The fetoplacental interface plays a unique role in pathologies of the fetus and neonate, and is increasingly being recognized for effects on fetal and neonatal development that resonate into adulthood. In this review, we will use several exemplary disorders involving each of the 3 types of blood cells to explore the effect of perinatal insults on subsequent development of the affected cell line. We will present new data regarding outcomes of infants treated prenatally for fetal and neonatal alloimmune thrombocytopenia (FNAIT) and contrast these with outcomes of infants affected by hemolytic disease of the fetus and newborn. We also will explore the differences between FNAIT and passively transferred antibodies, as seen in maternal idiopathic thrombocytopenic purpura. Neonatal hemochromatosis is an example of a disease that previously was largely fatal, but whose newly discovered etiology as an immune-mediated perinatal disorder has resulted in development of highly effective treatment. Finally, we will examine the interplay between lymphopoiesis and the placenta in an effort to further explore the phenomenon of neutropenia in preeclampsia, whose etiology remains unknown.

Of 59 adults admitted to Bellevue Hospital, New York, between 1968 and 1979 because of hypothermia due to exposure, 24 (41%) had 32 serious infections. Nine infections were not diagnosed at the time of admission. Infected patients warmed to higher peak temperatures were more likely to be comatose and had lower lymphocyte counts. At admission, physicians gave antibiotics to only one of nine patients with occult infection but to ten of 35 uninfected patients, thus failing to identify which patients required prompt antibiotic therapy. Delay in therapy contributed to the death of two patients. Since infection is frequently masked in hypothermic patients, careful repeated evaluations should be carried out to identify early infections. Although the proper use of antibiotics in patients with hypothermia is unresolved, we believe that prompt empiric antibiotic therapy is appropriate.

Rickettsialpox is a mild illness characterized by the appearance of a primary eschar at the site of a mite bite followed by fever, headache, and a papulovesicular rash. It can be confused with a variety of illnesses including several other rickettsial diseases and chickenpox. R. akari, the etiologic agent, is a rickettsia belonging to the spotted fever group (SFG) of rickettsial illnesses. In spite of significant serologic cross-reactivity with other SFG agents, there is no convincing evidence of cross-immunity to these agents after recovery from rickettsialpox. Tetracyclinie is the drug of choice in the treatment of this disease.

In two previously well nonsmokers fatal pneumonia developed with extensive abscess formation. Legionnaires' bacillus was the only pathogen isolated. These cases indicate that Legionnaires' bacillus is capable of causing extensive necrosis of the lung.