Title : Hemophagocytic lymphohistiocytosis syndrome and syndrome of inappropriate antidiuretic hormone ADH release: keep in mind visceral leishmaniasis. Case report and literature review
Introduction. Visceral leishmaniasis is an potentially fatal and neglected tropical disease, according to the World Health Organization’s : mortality is still very high ( 95% ) when untreated. This disease presents a broad spectrum of symptoms (oligosymptomatic infection, but also life-threatening chronic condition). Shorter (≤30 days) diagnostic delay and treatment completion are associated with less mortality.
Case report and Literature review. We present the case of a 72-year-old woman came to our observation for asthenia, episodes of confusion, fever, liver function derangement, hyperferritinemia, biological inflammation syndrome, pancytopenia resulted secondary to hemophagocytic lymphohistiocytosis and severe hyponatremia. HS score 141. Anamnesis was positive just for dysmetabolic syndrome (overweight, diabetes mellitus II, hypertensive heart disease). Abdominal ultrasound showed hepatosplenomegaly. Our diagnostic hypotheses were: a dysmetabolic liver disease with secondary splenomegaly due to portal hypertension, a splenomegaly due to haematological aetiology (rare blasts in peripheral blood), an infectious hepatosplenomegaly. An hypercortisolism was present.
The case was characterized by two points:
- A severe hyponatremia associated to hypo-osmolality in normovolemic patient, resulted secondary to Syndrome of inappropriate ADH secretion (SIADH) . A sensitive search on Pubmed (Mesh term ‘Hyponatremia’ and ‘visceral leishmaniasis’) shows only 6 analogous cases.
- A Hemophagocytic lymphohistiocytosis syndrome . In this context, the Leishmania PCR from peripheral blood and bone marrow was positive, negative serology for toxoplasma, HIV, CMV, EBV, Parvovirus, HZV, HHV 6-8. A sensitive search on Pubmed (Key-words ‘Hyponatremia’ and ‘visceral leishmaniasis’) shows other 43 anlaogous cases (limits: ‘adults’). The patient was treated with Amphotericin with progressive clinical remission
-The pathogenesis of hyponatremia in Leishmaniasis is very complex and is associated to several hemodynamic and hormonal factors (reduced body water, especially if present vomiting, diarrhea and dehydration associated to vasopressin release, as well as renin-angiotensin-aldosterone system activation, renal Na+ loss, tubular dysfunction, polyclonal activation of B lymphocytes with secondary pseudo hyponatremia). SIADH in Leihsmaniasis most likely derives from the intense inflammatory response associated to activation of hypothalamic-pituitary axis and antidiuretic hormone release
-Hemophagocytic lymphohistiocytosis syndrome is more common associated to malignancy and infection. Mortality is 29% in study cohort and so it should be considered a lethal disease.
-It is important to keep in mind a leismaniasis etiology in the presence of these 2 conditions, to clearly improve the prognosis of patients.