1998 Jan;72(1):95C103. can also present with nodules or consolidation that resembles fungal pneumonia.84,85 Non-infectious Non-infectious pulmonary complications can also present with signs and symptoms that may be much like CMV. Idiopathic pneumonia syndrome presents with cough and tachypnea often seen in CMV pneumonia, and has associated multilobular infiltrates on chest x-ray or CT.103 As a subgroup of these patients, patients with diffuse alveolar hemorrhage (DAH) usually present more acutely.103 Patients who develop non-infectious cryptogenic organizing pneumonia (COP) can also present with low grade fever, non-productive cough, and dyspnea much like CMV pneumonia.104 Radiologic manifestations can mimic viral pneumonia.105 The development of pulmonary edema or patients who develop chemotherapy associated pulmonary complications can also mimic CMV CRE-BPA pneumonia.106 Other medications, such as Sirolimus, can lead to adverse pulmonary complications that may present with interstitial pneumonitis much like CMV pneumonia or viral course of action.107 THERAPY Antiviral therapy The foundation for CMV pneumonia treatment is the early institution of antiviral therapy. CMV pneumonia following HCT, before the availability of current antivirals, was associated with a high mortality rate (nearly 100%). HCT recipients who receive early antiviral intervention may have improved end result from CMV pneumonia.108 Early treatment is thought to help control viral replication which may help to limit immune-related lung damage, thereby reducing additional morbidities, such as the development of secondary Naproxen sodium infections, need for mechanical ventilation and aggressive intensive care management. Still, antiviral therapy will not switch the outcome in all patients, as even with active antiviral therapy, death from CMV pneumonia remains an unavoidable end result in many patients.7,16,109 Therapy is focused on an induction phase (twice daily dosing) and a maintenance phase (once daily dosing) of treatment. At our center Naproxen sodium patients with CMV pneumonia receive a minimum 3 weeks of induction therapy and at least 2 weeks of maintenance, but patients with more severe disease or slower responses to therapy may need prolonged therapy. First collection therapy of CMV pneumonia is usually intravenous (IV) ganciclovir (GCV). GCV is usually nucleoside analogue of 2′-deosygaunosine, that undergoes initial phosphorylation by viral kinases encoded by CMV UL97 open reading frame (ORF).110 The active form of the drug, triphosphorylated GCV, competitively inhibits DNA synthesis catalyzed by CMV DNA polymerase (encoded by the UL 54 ORF).110 The use of GCV is limited by hematologic side effects, primarily by neutropenia, which restrict its Naproxen sodium use in the pre-engraftment phase of transplantation. IV GCV is recommended therapy for CMV pneumonia, although valganciclovir (the L-valyl ester of GCV) is usually available for oral dosing, it is not typically recommended for HCT patients with CMV pneumonia. Valgancyclovir can be considered for maintenance therapy in lower risk patients who have exhibited clinical response to therapy. An alternate to GCV, foscarnet functions by inhibition of CMV viral polymerase.110 Nephrotoxicity is the major adverse side effect of the drug, and can lead to acute renal failure, as well as Naproxen sodium mineral and electrolyte abnormalities. Because of these serious side effects, foscarnet is considered the second collection therapy but is preferred in subjects with myelosuppression and for patients with known resistance to GCV. Cidofovir functions as a competitive inhibitor of DNA polymerase that has been shown to be effective in CMV ocular disease.110,111 Many consider cidofovir a third collection agent, due to its significant renal and hematologic toxicities. Combination therapy is sometimes considered in patients with evidence of drug resistance (examined in detail elsewhere112) or in those with refractory disease. Novel antiviral options have generally been analyzed in the context of CMV prophylaxis, so data on their efficacy in treatment of disease are inadequate to support the use of any of these brokers as main therapy. Maribavir (MBV), is an orally bioavailable drug that interferes with DNA synthesis of CMV, and is also felt to inhibit viral encapsidation and nuclear egress of viral particles by binding to UL97 viral protein kinases.113 MBV has been used as salvage therapy for patients.