Saiprakash B. Venkateshiah

Sleep-Disordered Breathing During Pregnancy

Pregnancy is associated with many physiologic and hormonal changes along with changes in sleep architecture, placing pregnant women at risk for the development of sleep-disordered breathing or worsening of preexisting sleep apnea. Snoring, the most common symptom of sleep-disordered breathing, is markedly increased during pregnancy. The exact prevalence of obstructive sleep apnea in pregnant women is unknown. Because the apneic episodes are commonly associated with oxyhemoglobin desaturations, the combination of obstructive sleep apnea and pregnancy can be potentially harmful to the fetus given the low oxygen reserves during pregnancy. Obstructive sleep apnea has been associated with an increased risk of hypertension among the general population, and this raises the possibility of its association with gestational hypertension and preeclampsia. In this clinical review, we discuss the physiologic changes of pregnancy that predispose pregnant women to the development of obstructive sleep apnea and the effects of sleep-disordered breathing on pregnancy outcomes. We also review the recommendations regarding evaluation for sleep apnea and treatment options during pregnancy and postpartum.

Pulmonary Alveolar Proteinosis

Pulmonary alveolar proteinosis (PAP) is characterized by the accumulation of surfactant phospholipids and proteins within the lung alveoli. Important advances have been made over the past 8 years in our understanding of this disease, offering new directions for research and patient care. First, genetically altered mice that are homozygous for a disrupted granulocyte-macrophage colony-stimulating factor (GM-CSF) gene developed a lung lesion with histologic resemblance to PAP. The surfactant is thought to be catabolized or cleared mostly by alveolar macrophages, this process being dependent on GM-CSF. Second, a neutralizing autoantibody against GM-CSF was found in serum and bronchoalveolar lavage fluid of patients with idiopathic PAP but not in healthy controls, thereby raising the suspicion that human PAP may be an autoimmune disease. The relationship between the antibody and disease pathogenesis remains unclear but data suggest that the GM-CSF antibody may have a potential role as a diagnostic test.No specific therapy exists for PAP. Sequential whole lung lavage is the standard of care. Exogenous therapy with GM-CSF may improve the lung disease in some patients with PAP but this therapy is still experimental. Interventions directed at treating a relative GM-CSF deficiency by administration of GM-CSF or lowering the antibody level (i.e. by plasmapheresis or immunosuppression) may hold promise as future therapy for this rare disease.