ABSTRACT. A 3-month-old infant of 33 weeks' gestation was hospitalized with pneumonia caused by Bordetella pertussis. Respiratory insufficiency worsened, and on hospital day 3, there was severe pulmonary dysfunction (arterial oxygen pressure/fraction of inspired oxygen ratio: 120), extreme leukocytosis (white blood cell count 104 000/mm 3 ), and severe pulmonary hypertension as assessed by 2-dimensional echocardiogram. A double volume exchange transfusion was performed to reduce the leukocyte mass. Oxygenation began to improve during the exchange and continued to improve over the ensuing 31 hours (arterial oxygen pressure/fraction of inspired oxygen ratio: 280). The white blood cell count fell dramatically after the exchange, and the rate of rise was slower after exchange therapy compared with preexchange. T he constellation of bronchopneumonia, extreme leukocytosis, refractory hypoxemia, and pulmonary hypertension (PHT) is well described in severe Bordetella pertussis infection in infants. 1,2 The onset of refractory hypoxemia typically is rapid 3,4 and responds poorly to advanced ventilation maneuvers, including high-frequency oscillatory ventilation, inhaled nitric oxide, and extracorporeal life support (ECLS). 5,6 The mechanism of hypoxemia and pulmonary hypertension in this setting is undetermined; however, several lines of evidence support leukocyte thrombi as the cause. White blood cell (WBC) counts Ͼ100 000 in the setting of B pertussis pneumonia are associated with increased mortality. 7,8 A leukocyte thrombus in a pulmonary venule has been reported in a fatal case of B pertussis pneumonia. 3 Finally, respiratory distress has been described in adults and children with hyperleukocytosis secondary to leukemia. 9,10 In the last setting, respiratory distress has resolved after the application of techniques to reduce the leukocyte mass, including leukopheresis and exchange transfusion. We postulated that the application of a similar strategy to reduce leukocyte mass in the setting of B pertussis pneumonia, hypoxemia, and PHT may prevent additional thrombi formation and allow resolution of preexisting thrombi. We report the first use of a double volume exchange transfusion as a therapy for B pertussis pneumonia with PHT and hypoxemia and describe the improvements in oxygenation temporally associated with that therapy. CASE REPORTSA 3-month-old, 5-kg, white girl had been seen 3 times in the 16 days before admission for cough and rhinitis. She was prescribed albuterol and a 2-day course of prednisone when she first became ill, and nebulized albuterol was prescribed at 2 subsequent visits, all with minimal improvement. The patient was seen by her primary care physician and admitted to a local hospital with mild respiratory distress. Her physical examination was remarkable for temperature 101.1°F, heart rate 176 beats/min, respiratory rate 60 breaths/min, and oxygen saturation 96% with the fraction of inspired oxygen (Fio 2 ) 0.27. Lung examination was significant for rales in all fields with a congested, "hackin...

A dilated cardiomyopathy locus (designated CMD1G) is located on chromosome 2q31 and causes early-onset congestive heart failure. Although titin remains an intriguing candidate gene for this disorder, a disease-causing mutation is not present in its cardiac-specific N2-B domain.

The 11q terminal deletion disorder or Jacobsen syndrome is a contiguous gene disorder. It is characterized by psychomotor retardation, cardiac defects, blood dyscrasias (Paris-Trousseau syndrome) and craniofacial anomalies. We report on a female patient with an approximately 10 Mb interstitial deletion with many of the features of Jacobsen syndrome: A congenital heart defect, dysmorphic features, developmental delay, and Paris-Trousseau syndrome. The karyotype of the patient is 46,XX,del(11)(q24.1q24.3). The interstitial deletion was confirmed using FISH probes for distal 11q, and the breakpoints were characterized by microarray analysis. This is the first molecularly characterized interstitial deletion in a patient with the clinical features of Jacobsen syndrome. The deletion includes FLI-1, but not JAM-3, which will help to determine the critical genes involved in this syndrome.