Aplastic anemia following varicella vaccine.

Varicella zoster vaccine is a safe vaccine that is rarely associated with life-threatening complications. We describe an immunocompetent child who developed transient severe aplastic anemia concomitant with a typical clinical and laboratory-proven chickenpox syndrome 3 weeks after immunization. A causative association between the vaccine and the hematologic disease is possible, and pediatricians should be aware of this severe although rare adverse event.

Neurologic abnormalities in patients with adenosine deaminase deficiency.

Defects in adenosine deaminase enzyme cause severe immunodeficiency. Without enzyme replacement or allogeneic bone marrow transplantation, patients often suffer fatal infection in infancy. Adenosine deaminase is expressed ubiquitously; deficiency may affect various organs, including the brain. Neurologic abnormalities occur in some adenosine deaminase-deficient patients, mostly in association with infection or after bone marrow transplantation. Three cases with significant neurologic abnormalities, including hypotonia, head lag, nystagmus, difficulty in focusing gaze, seizure disorder, and moderate-severe developmental delay but with no evidence of infection or transplant-related medication toxicity are presented. Computed tomographic scans and cranial MRI revealed volume loss and abnormalities of basal ganglia and thalamus, which may reflect accelerated nerve cell death or altered stimulation of adenosine receptors. Detailed neurologic and neuroimaging evaluation should be performed for all patients with adenosine deaminase deficiency upon diagnosis, to identify potentially significant brain lesions.

Thrombocytopenia in Kawasaki disease: a risk factor for the development of coronary artery aneurysms.

The authors report on a 2-year-old boy with atypical Kawasaki disease (KD) and thrombocytopenia who developed 3 coronary artery aneurysms. The mechanism of thrombocytopenia in KD seems to be consumption coagulopathy. Review of the 30 reported cases of KD and thrombocytopenia revealed that this combination is more common in girls and in young age groups, and is associated with an increased risk of coronary artery aneurysm and myocardial infarction.

[The severity and prolonged morbidity of community acquired pneumonia caused by group A Streptococcus].

We describe a case report of a sixteen year old patient who was admitted with severe group A streptococcal (GAS) pleuro-pneumonia, underwent pleurocentesis and recovered after two weeks of hospitalization, although complete recovery lasted for another three weeks. The present publication aims to highlight the severe, prolonged and complicated course of GAS pneumonia in children which has not yet been reported in Israel. Accurate diagnosis is crucial for appropriate therapy, which is a prolonged i.v. course of penicillin.

Enhancement of pentylenetetrazole-induced seizures by Shigella dysenteriae in LPS-resistant C3H/HeJ mice: role of the host response.

Convulsions and encephalopathy are common complications of Shiga toxin (Stx)-producing Shigella and enterohemorrhagic Escherichia coli infections. In previous studies, we demonstrated that Stx and lipopolysaccharide (LPS) act in concert to enhance mice sensitivity to pentylenetetrazole (PTZ)-induced seizures via mechanisms involving tumor necrosis factor alpha (TNFalpha), interleukinl beta and nitric oxide. To further elucidate the role of the host response in Shigella-related seizures, we studied the ability of Shigella dysenteriae and its products to modulate seizures in C3H/HeJ (lps(d/d)) and in C3H/HeN (lps(n/n) mice. Injection of S. dysenteriae 60R sonicate elevated plasma TNFalpha and enhanced the convulsive response to PTZ in both mouse strains. Induced TNFalpha levels were markedly lower in LPS-hyporesponsive C3H/HeJ mice than in LPS- responsive C3H/HeN mice: 7.4 ng/ml vs 44 ng/ml (induced by 4LD50). Accordingly, a higher dose of S. dysenteriae sonicate was needed to sensitize the C3H/HeJ mice to seizures. Stx or LPS alone did not enhance seizures in either strain. Stx together with LPS enhanced seizures in LPS-responsive mice, but not in LPS-hyporesponsive mice in which they induced only a minor elevation in TNFalpha levels (1.5 ng/ml). As compared to LPS-responsive mice, the LPS-hyporesponsive mice were less susceptible to the lethal effects of Shigella sonicate and were resistant to the lethal effect of purified Stx with LPS. These results demonstrate the crucial role of the host response with regard to the sensitivity to to LPS, and specifically TNFalpha production, in Shigella lethality and Shigella-related seizures.