiple sclerosis, include the appropriate MS diagnosis code as the primary diagnosis, with Z01.89 as a secondary code 1