Thrombocytosis and hyposplenism in an infant with fetal hydantoin syndrome

Hyposplenism: A comprehensive review. Part I: Basic concepts and causes

Hyposplenism is not a rare condition and can complicate a remarkable number of illnesses. The two most time-honored diseases associated with the development of hyposplenism are sickle cell anemia and celiac disease. Hyposplenism is relatively easy to recognize by typical changes observed on the peripheral blood smear; including Howell-Jolly bodies, monocytosis, lymphocytosis, and increased platelet counts. Diagnosis can be confirmed by pitted RBC counts or 99Tc-labelled radiocolloid scan of the spleen; wherever available. Diagnosis needs to be made promptly to institute pneumococcal vaccination in a timely fashion and to recognize and treat bacterial infections promptly and aggressively because of the tendency of hyposplenic subject to develop fatal invasive disease. Overwhelming pneumococcal sepsis accounts for the major mortality cases in hyposplenic subjects; however severe infections with other encapsulated bacteria and protozoa have been reported. Hyposplenic individuals may also be at a higher risk for vascular, autoimmune and thrombotic diseases and they may have a higher risk of developing solid tumors. The commonly used pneumococcal polysaccharide vaccine is ineffective in asplenic subjects, because it requires the presence of IgM memory B cells, and should be given before splenectomy. In splenectomized, and functionally hyposplenic subjects, the pneumococcal conjugate vaccine is more effective, because it utilizes a T cell dependent mechanism, and should be the preferred vaccine in these circumstances.

Hematologic Effects of Maternal Antiretroviral Therapy and Transmission Prophylaxis in HIV-1-Exposed Uninfected Newborn Infants

OBJECTIVE

A prospective observational study to investigate hematologic alterations during the first 3 months of life in HIV-exposed uninfected infants subjected to antiretroviral medication before and after birth.

METHODS

Two hundred twenty-one consecutive uninfected infants born to HIV-positive mothers on antiretroviral medication during pregnancy were included. Perinatal transmission prophylaxis comprised zidovudine (ZDV) administered intravenously intrapartum and 10 days after birth. Blood counts and differentials were determined at birth and at 2, 4, 6, and 12 weeks of age, and hematologic toxicity was graded according to pediatric toxicity scales. Data were analyzed according to the kind of prenatal medication (ZDV alone or with another nucleoside reverse transcriptase inhibitor [NRTI] vs. highly active antiretroviral therapy [HAART]).

RESULTS

Median hemoglobin was significantly lower in HAART-exposed newborns from birth (P = 0.004) until day 28. During follow-up, 119 (53.8%) infants had anemia grade 2 or higher on at least 1 occasion; 16 (7.2%) received red blood cell transfusion at 23 (range: 1-56) days of age. Neutropenia grade 2 or higher occurred in 106 (48.0%) infants at least once; 8 infants had staphylococcal infections, and 2 infections were severe. After adjustment for possible confounders (prematurity, birth weight, ethnicity, gender, duration of maternal antiretroviral therapy, maternal Centers for Disease Control and Prevention stage, and maternal illicit drug use), HAART exposure was the only independent risk factor for anemia (odds ratio [OR] = 2.22, 95% confidence interval [CI]: 1.06 to 4.64; P = 0.034) and neutropenia (OR = 2.15, CI: 1.02 to 4.55; P = 0.045).

CONCLUSIONS

Antiretroviral transmission prophylaxis is associated with significant anemia and neutropenia in HIV-uninfected infants during the first 3 months of life. Anemia was more profound in HAART-exposed infants.