Observational study of cytomegalovirus from breast milk and necrotising enterocolitis

OBJECTIVE

To evaluate the relationship between cytomegalovirus (CMV) exposure from breast milk and risk of necrotising enterocolitis (NEC).

DESIGN

Secondary analysis of a multicentre, observational cohort study. Maternal breast milk and infant serum or urine were serially evaluated by nucleic acid testing at scheduled intervals for CMV. Infants with evidence of congenital infection were excluded. Competing-risks Cox models, with adjustment for confounders, were used to evaluate the relationship between breast milk CMV exposure or postnatal CMV infection and NEC.

SETTING

Three neonatal intensive care units in Atlanta, Georgia.

PATIENTS

Infants with a birth weight≤1500 grams.

EXPOSURES

Maximal CMV viral load in breast milk in the first 14 days after birth or postnatal CMV infection. Two different approaches were used to assess the timing of onset of CMV infection (midpoint or early).

MAIN OUTCOME MEASURES

NEC, defined as Bell stage II or greater.

RESULTS

Among 596 enrolled infants, 457 (77%) were born to CMV seropositive mothers and 33 developed postnatal CMV infection (cumulative incidence 7.3%, 95% CI 5.0% to 10.1%). The incidence of NEC was 18% (6/33) among infants with CMV infection, compared with 7% (37/563) among infants without infection (adjusted cause-specific HR (CSHR): 2.81; 95% CI 0.73 to 10.9 (midpoint); 6.02; 95% CI 1.28 to 28.4 (early)). Exposure to higher breast milk CMV viral load was associated with a higher risk of NEC (adjusted CSHR per twofold increase 1.28; 95% CI 1.06 to 1.54).

CONCLUSIONS

CMV exposure from breast milk may be associated with the development of NEC in very low birth weight infants.

Long-term stability of CMV DNA in human breast milk

BACKGROUND

Human cytomegalovirus (CMV) is the leading cause of intrauterine and perinatal viral infection. The most common route of CMV transmission in newborns is through breastmilk and this can lead to infant morbidity and mortality. Breast milk that has been frozen for an extended period may need to be tested for CMV DNA to determine the source of infection. It has been a challenge for clinical laboratories to ensure the stability of CMV DNA in frozen breast milk for accurate viral load measurement.

OBJECTIVES

To evaluate the stability of CMV DNA in breast milk by testing quantitative viral loads over a 28-day period for breast milk stored at 4 °C and a 90-day period for breast milk stored at -20 °C.

STUDY DESIGN

Baseline viral loads were determined on day 0 and the samples stored at 4 °C underwent extraction and amplification at four time points, up to 28 days. The samples stored at -20 °C underwent extraction and amplification at five time points up to 90 days. Log₁₀ values were calculated and t-test, Pearson's coefficient, and concordance correlation coefficient were calculated.

RESULTS

There was no statistically significant difference between the time points by t-test, and correlation coefficients showed greater than 90% concordance for days 0 and 28 as well as days 0 and 90 at both storage temperatures tested.

CONCLUSIONS

The concentration of CMV DNA in breast milk was stable for 28 days at 4 °C and 90 days at -20 °C as the concentrations did not differ significantly from the baseline viral loads.

Platelet Transfusion Practices Among Very-Low-Birth-Weight Infants

IMPORTANCE

Thrombocytopenia and intraventricular hemorrhage (IVH) are common among very-low-birth-weight (VLBW) infants. Survey results suggest that US neonatologists frequently administer platelet transfusions to VLBW infants with mild to moderate thrombocytopenia.

OBJECTIVES

To characterize platelet transfusion practices in US neonatal intensive care units (NICUs), to determine whether severity of illness influences platelet transfusion decisions, and to examine the association between platelet count (PCT) and the risk for IVH in the first 7 days of life.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, retrospective cohort study included 972 VLBW infants treated in 6 US NICUs, with admission dates from January 1, 2006, to December 31, 2007. Data were collected from all infants until NICU discharge or death (last day of data collected, December 4, 2008). Data were entered into the central database, cleaned, and analyzed from May 1, 2009, to February 11, 2016.

INTERVENTION

Platelet transfusion.

MAIN OUTCOMES AND MEASURES

Number of platelet transfusions and incidence of IVH.

RESULTS

Among the 972 VLBW infants (520 [53.5%] male; mean [SD] gestational age, 28.2 [2.9] weeks), 231 received 1002 platelet transfusions (mean [SD], 4.3 [6.0] per infant; range, 1-63 per infant). The pretransfusion PCT was at least 50 000/μL for 653 of 998 transfusions (65.4%) with this information. Two hundred eighty-one transfusions (28.0%) were given during the first 7 days of life. During that period, platelet transfusions were given on 35 of 53 days (66.0%) when the patient had a PCT less than 50 000/μL and on 203 of 436 days (46.6%) when the patient had a PCT of 50 000/μL to 99 000/μL. At least 1 marker of severe illness was present on 198 of 212 patient-days (93.4%) with thrombocytopenia (PCT, <100 000/μL) when a platelet transfusion was given compared with 113 of 190 patient-days (59.5%) with thrombocytopenia when no platelet transfusion was given. Thrombocytopenia was a risk factor for intraventricular hemorrhage during the first 7 days of life (hazard ratio, 2.17; 95% CI, 1.53-3.08; P < .001). However, no correlation was found between severity of thrombocytopenia and risk for IVH. After controlling for significant clinical factors and thrombocytopenia, platelet transfusions did not have a significant effect on the incidence of IVH (hazard ratio, 0.92; 95% CI, 0.49-1.73; P = .80).

CONCLUSIONS AND RELEVANCE

A large proportion of platelet transfusions were given to VLBW infants with PCT greater than 50 000/μL. Severity of illness influenced transfusion decisions. However, the severity of thrombocytopenia did not correlate with the risk for IVH, and platelet transfusions did not reduce this risk.

Postnatal cytomegalovirus infection: a pilot comparative effectiveness study of transfusion safety using leukoreduced-only transfusion strategy

BACKGROUND

The optimal mitigation strategy to prevent transfusion transmission of cytomegalovirus (TT-CMV) in preterm very low birthweight infants remains debated. Hospitals caring for this patient population have varied practices.

STUDY DESIGN AND METHODS

A prospective observational comparative effectiveness pilot study was conducted to determine the feasibility for a larger study. The pilot was carried out at hospitals using a leukoreduction (LR)-only transfusion strategy. Specimen and data collection for this study was performed in a similar approach to a study completed at Emory University that employed the CMV-seronegative plus LR approach. All testing was performed at one laboratory. The rates of TT-CMV using the two transfusion strategies were compared.

RESULTS

Zero incidence of TT-CMV was detected in infants (n = 20) transfused with LR-only blood (0/8; 95% confidence interval [CI], 0-25.3%) and is consistent with the previously reported zero incidence of TT-CMV finding in a cohort of infants transfused with CMV-negative plus LR blood (0/310; 95% CI, 0%-0.9%). The seroprevalence rate among enrolled mothers (n = 17) was 60%. Forty percent of those infants (8/20) received 43 transfusions; five were transfused with one or more CMV-seropositive blood components. One infant had tested positive for CMV before receiving blood transfusions; the infant's mother was CMV immunoglobulin (Ig)G positive and IgM negative.

CONCLUSIONS

Using the LR-only transfusion approach, zero cases of TT-CMV were detected in this pilot study. A larger study is needed to reliably determine the most effective strategy for prevention of TT-CMV in this population.

Cytochrome P450 2D6 polymorphisms and predicted opioid metabolism in African American children with sickle cell disease

The opioid medications codeine and hydrocodone, commonly prescribed in sickle cell disease (SCD), require metabolic conversion by cytochrome P450 2D6 (CYP2D6) to morphine and hydromorphone, respectively, to exert their analgesic effects. The CYP2D6 gene is highly polymorphic, with variant alleles that result in decreased, absent, or ultrarapid enzyme activity. Seventy-five children with SCD were tested for CYP2D6 polymorphisms, and metabolic phenotypes were inferred from the genotypes. The most common variant alleles were CYP2D6*2 (normal activity, 28.7%), CYP2D6*17 (reduced activity, 17.3%), CYP2D6*5 (gene deletion, 8.7%), and CYP2D6*4 (absent function, 8.0%). Normal/extensive metabolizer genotypes were found in 28/75 (37.5%), intermediate metabolism in 33/75 (44.0%), poor metabolism in 4/75 (5.3%), ultrarapid metabolism in 3/75 (4.0%), indeterminate in 6/75 (8.0%). Allele frequencies did not vary significantly among different hemoglobin genotypes. Identification of variant CYP2D6 genotypes may identify individuals with altered metabolism and therefore altered analgesic response to codeine and hydrocodone, thus providing a personalized medicine approach to treatment of pain in SCD. Further pharmacokinetic and pharmacodynamic studies are needed to define the relationship of CYP2D6 and other gene polymorphisms to individual opioid effect in SCD.

Distinct differences in platelet production and function between neonates and adults: implications for platelet transfusion practice

Thrombocytopenia is a common problem among sick neonates admitted to the neonatal intensive care unit. Among neonates, preterm infants are the subgroup at highest risk for thrombocytopenia and hemorrhage, which is frequently intracranial. Although there is no evidence of a relationship between platelet (PLT) count and occurrence of major hemorrhage, preterm infants are commonly transfused prophylactically when PLT counts fall below an arbitrary limit, and this threshold is usually higher than for older infants or adults. This liberal practice has been influenced by the observation that, in vitro, neonatal PLTs are hyporeactive in response to multiple agonists. However, full-term infants exhibit normal to increased primary hemostasis due to factors in neonatal blood that enhance the PLT-vessel wall interaction. Additionally, cardiorespiratory problems are considered the main etiologic factors in the development of neonatal intraventricular hemorrhage. In this review, we will discuss the developmental differences that exist in regard to PLT production and function, as well as in primary hemostasis in preterm and term neonates, and the implications of these developmental differences to transfusion medicine. PLT transfusions are not exempt of risk, and a better understanding of the PLT function and the hemostatic profile of premature infants and their changes over time and in response to illness is the starting point to design randomized controlled trials to define optimal use of PLT transfusions in premature neonates. Without these future trials, the marked disparities in PLT transfusion practice in neonates between hospitals and countries will remain over time.

A novel approach to standardised recording of bleeding in a high risk neonatal population

BACKGROUND

Bleeding assessment tools have been developed in other specialties to standardise the recording of bleeding for clinical haemostatic outcomes in transfusion trials, but such tools have not been developed for routine use in neonatology.

AIM

The objective of this study was to develop, refine and evaluate a neonatal bleeding assessment tool (NeoBAT) to standardise the clinical recording of bleeding in premature and term neonates in an intensive care setting.

METHODS

This prospective neonatal international multicentre study included all episodes of bleeding in infants admitted to the intensive/high dependency care nursery over a 2-4-week period. The NeoBAT was developed to record neonatal bleeding episodes. We tested its reliability and reproducibility with duplicate assessments.

RESULTS

Duplicate assessments revealed 98% concordance. Bleeding occurred in 25% (37/146) of infants overall and was most common in preterm infants. 11% (16/146) infants had major/severe bleeds, 1% (2/146) moderate and 13% (19/146) minor bleeds.

CONCLUSIONS

Bleeding is common in premature and term neonates admitted to intensive/high dependency care nurseries. This novel bleeding assessment tool facilitates prospective recording of bleeding events in neonatal intensive care settings and may allow standardised bleeding assessments in this high risk population.

The varicella-autoantibody syndrome

This cross-sectional study was conducted to determine the incidence of autoantibodies to phospholipids and coagulation proteins in children with acute varicella zoster virus (VZV) infection. Study groups included children with VZV alone or complicated by purpura fulminans and/or thromboembolism. VZV naïve children and children who had VZV >1 y before sample collection formed a control group. Blood was assayed for the following: free protein S (PS), protein C, antithrombin, and prothrombin; antibody binding to these proteins; lupus anticoagulant; anticardiolipin antibody; antiphospholipid antibodies; and prothrombin fragment 1+2. Data regarding coinfections was collected. Forty-three VZV-infected children showed an increased frequency of lupus anticoagulant, anticardiolipin antibody, antiphospholipid antibodies, and autoantibodies to PS, protein C, prothrombin, and antithrombin in comparison to 52 children without acute VZV (p < 0.0001). Seventeen children with VZV and purpura fulminans and/or thromboembolism showed a statistically significant decrease in free PS, significantly increased PS IgG antibody, and significantly increased prothrombin fragment 1+2 (p < 0.0001) compared with the group without acute VZV and the group with uncomplicated VZV. Twenty-six children with uncomplicated VZV showed increased PS IgG antibody (p < 0.001) compared with the children without acute VZV. For all groups combined, elevated PS IgG antibody showed negative correlation with free PS (p < 0.0001) and positive correlation with prothrombin fragment 1+2 (p = 0.0002). Autoantibodies were transient. Transient antiphospholipid and coagulation protein autoantibodies were common with VZV infection, but were not predictive of thrombotic complications.