Pathogenesis and Pathology of HIV/AIDS

Introduction to HIV and AIDS

Human Immunodeficiency Virus (HIV) is a retrovirus that targets the immune system, leading to progressive immunodeficiency and ultimately, Acquired Immunodeficiency Syndrome (AIDS). The disease progression is characterized by depletion of CD4+ T cells, opportunistic infections, and systemic complications.

HIV Structure and Replication

HIV is an enveloped virus with a lipid bilayer membrane, glycoprotein spikes (gp120, gp41), and a core containing RNA and reverse transcriptase. The replication cycle includes:

• Attachment and fusion to host CD4+ cells.
• Reverse transcription of RNA into DNA.
• Integration into the host genome via integrase.
• Transcription, translation, and assembly of new virions.
• Budding and release of new infectious particles.

Pathogenesis and Disease Progression

HIV infection leads to a gradual loss of immune function, categorized into three stages:

• Acute HIV infection – characterized by flu-like symptoms and high viral loads.
• Chronic HIV (Clinical Latency) – asymptomatic or mild symptoms with ongoing immune deterioration.
• AIDS – marked by severe immunodeficiency, opportunistic infections, and malignancies.

Clinical Manifestations

Patients with AIDS may present with recurrent infections, Kaposi's sarcoma, neurological complications, and wasting syndrome.

Conclusion

Understanding the pathology of HIV/AIDS is crucial for developing effective treatment strategies and public health interventions.