A haemophagocytic lymphohistiocytosis (HLH)-like picture following breastmilk transmitted cytomegalovirus infection in a preterm infant

Management of neonatal central nervous system viral infections: Knowledge gaps and research priorities

Congenital CMV, enteroviruses, human parechovirus and herpes simplex virus are all common causes of severe central nervous system (CNS) infection in neonates. The introduction of screening (i.e. newborn hearing screening programme), integration of molecular syndromic testing (i.e. multiplex polymerase chain reaction assays) and increase in sexually transmitted infections (i.e. anogenital herpes) have contributed to increases in each of these infections over the last decade. However, therapeutic options are highly limited in part due to the lack of epidemiological data informing trials. This review will describe our current understanding of the clinical burden and epidemiology of these severe neonatal CNS infections, outline the novel antiviral and vaccines in the pipeline and suggest future research studies which could help develop new therapeutics.

Cytomegalovirus-Induced Hemophagocytic Lymphohistiocytosis in an Extreme Preterm Infant: Recognition and Therapy Leading to Recovery

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rare disease that can be triggered by cytomegalovirus, a relatively common infectious exposure to neonates. The clinical presentation is common to many acute illnesses seen in extreme premature infants; however, there are key clinical and laboratory findings that can lead to the diagnosis.

PURPOSE

We present a case of an extreme premature infant of 25 weeks' gestation who developed cytomegalovirus-induced HLH. Using the current published protocols that are used in pediatric cancer can be adapted for use in a premature infant, which led to remission of HLH and eventual discharge from the neonatal intensive care unit.

IMPLICATIONS FOR PRACTICE

There are published treatment protocols used in pediatric oncology that when initiated early can lead to favorable outcomes and remission in even the most fragile neonates.

IMPLICATIONS FOR RESEARCH

Additional studies are needed on the pharmacokinetics, dosing, and side effects on medications used for treatment of HLH in preterm infants. Additional research is needed to improve the clinician's ability to reach the diagnosis as well as define treatment strategies that provide optimal outcomes.

Secondary haemophagocytic lymphohistiocytosis triggered by postnatally acquired cytomegalovirus infection in a late preterm infant

Haemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory condition with impairment of cytotoxic T-cells and natural killer cells. Causes in infants are mostly hereditary immune defects as well as various infectious triggering factors, amongst these cytomegalovirus (CMV). Vertical CMV transmission may occur in utero, during birth, and by breast feeding. Usually, a CMV infection transmitted via breast milk is symptomatic only in very immature preterm infants. We report on a late preterm infant born after 35 + 5 weeks of gestation with a birth weight of 1840 g, being admitted to our intensive care unit at the age of 9 weeks with acute enteritis and severe dehydration. After a prolonged recovery, the infant developed a sepsis-like condition with hyperpyrexia, hepatosplenomegaly, and pancytopenia. Combination with high ferritin levels (2809 μg/l), hypertriglyceridaemia (481 mg/dl), elevated soluble IL-2 receptor (sCD25, 9120 U/ml), and reduced perforin expression allowed diagnosis of HLH, caused by an acute CMV infection. Since connatal CMV infection had been ruled out earlier, we report the rare case of secondary HLH triggered by a postnatally acquired symptomatic CMV infection in an immunocompetent infant, most likely transmitted via breast milk. The infant was successfully treated with ganciclovir without need for immunosuppressive therapy.

Anti-viral therapy for congenital cytomegalovirus infection: pharmacokinetics, efficacy and side effects

Congenital cytomegalovirus (CMV) infection is the most common congenital infection in the world with approximately 0.5-2% of all live born infants, and can cause early or late severe neurological and neurisensorial damage. Although no drug has been licensed for therapy of congenital CMV infection, ganciclovir (GCV) and its oral pro-drug, valganciclovir (val-GCV), is increasingly being administrated to symptomatic infants, to improve neurodevelopmental and auditory outcome. Other potentially efficacious for therapy of congenital CMV disease are foscarnet and cidofovir, which have only been administered in few cases. A literature search was performed to look for evidence based or scientific articles evaluating pharmacokinetics, efficacy, and side effects of GCV/val-GCVand the other two anti-viral drugs.

Safety of alternative antiviral agents for neonatal herpes simplex virus encephalitis and disseminated infection

OBJECTIVE

To review the evidence describing the safety of ganciclovir and foscarnet in neonates in order to guide treatment for central nervous system or disseminated herpes simplex infections in cases of acyclovir shortage or resistance.

METHODS

PubMed, Ovid Medline, and International Pharmaceutical Abstracts were searched using the thesaurus and text-word terms "ganciclovir" and "foscarnet," with birth to 1 month age limits. Thirty-two eligible publications describing safety in neonates were identified.

RESULTS

In 340 neonates treated for cytomegalovirus (CMV), life-threatening neutropenia (absolute neutrophil count <0.5 × 10(9)/L) was reported in 8.8% of patients following up to 12 months of ganciclovir administered intravenously. Neutropenia and thrombocytopenia occurred in 25.6% and 6.2% of neonates, respectively. Changes in serum creatinine concentration of >0.2 mg/dL occurred in <1% of neonates. Hepatic transaminase increases or unspecified changes in liver function tests were reported in 6.2% of neonates with hyperbilirubinemia being observed in 3.5% of total neonates. Three out of four neonates receiving foscarnet for acyclovir-resistant herpes infection or CMV survived with minimal sequelae. Neither nephrotoxicity nor electrolyte or mineral imbalances were reported.

CONCLUSIONS

Similar to what is seen in adolescents and adults, ganciclovir use in neonates is commonly associated with neutropenia, and the frequency of occurrence is comparable. The link between hepatotoxicity and ganciclovir should be interpreted with caution because of overlapping clinical manifestations of CMV. Only case reports are available describing foscarnet use in neonates, but adverse drug reactions were not observed. More research on these two agents is needed to draw conclusions about adverse drug reaction rates in the neonatal population.

Hemophagocytic lymphohistiocytosis associated with cytomegalovirus infection in an immunocompetent infant: a diagnostic and therapeutic challenge!

Hemophagocytic lymphohistiocytosis (HLH) is a potentially fatal syndrome that results from inappropriate activation of the immune system. Many viral agents are known to trigger HLH but cytomegalovirus (CMV) associated HLH is rarely described. We report a case of CMV related HLH in a 3½ month old immunocompetent male infant who presented with fever, respiratory distress and hepatosplenomegaly. He had fulminant sepsis like course in the hospital as he continued to have hectic fever spikes, progressive pneumonia, increasing hepatosplenomegaly and multiple episodes of generalized convulsions. Investigations revealed bicytopenia, biochemical hepatitis, hyperferritinemia and hypofibrinogenemia. CMV IgM serology was reactive in both infant and mother. Diagnosis of CMV-HLH was made as per HLH 2004 diagnostic protocol. Infant was successfully treated with intravenous ganciclovir along with dexamethasone and etoposide.

Transmission of cytomegalovirus via breast milk to the prematurely born infant: a systematic review

To analyse current data on transmission of human cytomegalovirus (HCMV) via breast milk with subsequent symptomatic HCMV infection of the preterm infant and to report on long-term follow-up, a systematic literature review was performed using EMBASE, MEDLINE and CINAHL (January 1966 to December 2008) Studies were included for analysis if congenital HCMV infection was excluded and transmission via breast milk was either confirmed or strongly suspected. Twenty-six studies were included for analysis. Maternal HCMV-IgG-positivity was reported to be in the range 51.6-100% (median 81.6%), HCMV-IgG detection in breast milk in the range 67-97.2% (median 80%) and HCMV-positivity of the infants in the range 5.7-58.6%. Symptomatic HCMV disease occurred in 0-34.5% (median 3.7%) and severe sepsis-like syndrome in 0-13.8% (median 0.7%). Data on long-term outcome of preterm infants with symptomatic HCMV infection revealed a low risk for mild neurological and cognitive sequelae, without hearing impairment. Recommendations for high-risk preterm infants diverged markedly. The current data report low rates of symptomatic disease after transmission of HCMV via breast milk to the preterm infant without evidence of certain long-term sequelae. The results of our review do not support a general approach, either by avoidance or pasteurization of breast milk, in high-risk preterm infants.

[Review and guidelines on the prevention, diagnosis and treatment of post-natal cytomegalovirus infection]

Postnatal cytomegalovirus (CMV) infection in the newborn can occur from exposure to maternal cervical secretions during birth, ingestion of breast milk, transfusion of blood products or transmission by body fluids of infected people. Breast milk is the main source of infection, given the high rate of CMV-positive mothers excreting CMV in milk. Freezing reduces the risk of CMV transmission by breastfeeding, although it does not eliminate it completely. Pasteurisation prevents such transmission, but it can alter the immunological properties of breast milk. Postnatal CMV infection is usually asymptomatic, as it normally results from viral reactivation in the mother, and the neonate is born with protective antibodies. However, in the very low birth weight premature infant the amount of transferred antibodies is smaller and a symptomatic infection can occur. Symptomatic post-natal CMV infection in the newborn typically causes hepatitis, neutropenia, thrombocytopenia or sepsis-like syndrome. Pneumonitis and enteritis are less common, but very characteristic. Diagnosis is based on urine virus detection at the time of onset of symptoms. Postnatal CMV infection in the newborn generally resolves spontaneously without antiviral treatment. Ganciclovir should be reserved for severe cases. Unlike congenital CMV disease, post-natal CMV infection in the preterm infant does not seem to be associated with hearing loss or abnormal neuro-development in long term follow-up.

Hemophagocytic lymphohistiocytosis and other hemophagocytic disorders

Hemophagocytic disorders result when critical regulatory pathways responsible for the natural termination of immune/inflammatory responses are disrupted or overwhelmed. Hemophagocytic disorders reflect pathologic defects that alter the normal crosstalk between innate and adaptive immune responses, and compromise homeostatic removal of cells that are superfluous or dangerous to the organism. Although hemophagocytic disorders are considered rare, increased awareness of these conditions has led to more frequent diagnoses, more rapid initiation of life-saving treatments, and new insights into the molecules and pathways involved in natural immune down-regulation. Furthermore, improved understanding of the immunologic abnormalities revealed by hemophagocytic disorders informs potential new treatments for life-threatening multisystem organ dysfunction related to sepsis in the intensive care unit setting and severe cases.

Cytomegalovirus transmission to preterm infants during lactation

Breastfeeding has a major impact on HCMV epidemiology. The incidence of postnatal HCMV reactivation during lactation equals the maternal seroprevalence. Infectious virus, viral DNA and RNA can be isolated easily from cell and fat-free milk whey. Early onset of viral DNAlactia and virolactia as well as high viral load in milk whey are maternal risk factors for virus transmission. The dynamics of HCMV reactivation can be described by unimodal kinetics with interindividual variation. Virus reactivation during lactation is a self-limiting local process in the absence of systemic HCMV infection. Preterm infants below 1000g birthweight and a gestational age below 30 weeks may be at high risk of acquiring a symptomatic HCMV infection. Several recent studies described low transmission rates and mostly asymptomatically infected neonates using frozen milk. Despite different freeze-storing procedures, HCMV transmissions occurred, and severe HCMV infections were observed. Few data exist on the long-term outcome of postnatally acquired HCMV infection via breast milk. To substantiate the international debate on the use of native or inactivated milk for feeding of preterm infants, additional data are necessary for better identification of mother-infant-pairs at risk for viral transmission and symptomatic infection early after birth.