Psittacosis-associated hemophagocytic syndrome

A fatal case of hemophagocytic lymphohistiocytosis associated with gestational psittacosis without symptoms of pneumonia

Psittacosis is a zoonotic infection caused by Chlamydia psittaci. Most patients present with acute respiratory symptoms and systemic illness. When C. psittaci infects pregnant women, it causes severe clinical manifestations called gestational psittacosis. Here we report a case of gestational psittacosis. Our patient lacked respiratory symptoms, and pathological postmortem examinations revealed severe placentitis. Both DNA and immunohistochemical analyses were positive for C. psittaci from formalin-fixed paraffin-embedded tissues. The chlamydial DNA in the placenta was about 100 times more abundant than that in the lungs; therefore, the placenta rather than the lungs was the probable target of the C. psittaci infection during this pregnancy. We could not identify the source of infection. Gestational psittacosis should be considered in the differential diagnosis for fever of unknown origin during pregnancy, even in cases lacking respiratory symptoms.

Rubella-associated hemophagocytic syndrome in an infant

Hemophagocytic syndrome (HPS) is a fulminant disorder characterized pathologically by multiple-organ infiltration of hemophagocytic histiocytes in the lymphoreticular tissues. The characteristic pathologic feature is reactive histiocytic hyperplasia with leukoerythrophagocytosis in a variety of organs. This disorder occurs most often in patients in whom the immune system is compromised and has been associated with a variety of infectious agents, including viruses, bacteria, mycobacteria, spirochetes, fungi, and parasites. The authors describe a 2.5-month-old girl with rubella-associated HPS, demonstrated by postmortem liver necropsy.

Haemophagocytic syndrome associated with infections

Haemophagocytic syndromes (HS) are the clinical manifestation of an increased macrophagic activity with haemophagocytosis. Pathophysiology is related to a deregulation of T-lymphocytes and excessive production of cytokines. The main clinicobiological features are fever, hepatosplenomegaly, adenopathies, skin rash, neurological features, cytopenias, hypertriglyceridaemia, hyperferritinaemia and coagulopathy. Diagnosis is based on examination of the bone marrow which shows benign histiocytes actively phagocytosing haemopoietic cells. Acquired HS are mostly associated with an underlying disease such as immunodeficiency, haematological neoplasias and autoimmune diseases. Infection-associated HS was originally described by Risdall in 1979, in viral disease. Since the initial description HS has also been documented in patients with bacterial, parasitic or fungal infections. Epstein-Barr virus (EBV) is the causative agent in most cases. In EBV-associated HS, which sometimes has a fatal course, unregulated T-cell reaction or uncontrolled B-cell proliferation may release cytokines. Management of HS consists of early diagnosis, careful screening for, and prompt treatment of, infections and detection and therapy of any underlying disease. Prognosis of infection-associated haemophagocytic syndrome (IAHS) is better than that in other types of secondary HS. Management of cytokine imbalance should be useful to improve the outcome and reduce the mortality rate in these cases.

Virus-associated haemophagocytic syndrome caused by rubella in an adult

Haemophagocytic syndrome is a systemic clinicopathological entity characterized by systemic proliferation of benign haemophagocytic histiocytes, fever, cytopenia, abnormal liver function and, frequently, coagulopathy and hepatosplenomegaly. Its occurrence has been documented in association with viral, bacterial, fungal and parasitic infections, a wide spectrum of malignant neoplasms, autoimmune diseases and drugs. We report a case of rubella virus-associated haemophagocytic syndrome in a previously healthy 29-year-old woman. Blood tests showed cytopenia, especially severe thrombocytopenia, liver dysfunction, hyperferritinaemia and hypercytokinaemia. Bone marrow examination showed many mature histiocytes with active haemophagocytosis. A skin biopsy from the rash revealed perivascular lymphohistiocytic infiltrates with haemophagocytic histiocytes in the upper and mid-dermis. The patient was treated with antibiotics and immunoglobulin, and by supportive measures including platelet transfusion, and recovered completely.

[Etiological aspects of reactive hemophagocytoses: retrospective study in 99 patients]

We describe the causes of reactive hemophagocytic process in a retrospective study including 99 patients. The main diagnosis were: lymphomas (18 cases), pyogenic bacteria infections (15 cases), herpes virus infections (12 cases), other infections (multiple, parasitic, fungal, mycobacterial, unidentified) (11 cases), acute hepatitis (five cases), systemic lupus erythematosus (three cases). We also found numerous other diseases involving the reticuloendothelial system. The cause remained undetermined in 16 cases. Lymphoma accounted for 64% of the cases in previously healthy patients who had been febrile for more than 10 days at the time of the diagnosis of reactive hemophagocytic process, and for 31% in HIV-positive patients. Lymphomas were rare (5%) in non HIV-positive, immunosuppressed patients. In this setting and in previously healthy patients who had been febrile for less than 10 days, infectious diseases were widely dominant (respectively 60% and 86% of the cases). Those were mainly due to pyogenic bacteria and to herpes virus. A rapidly fatal evolution occurred in some cases of lymphomas-related hemophagocytic process. These data support the choice of aggressive investigations in order to diagnose lymphoma in previously healthy patients presenting with reactive hemophagocytic process who have been febrile for more than 10 days, and in selected HIV-patients. Such a procedure is not recommended in the other cases.

Reactive hemophagocytic syndrome--a clinicopathologic study of 40 patients in an Oriental population

PURPOSE

The purpose of this investigation was to assess the clinical spectrum and outcome of reactive hemophagocytic syndrome (RHS) in an Oriental population.

PATIENTS AND METHODS

The investigation was a retrospective study of 40 consecutive patients with RHS diagnosed over a 4-year period in Queen Elizabeth Hospital, a community-based hospital in Hong Kong.

RESULTS

The incidence of RHS in Hong Kong appeared to be comparable with that of Western countries. However, the spectrum of diseases associated with RHS was distinctly different. Forty percent of the cases were associated with malignant lymphoma. Another 40% of the cases were associated with infection, often due to bacteria, and infection due to the herpes group of viruses was uncommon, probably reflecting ethnic and geographic differences from the white population. Two patients had the acute lupus hemophagocytic syndrome, a distinctive form of RHS that occurs in patients with systemic lupus erythematosus. Treatment was basically supportive, with specific therapy also given for the underlying disease if present. Eighteen patients (45%) died of the acute disease, mostly as a result of complications of RHS or the underlying diseases. The development of disseminated intravascular coagulopathy was a poor prognostic factor.

CONCLUSIONS

RHS is an uncommon disorder in Hong Kong and is often associated with malignant lymphoma or bacterial infection. A rigorous search for an underlying malignancy or infection is thus warranted once this diagnosis is made.