LUNGS IN HIV

TB IN HIV POSITIVE INDIVIDUAL
  • Tuberculosis can appear at any stage of HIV infection.
  • Mycobacterium tuberculosis is the Most common agent causing tuberculosis in AIDS patient in tropical countries
  • MAC infection occurs when CD4 + T cells counts are < 50/ml, in contrast M. tuberculosis infection develops early in the course with CD4 T cells counts > 300/ml.
  • In early stages TB can present as typical pattern as Upper lobe involvement with Cavitation without significant Lymphadenopathy or effusion.
  • In late stages TB can present as diffuse interstitial or Miliary pattern with little Cavitation with Lymphadenopathy. Active TB can accelerate course of HIV infection.<
  • br> Extrapulmonary TB is common in HIV Patients.
  • Mycobacterium tuberculosis can cause disease in HIV+ve patient with a CD4 count of 600/ cu.mm
The diagnosis of TB in HIV Patients is difficult because of:
  • increased sputum negativity
  • atypical radiography
  • lack of classic granulomas
  • Negative PDD skin tests.
  • World wide about one third of all AIDS related deaths are due to TB.
  • Clinical manifestations 'depend on CD4 CELL COUNTS.'
  • In patients with low CD CELL COUNTS, Disseminated disease is more common.
  • Pleural effusions, Miliary spread, Lymphadenopathy and bilateral reticulonodular pattern is seen.
  • In patients with High CD4 CELL COUNTS, Typical pattern as Upper lobe involvement with Cavitation without significant Lymphadenopathy or effusion is seen.
  • Heart disease is a common post mortem finding in HIV infected patients.
  • 'Paradoxical reactions' (Exacerbations in signs and symptoms) have been reported with administration of HAART.
Antituberculous Drugs:
First-line agents for the treatment of tuberculosis:

  • Isoniazid,
  • Rifampin,
  • Pyrazinamide,
  • Ethambutol, and streptomycin
Second-line drugs are used only for the treatment of patients with tuberculosis resistant to first-line drugs. Included in this group are the injectable drug
  • Kanamycin, amikacin, and capreomycin and the oral agents
  • Ethionamide, cycloserine, and PAS, ofloxacin, levofloxacin and sparfloxacin. Other second-line drugs include clofazimine, amithiozone (thiacetazone)o?
  • The treatment regimen of choice for virtually all forms of tuberculosis in both adults and children consists of a 2-month initial phase of isoniazid, rifampin, and pyrazinamide followed by a 4-month continuation phase of isoniazid and rifampin. 
  • Except for patients who seem unlikely on epidemiologic grounds to be initially infected with a drug-resistant strain, ethambutol (or streptomycin) should be included in the regimen for the first 2 months or until the results of drug susceptibility testing become available.
Tuberculocidal drug                    Isoniazid, Rifampin, Pyrazinamide, Streptomycin
Tuberculostatic drugs                 Ethambutol Thiacetazone, PAS, Ethionamide, Cycloserine.
 PNEUMONIA IN AIDS:
Symptomps Dyspnea and non- productive cough

  • x-ray shows bilateral perihilar opacities without pleural effusion and lymphaden-opathy
  • Bronchoalveolar lavage that demonstrates small, "hat-shaped" structures in alveoli that are about the size of an erythrocyte and stain with silver stains.
  • The most characteristic histopathological feature of pneumocystis carinii pneumonia in adults is predominantly alveolar, foamy vacuolated, eosinophilic exudates.
  • Interstitial pneumonitis is usually mild and shows infiltration with PML and mononuclear cells.
Prophylaxis Against Pneumocystis Pneumonia in HIV Positive
  • Patients with CD4 counts below 200 cells/mcL, a CD4 lymphocyte percentage below 14%, or weight loss or oral candidiasis should be offered primary prophylaxis for Pneumocystis pneumonia.
  • Patients with a history of Pneumocystis pneumonia should receive secondary prophylaxis until they have had a durable virologic response to HAART for at least 3-6 months and maintain a CD4 count of > 250 cells/mcL.
Drugs used are:
  • Trimethoprim-sulfamethoxazole, Dapsone,
  • Atovaquone,
  • Aerosolized pentamidine
  • Pleconaril is an investigational drug active in vitro against picornavirus replication including over 90% of the most commonly isolated enterovirus types and 80% of rhinovirus serotypes.
Neuraminidase Inhibitors:
  • Neuraminidase inhibitors zanamivir and oseltamivir for both influenza A and influenza B.
  • Oseltamivir is indicated for the treatment of uncomplicated acute infection caused by influenza A virus in patients older than 1 year of age
  • Oseltamivir is indicated for the treatment of uncomplicated acute infection caused by influenza B virus in patients older than 1 year of age
  • Specific antiviral therapy is available for influenza: Amantadine and Rimantadine for influenza A
Exam Question
  • AIDS patient most common mico-organism responsible for pneumonia is Pneumocystis carinii
  • Mycobacterium tuberculosis is the Most common agent causing tuberculosis in AIDS patient in tropical countries
  • Mycobacterium tuberculosis can cause disease in HIV+ve patient with a CD4 count of 600/ cu.mm
  • The most characteristic histopathological feature of pneumocystis carinii pneumonia in adults is predominantly alveolar, foamy vacuolated, eosinophilic exudates.
  • Respiratory system infections in HIV is seen with Streptococcus, H.influenzae, Pneumocystis carinii
  • Chest X-ray findings in tuberculosis associated with HIV are Disseminated tuberculosis, Pleural effusion, Hilar lymphadenopathy
Don't Forget to Solve all the previous Year Question asked on LUNGS IN HIV