Case 1
A 33-year-old man presented with fever, dyspnea, and odynophagia. Five months prior to admission, the patient had been treated for dental caries at a local hospital, and at that time examination revealed seropositivity for human immunodeficiency virus. On admission, temperature was 39.0'C, pulse 92 beats per minute, respiratory rate 20 breaths per minute and blood pressure 130/80 mmHg. Physical examination revealed oral thrush, consistent with findings of extensive esophageal candidiasis in endoscopic gastroduodenscopy performed five days before admission. Laboratory data on admission revealed a WBC count of 1,760/uL, Hb 10.9 g/dL, and platelet count of 297,000/uL. Arterial blood gas analysis while breathing room air revealed PaO2 of 48.0 mmHg, PaCO2 of 32.7 mmHg, and saturation of 88.5%, and the calculated (A-a)DO2 was 53.7. CD4 count and HIV viral load were 4/uL and 130,000 IU/mL, respectively. Diffuse bilateral infiltrates of both lung fields were noted, and no cystic lesions were observed on the chest X-ray and high resolution computed tomography (HRCT) taken on admission. Bronchoscopic alveolar lavage for diagnosis of P. jirovecii was carried out, and microscopic examination of the bronchoalveolar lavage fluid obtained showed P. jirovecii; no other microorganisms were detected by culture. Treatment with trimethoprim/sulfamethoxazole, fluconazole and corticosteroids at standard dosages was started. The patient had never been on HAART therapy prior to admission. HAART therapy was added to the treatment on the 8th hospital day. During the treatment with trimethoprim/sulfamethoxazole, pancytopenia worsened. Bone marrow biopsy revealed inflamed marrow and partial necrosis. Granulocyte colony stimulating factor was used without avail. On the 22nd hospital day, the chest X-ray obtained as the patient's hypoxemia worsened revealed pneumomediastinum. HRCT showed newly formed cystic lesions in both lung fields. Pneumomediastinum was treated conservatively with high oxygen supply. CD4 cell count and HIV levels were not followed during treatment. However, as the general condition of the patient deteriorated, the patient was started on intravenous pentamidine on the 23rd hospital day. On the 25th hospital day, his oxygen requirement increased. Without intubation, as the patient and guardian refused the patient being put on a ventilator due to multiple economical and sociological reasons, the patient died on the 26th hospital day.
Case 2
A 48-year-old man presented with insidious dyspnea that had developed over a period of 2 months. The patient had been seropositive for human immunodeficiency virus in 2005 in a routine physical examination for a job position as a sailor. He was on zidovudine and didanosine for 8 months but stopped taking these antiretroviral agents at another hospital for economic reasons. On admission, temperature was 38.2'C, pulse 96 beats per minute, respiratory rate 22 breaths per minute, and blood pressure 100/60 mmHg. Physical examination was normal except for decreased breathing sound in both lung fields. Laboratory data showed a WBC count of 11,010/uL, Hb 13.6 g/dL, a platelet count of 425,000/uL, and LDH of 1,095 U/L. Arterial blood gas analysis in room air demonstrated PaO2 of 54.1 mmHg, PaCO2 of 34.4 mmHg, and saturation of 89.9%, and the calculated (A-a)DO2 was 45.5. CD4 count and HIV viral load were 21/uL and 260,000 IU/mL, respectively. Chest X-ray on admission revealed diffuse ground glass opacity in both lung fields. HRCT showed interlobular septal thickening of the bronchus and bronchioles without any cyst formation (Figure 1). Microscopic examination of bronchoalveolar lavage revealed P. jiroveci, and Staphylococcus aureus was detected by culture. The patient met the criteria of respiratory failure [PaO2 less than 70 mmHg or (A-a)DO2 more than 35 mmHg] and corticosteroids were co-administered with trimethoprim/sulfamethoxazole. On hospital day 4 the patient developed sudden chest pain radiating to the shoulder and neck. Chest X-ray, electrocardiography, and arterial blood gas analysis were performed. The chest X-ray revealed air lining the cardiac border, indicating development of pneumomediastinum. HRCT revealed newly developed cystic changes, bronchiectatic change, and parenchymal tear (Figure 1). The pneumomediastinum was treated conservatively with administration of high oxygen supply without the need for invasive procedures. On hospital day 10, HAART was started with lopinavir/ritonavir, lamivudine, and zidovudine. On hospital day 13, follow up HRCT revealed more aggravated pneumomediastinum, bronchiectasis and parenchymal tear in the lingular division of the left upper lobe. Trimethoprim/sulfamethoxazole was changed to intravenous pentamidine. The patient experienced nausea, vomiting, and hypoglycemia on pentamidine, leading to a further change of antibiotics to primaquine and clindamycin. The patient's dyspnea improved and no particular complications were observed. The patient was discharged on the 42nd hospital day and is being followed up in the outpatient clinic.