Fatal Hemophagocytic Fatal Hemophagocytic Syndrome Related to Human Syndrome Related to Human Herpesvirus-6 Reinfection Herpesvirus-6 Reinfection Following Liver Following Liver Transplantation: A Case Transplantation: A Case ReportReport

Case report:Case report: A 49y old woman underwent liver-kidney transplant in A 49y old woman underwent liver-kidney transplant in

07/2005 for polycystic liver kidney disease, resulting in CRF 07/2005 for polycystic liver kidney disease, resulting in CRF and PHTN due to venous outflow obstruction. and PHTN due to venous outflow obstruction.

Primary immunosuppression : induction with basiliximab (20 Primary immunosuppression : induction with basiliximab (20 mg on D0 and D4), & steroids (pred 10 mg/kg/d for 3 days, mg on D0 and D4), & steroids (pred 10 mg/kg/d for 3 days, then 20 mg/d), MMF (500 mg tid), and cyclosporine (250 mg then 20 mg/d), MMF (500 mg tid), and cyclosporine (250 mg bid). bid).

Graft functionwas satisfactory and, Graft functionwas satisfactory and, Liver graft biopsy showed slight steatosis, with no ischemia-Liver graft biopsy showed slight steatosis, with no ischemia-

reperfusion damage. reperfusion damage. On day 12: Sudden fever 38°C and extensive skin rash. On day 12: Sudden fever 38°C and extensive skin rash. No pathogen was found, and chest X ray was normal. No pathogen was found, and chest X ray was normal. All bacterial, fungal and viralAll bacterial, fungal and viral screenings were neg., & CMV screenings were neg., & CMV

antigen was undetectable.antigen was undetectable.

Clinical progress:….Clinical progress:….

Empiric broad-spectrum antibiotics were administered. Empiric broad-spectrum antibiotics were administered. The clinical condition deteriorated with neurological s/s The clinical condition deteriorated with neurological s/s

with confusion and lung infiltrates with severe hypoxemia with confusion and lung infiltrates with severe hypoxemia requiring mechanical ventilation. requiring mechanical ventilation.

On day 19, leukopenia and thrombopenia, with liver On day 19, leukopenia and thrombopenia, with liver dysfunction, severe hyponatremia at 112 mEq/L. dysfunction, severe hyponatremia at 112 mEq/L.

A bone marrow biopsy showed erythro- and A bone marrow biopsy showed erythro- and thrombophagocytosis leading to the diagnosis of thrombophagocytosis leading to the diagnosis of hemophagocytic syndrome. hemophagocytic syndrome.

The patient died on postoperative day 23.The patient died on postoperative day 23.

Autopsy findings:Autopsy findings:

At autopsy the spleen, bone marrow, and liver showed At autopsy the spleen, bone marrow, and liver showed numerous activated macrophages engulfing erythrocytes and numerous activated macrophages engulfing erythrocytes and leukocytes, without lymphoid malignancy.leukocytes, without lymphoid malignancy.

Serum samples were subject to HHV-6 polymerase chain Serum samples were subject to HHV-6 polymerase chain reaction (PCR): & showed negative results prior to reaction (PCR): & showed negative results prior to transplantation and in the early postoperative period (day 9 transplantation and in the early postoperative period (day 9 after LT), after LT),

: and the viral load was at 21,254 copies/g of DNA on day 20. : and the viral load was at 21,254 copies/g of DNA on day 20. Serological analysis showed positivity for IgG before Serological analysis showed positivity for IgG before

transplantation, proving the existence of a previous infection. transplantation, proving the existence of a previous infection.

Hemophagocytosis in liver and bone marrow:Hemophagocytosis in liver and bone marrow:phagocytosis by macrophages of erythrocytes and phagocytosis by macrophages of erythrocytes and leukocytesleukocytes

About HHV-6:-About HHV-6:- HHV-6 causes HHV-6 causes exanthema subitum (roseola infantum),

febrile seizures and other infectious syndromes of earlyof early childhood. Adults have a high sero-prevalence of 90-95% childhood. Adults have a high sero-prevalence of 90-95% and primary infections are uncommon. and primary infections are uncommon.

Two variants of HHV-6 exist: HHV-6A and HHV-6B.Two variants of HHV-6 exist: HHV-6A and HHV-6B. After first infection, HHV-6 persists for life, being shed in After first infection, HHV-6 persists for life, being shed in

saliva and transmitted to others, and may reactivate during saliva and transmitted to others, and may reactivate during immunosuppression.immunosuppression.

HHV-6 is ubiquitous in humans, >95% of adults being HHV-6 is ubiquitous in humans, >95% of adults being seropositive. The geographic differences in HHV-6 seropositive. The geographic differences in HHV-6 prevalence vary between 70 and 100%. HHV-6 infects prevalence vary between 70 and 100%. HHV-6 infects over 90% of people within the first two years of life.over 90% of people within the first two years of life.

Most HHV-6 infections are asymptomatic or very mild, Most HHV-6 infections are asymptomatic or very mild, and about 80% of them without any clinical symptoms.and about 80% of them without any clinical symptoms.

HE-stained sections of HE-stained sections of cervical lymph node from a cervical lymph node from a patient. patient. Paracortical areas containing Paracortical areas containing a population of atypical cells. a population of atypical cells. Many of the cells contain Many of the cells contain large, eosinophilic, nuclear, large, eosinophilic, nuclear, and/or cytoplasmic inclusions, and/or cytoplasmic inclusions, suggesting viral etiology. suggesting viral etiology. Immunostaining for HHV-6 Immunostaining for HHV-6 revels numerous positive revels numerous positive atypical cells. Cytoplasmic atypical cells. Cytoplasmic inclusions are positive.inclusions are positive. Immunohistochemical stains Immunohistochemical stains reveal that atypical cells, reveal that atypical cells, including cells with inclusions including cells with inclusions (arrows), are positive for CD3 (arrows), are positive for CD3 and CD4. and CD4. H&E-stained section of the H&E-stained section of the liver biopsy from a patient liver biopsy from a patient demonstrating viral demonstrating viral inclusions. inclusions.

HHV-6 in TransplantationHHV-6 in Transplantation It is generally agreed that most adult transplant recipients It is generally agreed that most adult transplant recipients

are seropositive for HHV-6 prior to transplant.are seropositive for HHV-6 prior to transplant.

HHV-6 reactivates approximately 50% of the patients HHV-6 reactivates approximately 50% of the patients relatively early after transplant, i.e. during the first 2 to 4 relatively early after transplant, i.e. during the first 2 to 4 weeks after transplant.weeks after transplant.

Clinical manifestations of HHV-6 infections in these Clinical manifestations of HHV-6 infections in these patients are not subject to such a clear consensus……….. patients are not subject to such a clear consensus……….. Some investigators have concluded that the HHV-6 Some investigators have concluded that the HHV-6 reactivations cause significant clinical disease (bone reactivations cause significant clinical disease (bone marrow suppression and CNS disease), while other authors marrow suppression and CNS disease), while other authors have failed to observe such disease associations. The have failed to observe such disease associations. The severity of disease varies along the whole spectrum from severity of disease varies along the whole spectrum from mild febrile illness, leukopenia to fulminant encephalitis.mild febrile illness, leukopenia to fulminant encephalitis.

It has been shown that 20% to 40% of liver transplant It has been shown that 20% to 40% of liver transplant recipients develop active HHV-6 infection. recipients develop active HHV-6 infection.

Virus is usually detected in the absence of clinical Virus is usually detected in the absence of clinical manifestations or organ involvement; although when manifestations or organ involvement; although when symptomatic, clinical conditions include fever, bone symptomatic, clinical conditions include fever, bone marrow suppression, and skin rash.marrow suppression, and skin rash.

After SOT, HHV-6 has been associated with poorer After SOT, HHV-6 has been associated with poorer outcomes [encephalitis, other infections including CMV, outcomes [encephalitis, other infections including CMV, rejection and mortality].rejection and mortality].

However the exact pathogenesis of HHV-6 remains to However the exact pathogenesis of HHV-6 remains to be defined. (HHV-6 is known to be lymphotrophic and be defined. (HHV-6 is known to be lymphotrophic and neurotrophic, with the ability to infect a multitude of cell neurotrophic, with the ability to infect a multitude of cell types).types).

HHV-6 in solid organ transplants:HHV-6 in solid organ transplants: In prospectively studied liver transplant patients, 50% In prospectively studied liver transplant patients, 50%

were positive for HHV-6 infection by virus isolation from were positive for HHV-6 infection by virus isolation from blood within 5 weeks of transplant, and 60% of these virus blood within 5 weeks of transplant, and 60% of these virus positive patients showed concurrent fever, 40% showed positive patients showed concurrent fever, 40% showed associated thrombocytopenia, and 20% developed associated thrombocytopenia, and 20% developed associated mental status changes associated mental status changes (N Singh et al)(N Singh et al). .

In a more extensive prospective study of liver transplant In a more extensive prospective study of liver transplant patients patients (Chang FY, 1999)(Chang FY, 1999), HHV-6 reactivations , HHV-6 reactivations accounted for 80% of the cases of idiopathic leukopenia accounted for 80% of the cases of idiopathic leukopenia and were the predominant cause of febrile illnesses after and were the predominant cause of febrile illnesses after transplant. transplant.

Data suggests that the incidence of HHV-6 associated Data suggests that the incidence of HHV-6 associated disease ranges from approximately 30% to 60% in patients disease ranges from approximately 30% to 60% in patients who are actively viremic, an incidence similar to that who are actively viremic, an incidence similar to that observed with CMV observed with CMV (Meyers et al)(Meyers et al)..

Time-related appearance of HHV-6, HHV-7 and CMV Time-related appearance of HHV-6, HHV-7 and CMV antigenemia:antigenemia:

The problem:…..The problem:…..

There is still uncertainty as to the precise role that this There is still uncertainty as to the precise role that this virus plays in causing the associated clinical outcomes virus plays in causing the associated clinical outcomes following transplantation. This uncertainty exists due to following transplantation. This uncertainty exists due to the persistent nature of HHV-6 infection.the persistent nature of HHV-6 infection.

HHV-6 infections cause fever, bone marrow suppression HHV-6 infections cause fever, bone marrow suppression (esp in bone marrow transplants) and CNS disease in (esp in bone marrow transplants) and CNS disease in both BMT and solid organ transplant patients.both BMT and solid organ transplant patients.

Data is complicated by the facts that different types of Data is complicated by the facts that different types of transplant recipients vary widely with respect to their transplant recipients vary widely with respect to their degree of immuno-suppression, that transplantation degree of immuno-suppression, that transplantation protocols vary between different programs and protocols vary between different programs and institutions, and that different diagnostic procedures have institutions, and that different diagnostic procedures have been applied to patient samplesbeen applied to patient samples

HHV-6 infection in transplant patients is usually asymptomatic but HHV-6 infection in transplant patients is usually asymptomatic but complications have also been reported. HHV-6 may cause fever and complications have also been reported. HHV-6 may cause fever and other symptoms, neurological disorders, graft dysfunction, other symptoms, neurological disorders, graft dysfunction, pneumonitis and hepatitispneumonitis and hepatitis (Herbein, 1996, Humar, 2002, Lautenschlager, (Herbein, 1996, Humar, 2002, Lautenschlager,

1998, Ljungman,2000, Singh, 1997, Yoshikawa, 2002, Zerr , 2001)1998, Ljungman,2000, Singh, 1997, Yoshikawa, 2002, Zerr , 2001). . Indirect effects also have been recorded. HHV-6 is considered an Indirect effects also have been recorded. HHV-6 is considered an

immunomodulatory virus that may facilitate superinfections with immunomodulatory virus that may facilitate superinfections with other opportunistic infectionsother opportunistic infections (Flamand et al. 1995, Singh et al. 1997)(Flamand et al. 1995, Singh et al. 1997). . HHV-6 reactivations are often associated with rejections and CMV HHV-6 reactivations are often associated with rejections and CMV infectionsinfections (Dockrell et al. 1997, Griffiths et al. 1999, Lautenschlager et al. (Dockrell et al. 1997, Griffiths et al. 1999, Lautenschlager et al.

1998)1998). . No guidelines have been identified for HHV-6 infection.No guidelines have been identified for HHV-6 infection. Hemophagocytic syndrome: disorder of immune regulation, Hemophagocytic syndrome: disorder of immune regulation,

characterized by a widespread proliferation and multisystemic characterized by a widespread proliferation and multisystemic infiltration of macrophages that result in uncontrolled infiltration of macrophages that result in uncontrolled hemophagocytosis in bone marrow and/or reticulo-endothelial hemophagocytosis in bone marrow and/or reticulo-endothelial system, and hence cytopenias.system, and hence cytopenias.

Diagnosis:Diagnosis: Current serologic tests are based on either Current serologic tests are based on either

immunofluorescenceimmunofluorescence or enzyme immunoassays, andor enzyme immunoassays, and are are not adequately sensitive or specificnot adequately sensitive or specific

Antigenic cross-reactivity between HHV-6 andAntigenic cross-reactivity between HHV-6 and CMV CMV remains unclear .remains unclear .

The virus often cannot be isolatedThe virus often cannot be isolated from PBMCs. The poor from PBMCs. The poor results of cultures for HHV-6results of cultures for HHV-6 could reflect the scarcity of could reflect the scarcity of active viral replication in mostactive viral replication in most subjects, which would make subjects, which would make its detection more clinically meaningful.its detection more clinically meaningful.

PCR isPCR is more sensitive than culture for the detection of more sensitive than culture for the detection of HHV-6. HHV-6.

Quantitative PCR may help define the border between Quantitative PCR may help define the border between latency and active virallatency and active viral replication. replication.

The use of monoclonal antibodies and nucleic acid probes The use of monoclonal antibodies and nucleic acid probes forfor in situ detection will probably yield new information of in situ detection will probably yield new information of substantialsubstantial medical interest.medical interest.

Treatment:Treatment:

Gancyclovir.Gancyclovir. Foscarnet.Foscarnet. Cidofovir.Cidofovir.

Thus…Thus…

A high index of suspicion would be critical.A high index of suspicion would be critical. All patients with All patients with

- skin rash.- skin rash.

- leukopenia/ unexplained cytopenia.- leukopenia/ unexplained cytopenia.

- CNS signs and symptoms/ convulsions.- CNS signs and symptoms/ convulsions.

- unexplained fever.- unexplained fever.

should be screened for HHV-6 infection.should be screened for HHV-6 infection. Isolation of the virus from cell free fluids; and Isolation of the virus from cell free fluids; and

quantitative PCR on peripheral blood mononuclear cells quantitative PCR on peripheral blood mononuclear cells are representative of active infection.are representative of active infection.

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