The immunity features and defects against primary cytomegalovirus infection post-splenectomy indicate an immunocompromised status

Abstract

Background:To evaluate if splenectomy results in severely impaired immune responses against primary cytomegalovirus (CMV) infection compared to the general immunocompetent population.Methods:We performed a systemic literature review to study CMV infections in splenectomized individuals, a special population group presently considered immunocompetent to viral infections. We retrieved 30 cases with established CMV infection post-splenectomy and we recorded their disease manifestations, laboratory findings, immunological studies, and histopathology reports. In addition, we retrieved numerous multidisciplinary articles in view of post-splenectomy immunology defects, as well as of immune responses to primary invading CMV in the absence of the spleen. Two clinical studies directly comparing splenectomized with nonsplenectomized individuals under severe iatrogenic immunosuppression as well as the numerically largest review articles of CMV infections in immunocompetent were retained.Results:Splenectomy results in the loss of spleen's ability to fend-off blood-borne pathogens and impairs the link between innate and adaptive immunity. The major post-splenectomy immune-defects against CMV are: weakened, delayed or absent anti-CMV IgM, and compensatory marked IgG response; severely impaired B-cell and CD4+, CD8+ T-cells function responses; and post-splenectomy, bone marrow compensates for the absence of spleen's immune responses against CMV, mimicking a monoclonal T-cell lymphoproliferative process.Conclusion:The puzzled diagnosis of the CMV syndrome post-splenectomy is of the most challenging and misleading, resulting in risky and costly interventions and a subsequent prolonged hospitalization (2 months). The mounting multi-disciplinary literature evidence renders us to suggest that splenectomized individuals are not only prone to encapsulated bacteria but also behave as immunocompromised to CMV.

Challenges in diagnosing post-splenectomy cytomegalovirus mononucleosis

“…The infection can also be transmitted through sexual contact, blood transfusions and organ transplants [ 1 ] . CMV infection can occur as a primary infection (without prior infection), reinfection or reactivation [ 2 , 4 ] . The virus remains dormant in the host’s body and can reactivate from time to time [ 1 ] , depending on the patient’s immune status.…”

“…The virus remains dormant in the host’s body and can reactivate from time to time [ 1 ] , depending on the patient’s immune status. Critically ill patients with AIDS, bone marrow transplants or haematological cancers are at higher risk of reactivation [ 4 ] . Previous studies with primary CMV infection and individuals who have undergone splenectomy noted a prevailing pattern of a history of blood transfusion in such cases [ 4 , 6 ] .…”

“…Critically ill patients with AIDS, bone marrow transplants or haematological cancers are at higher risk of reactivation [ 4 ] . Previous studies with primary CMV infection and individuals who have undergone splenectomy noted a prevailing pattern of a history of blood transfusion in such cases [ 4 , 6 ] . Consistently, our patient who underwent splenectomy surgery also disclosed a history of blood transfusion.…”

“…In a meta-analysis regarding CMV diagnosis post-splenectomy, most cases were diagnosed based upon serology alone (33%), or in a combination with other methods (67%) [ 4 ] . Some studies have demonstrated that most patients have weakly positive or negative IgM (50%) and strong IgG (38%) [ 4 ] . However, histopathology demonstrating the CMV antigen and cytopathogenic changes in tissue specimens remains the reference standard for the diagnosis of tissue-invasive CMV disease [ 9 ] , but this is not commonly done due to invasiveness of the procedure.…”

“…In most cases, people who are not immunocompromised do not experience any symptoms [ 1 , 3 ] because their immune system keeps the virus under control [ 2 ] . However, those who have weakened immune systems, such as people living with HIV, transplant recipients and infants infected during pregnancy, are highly susceptible to the virus [ 1 , 4 ] . In such cases, CMV can replicate uncontrollably, leading to viremia, dissemination to multiple organs and end-organ diseases [ 2 ] .…”