PULMONARY BOARD REVIEW: RARE LUNG SYNDROMES (NOT DISCUSSED ELSEWHERE) Parenchymal Disorders: 1. Acute Chest Syndrome a. Affects approx. 40% of all pts with SCD b. Most common in children and, when recurrent, can lead to chronic respiratory insufficiency c. Defined clinically with chest pain, fever and infiltrates on CXR d. Causes include infections (Chlamydia pneumoniae and Mycoplasma), in situ thrombosis, fat embolism (from bone infarction), and hypoventilation secondary to pain/narcotics e. Treatment: i. Transfusion in those with: Hypoxemia and/or resp. distress, h/o cardiac dz, Significant pain in extremities, Adults, Significant anemia, thrombocytopenia or multilobar pneumonia ii. Supplemental O2/Narcotic analgesia iii. Broad spectrum abx including Macrolide iv. Long-term tx with hydroxyurea (No role for acute management); causes increased production of fetal hgb v. Bronchodilators even in absence of bronchospasm because airway hyperresponsiveness is frequently present vi. Incentive spirometry has been shown to reduce pulmonary complications 2. Adult Onset Still’s Dz a. Still’s dz (Juvenile Rheumatoid Arthritis) is most frequent collagen vascular dz of childhood. Disease in adults is episodic in nature and occasionally mimicks sepsis and/or ARDS b. Salmon Colored Rash; macular rash c. Pulmonary involvement is commonDiffuse organizing alveolar damage; also can see pleural effusions and diffuse alveolar infiltrates, mediastinal LAN d. Pericarditis, hepatitis and glomerulonephritis can occur e. Other findings include arthralgias, sore throat, leukocytosis f. Hyperferritinemia helpful in confirming dx g. Tx is steroids 3. Felty’s Syndrome a. Extra-articular manifestation of severe rheumatoid arthritis b. Combination of arthritis, splenomegaly and leucopenia c. Recurrent local and systemic infectionsLeads to inc. morbidity/mortality d. Can occasionally present as acute upper airway obstructionAffects vocal cords 4. Familial Mediterranean Fever (FMF) a. Repeated courses of pleuritis without underlying parenchymal involvement which resolves rapidly and completely, allowing for good health between attacks; can be complicated by renal amyloidosis b. Autosomal recessive; chromosome 16; Pyrin/Marenostrin c. TxColchicine 1-2mg/d 5. Chronic Granulomatous Dz a. Refers to 4 genetic diseases (one is x-linked, 3 are autosomal recessive) in which phagocytes are deficient in respiratory burst oxidase activity. Neutrophils and other phagocytes are unable to manufacture oxidants such as H2O2 placing patients at risk of developing recurrent life-threatening bacterial and fungal infections (most commonly S. aureus, Enterobacter, Aspergillus). b. Pos. nitroblue tetrazolium test c. Lung bxgranulomas with microabscesses d. Can also use flow cytometry with dihydrorhodamine-123 fluorescence for dx e. TxChronic antibiotic prophylaxis (Bactrim) and subcutaneous injections of interferon-γ. Acute infections may require allogeneic granulocyte transfusions. Systemic steroids may be required for a few weeks to resolve granulomatous process 6. Acute Mountain Sickness (AMS) a. Most common high altitude syndrome b. Manifests within 12-96 hours after ascent c. h/a, fatigue, malaise, anorexia, nausea, sleep disturbance d. If severe, can manifest as pulmonary and cerebral edema e. HAPE (High Altitude Pulmonary Edema)develops within 24 hrsfever, leukocytosis, severe hypoxemia and diffuse alveolar infiltrates on CXR f. Risk factors for HAPE: Prior AMS, Younger age, male gender g. Prevention of AMS i. Gradual ascent and acclimatization at 2000 meters ii. Prophylactic slow release Nifedipine (20mg q8h) demonstrated to significantly reduce incidence of HAPE in susceptible climbers above 3700 meters iii. Acetazolamide (250mg q8h or 500mg q12h) is effective in preventing AMS by increasing nocturnal VE and preventing hypoxemia. Give 24-48 hrs prior to ascent and continue for 3 days of acclimatization iv. Dexamethasone 2nd line therapy of established HAPE Not recommended as preventative therapy h. Most effective tx of HAPE Descent to lower altitude 7. Alpha 1 Antitrypsin Deficiency: a. Made in the liver and circulates in blood b. Mostly northern europeans c. Hereditary deficiency – minor changes in gene coding produces alterations in structure of protein – more than 75 alleles detected i. Each allele has a name – preceded by Pi (protease inhibitor) ii. Everyone has two genes coding – maternal and paternal origin iii. Normal = PiMM (200 mg/dL) iv. PiZ – impaired transport from liver accumulates in liver and causes destruction there v. PiZZ (homozygous) – have 15% of normal (30 mg/dL) vi. PiMZ (heterozygous) – have 50-60% of normal d. PiZZ – strong risk factor for premature emphysema (30-40 yo), particularly if smoker e. Structural integrity of alveolar wall depends on balance b/w elastin degradation by elastase (released by PMNs and MPs) and protection by A1AT f. Panacinar emphysema – predominant in lower lung zones g. Tx: i. NO smoking!!! ii. Replacement therapy with Prolastin (pooled human plasma A1AT) – (Wewers NEJM, 1987; 316:1055-1062) – once weekly 60 mg/kg weekly for those with established emphysema – airflow obstruction (ATS guidelines) – well tolerated, expensive iii. No definitive randomized controlled trial iv. Don’t treat = liver disease, elderly, smokers v. Give HBV vax first – from pooled plasma 8. Lung Transplant: a. Acute Rejection: fever, dyspnea, cough i. First 3 months: abnormal CXR with peri-hilar infiltrate ii. > 3 months: usually normal CXR iii. perivascular lymphocytic infiltrate b. Chronic Rejection: B.O. (bronchiolitis obliterans), > 3 mths post TPx, worsening obstruction c. PTLD: homogenous proliferation of lymphocytes – NHL and B type i. Develop in first year ii. Associated with EBV – primary or reactivity iii. If EBV negative prior to TPx increased risk iv. Solitary to multiple pulmonary nodules v. Affects allograft and occasionally extra-pulmonary (CNS) vi. Tx: decrease immunosupression, XRT/chemo, acyclovir, ganciclovir, alpha interferon, lymphocyte activating killer cells 9. Hamartomas: a. Most common benign lung tumor and account for 5-10% of all SPN’s b. Malignant change is extremely rare c. Central cartilaginous area with other areas of myxomatous and fibroblastic tissue, muscular, adipose tissue, bronchial glands d. Typically well circumscribed, < 3 cm, lobulated e. Calcification in 10-15% (better seen on chest CT, cartilage or fat deposits) popcorn pattern