Lymphoma in HIV Patients: MTB Negative, CD4 Count >200

Why Lymphoma Still Occurs at CD4 >200?

"Even in the face of effective ART, the overall rate of lymphoma in the HIV-infected population remains elevated, even in those with normal CD4+ T-cell counts. Most of the lymphomas that arise in patients with preserved CD4 T-cell counts are not associated with EBV or HHV8."

• Class switching
• Somatic hypermutation via Activation-Induced Cytidine Deaminase (AID)

Types of Lymphoma Most Likely at CD4 >200 (MTB Negative)

Harrison's Principles (22nd Ed., 2025): "Systemic lymphoma is seen at earlier stages of HIV infection than primary CNS lymphoma. In one series the mean CD4+ T cell count was 226/μL."

Two Pathogenic Mechanisms (Robbins & Cotran)

• Occurs early in HIV infection
• AID-dependent DNA breaks → oncogene translocations
• Produces Burkitt lymphoma (MYC translocation) and DLBCL (BCL6 translocation)
• These are EBV/HHV8-negative - more typical in patients with preserved immunity

• T-cell depletion removes EBV/KSHV surveillance
• Activated EBV-infected B-cell clones proliferate and acquire mutations
• Produces EBV+ large B-cell lymphoma, HHV8+ Primary Effusion Lymphoma (PEL), and EBV+ Hodgkin lymphoma
• More typical at lower CD4 counts

Clinical Presentation (Harrison's 22E)

• >80% present with extranodal disease (CNS, gut, orbit, lungs, bone marrow)
• B symptoms (fever, night sweats, weight loss) in ~80% of cases
• Oral cavity involvement (immunoblastic lymphoma of hard palate) is characteristic
• Ann Arbor stage is typically advanced (Stage III-IV) at presentation
• Performance status is often poor

Why MTB Negative Matters Here

1. AIDS-related systemic lymphoma (especially DLBCL, Burkitt) - most likely
2. Hodgkin lymphoma - do not miss; significantly elevated risk
3. Multicentric Castleman disease (HHV8-associated; can mimic lymphoma)
4. Primary effusion lymphoma (PEL) - presents as pleural/peritoneal effusions

Summary Table

• Robbins, Cotran & Kumar Pathologic Basis of Disease (10th Ed.), pp. 244-245 - on B-cell lymphoma pathogenesis and CD4-independent mechanism
• Harrison's Principles of Internal Medicine (22nd Ed., 2025), p. 1657 - on types, CD4 thresholds, and CNS vs systemic lymphoma
• Henry's Clinical Diagnosis and Management by Laboratory Methods - HIV-associated lymphomas section

Lymphoma in HIV Patient on ART >2 Years, CD4 >200, MTB Negative

The Core Paradox: Why Lymphoma Despite ART?

"Although efficiently managed by cART, chronic HIV infection remains associated with a high incidence of malignant lymphomas."

"Even in the face of effective ART, the overall rate of lymphoma in the HIV-infected population remains elevated, even in those with normal CD4+ T-cell counts."

Mechanism 1: Persistent Germinal Center Dysregulation (Most Important at CD4 >200 on ART)

• Profound germinal center B-cell hyperplasia
• Chronic AID (Activation-Induced Cytidine Deaminase) activity
• Error-prone somatic hypermutation and class switching → oncogene translocations (MYC, BCL6)

• EBV-negative, HHV8-negative
• Burkitt lymphoma (MYC translocation) or DLBCL germinal-center subtype (BCL6)
• More likely at relatively preserved CD4 counts

Goldman-Cecil Medicine: "Although the risk for HIV-associated Burkitt lymphoma increases with advancing immunodeficiency, it may be seen in patients with relatively preserved CD4 cell counts. Antiretroviral therapy reduces but does not eliminate the risk for Burkitt lymphoma in HIV-1-infected persons."

Mechanism 2: Immune Reconstitution and Unmasking (IRIS-Type Lymphoma)

Mechanism 3: Ongoing Chronic Immune Activation

• Persistent microbial translocation from the gut → chronic systemic inflammation
• Elevated IL-6, IL-10 (B-cell growth factors)
• Residual immune dysregulation

Which Lymphoma Type Is Most Likely?

The ART-Era Paradox for Hodgkin Lymphoma

Harrison's 22E: Hodgkin lymphoma does not share the dramatic decrease seen with other AIDS-defining conditions in the ART era. In fact, it may increase as CD4 recovers, because the inflammatory microenvironment around Reed-Sternberg cells depends on reconstituted immune effector cells.

Harrison's: "The incidence of AIDS-associated systemic lymphomas has not experienced a dramatic decrease as a consequence of the widespread use of effective ART."

Harrison's on MCD: "While the incidence of Kaposi's sarcoma has decreased, the incidence of multicentric Castleman's disease has increased in the setting of ART."

Clinical Presentation on ART

Diagnostic Approach

MTB negative + CD4 >200 + on ART >2 years + lymphadenopathy/mass
                        ↓
         Lymphoma must be ACTIVELY excluded
                        ↓
    1. Excisional biopsy (preferred over FNA)
       → Histology + immunophenotype (CD20, CD10, BCL6, MUM1, Ki-67)
       → EBV (EBER in-situ hybridization)
       → HHV8 (if effusion or suspected MCD/PEL)
       → FISH for MYC, BCL2, BCL6 (double/triple hit lymphoma)
    2. Staging CT chest/abdomen/pelvis (PET-CT preferred)
    3. Bone marrow biopsy
    4. LP if any neurological symptoms (CSF EBV PCR if CNS lesion)
    5. HIV viral load + CD4 count (confirm ART efficacy)
    6. Serum LDH, uric acid, beta-2 microglobulin

Management on ART

KJ Lee's Otolaryngology: "The standard treatment consists primarily of chemotherapy with concurrent ART. The outcomes have improved in the ART era, with 3-year overall survival approaching 50% for all comers."

Harrison's 22E: "Response rates as high as 72% with a median survival of 33 months and disease-free intervals up to 9 years have been reported." Concerns about bone marrow toxicity overlap between ART and chemotherapy are mitigated by avoiding myelosuppressive antiretrovirals (e.g., zidovudine/AZT) during chemotherapy.

Prognosis Determinants in This Patient

• Age >60 years
• Advanced stage (III/IV)
• Elevated LDH
• Poor performance status (ECOG >1)
• More than one extranodal site
• Low CD4 at time of lymphoma diagnosis (despite being on ART)

• CD4 >200 (better immune reserve)
• Already on ART >2 years (viral suppression likely)
• MTB negative (no competing infectious burden)
• More likely to tolerate full-dose chemotherapy

Key Takeaway Points

1. ART does not eliminate lymphoma risk - it reduces but does not abolish it; germinal center dysregulation from prior HIV infection persists
2. Burkitt lymphoma and DLBCL are the most likely diagnoses at CD4 >200 on long-term ART - both often EBV-negative
3. Hodgkin lymphoma paradoxically increases with immune reconstitution on ART
4. Multicentric Castleman Disease incidence has risen in the ART era and mimics lymphoma
5. Concurrent ART + chemotherapy is standard; avoid myelosuppressive ARVs (AZT) during chemo
6. Outcomes are better in the ART era vs. pre-ART, with survival approaching that of HIV-negative lymphoma patients

• Robbins, Cotran & Kumar Pathologic Basis of Disease (10th Ed.), p. 244 - pathogenesis of B-cell lymphoma in HIV
• Harrison's Principles of Internal Medicine (22nd Ed., 2025), pp. 1656-1658 - lymphoma types, CD4 thresholds, treatment outcomes
• Goldman-Cecil Medicine (International Ed.) - Burkitt lymphoma on ART
• KJ Lee's Essential Otolaryngology - management regimens and survival data
• Dolcetti R et al., Cancers 2025 - PMID 40647389 - oncogenic pathways and therapeutic opportunities in ART-era HIV lymphoma