[Neurological form of onset in haemophagocytic lymphohistiocytosis]. / Forma de debut neurológico de la linfohistiocitosis hemofagocítica.

INTRODUCTION: Haemophagocyte lymphohistiocytosis (HLH) is a hematological disorder, autosomal recessive and in which there is benign proliferation of histiocytes with intense phagocytic activity of hematopoietic cells. The clinical features include fever, pancytopenia, coagulation disorders, liver dysfunction, the presence of histiocytes and haemophagocytes in the bone marrow, lymph nodes, spleen and liver. The nervous system is always involved and sooner or later patients develop a nervous system disorder with variable symptoms which may include irritability, disorders of consciousness, convulsions, ataxia, nystagmus or signs of intracranial hypertension. CLINICAL CASE: Onset of the disease showing purely neurological features is rare. We therefore describe the case of an 8 month old baby with HLH with a purely neurological condition involving irritability, horizontal rapid eye movements and vertical saccadic movements of both eyes and focal convulsive seizures. Initial complementary examinations were normal, except for study of the CSF with a lowered protein level and cells (monocytes). Finding hepatosplenomegaly and pallor, together with the laboratory investigations, made it advisable to do a bone marrow punch biopsy to detect haemophagocytes which would be diagnostic of HLH. In spite of chemotherapy there was rapid neurological deterioration, with alterations of the white matter and hydrocephaly which required insertion of a ventriculo-peritoneal shunt. The patient died when he was 10 months old. CONCLUSIONS: The cases of HLH in which cerebromeningeal disorders alone precede systemic symptoms are extremely rare. Hence the interest in reporting this case, so that it may be borne in mind in other cases of acute neurological onset. In this case initially there was encephalitis alone, but this was rapidly followed by systemic complications.

Atypical form of non-Langerhans histiocytosis with disseminated brain and leptomeningeal lesions.

An 18 year old girl presented with acute visual loss. T2 weighted brain MRI showed areas of hyperintensities in the thalamic nuclei, internal capsule, lentiform nuclei, the subarachnoidal spaces, and a retrobulbar infiltration. Analysis of CSF showed numerous foamy histiocytes without malignant cells, raised protein, and depressed glucose concentration. Biopsy of the right thalamus demonstrated aggregates of histiocytes with immunohistological and ultrastructural characteristics of non-Langerhans cell histiocytosis. The patient improved with chemotherapy and corticosteroids. After 3 months of treatment, CSF analysis showed no more histiocytes. Cytological examination of CSF can be helpful for the management of patients with extensive histiocytic infiltration.

Successful correction of hemophagocytic lymphohistiocytosis with related or unrelated bone marrow transplantation.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disorder of immune regulation leading to widespread lymphocytic and hemophagocytic infiltration of vital organs. Apparent cure has only been achieved with allogeneic bone marrow transplantation (BMT). This report describes 20 consecutive patients, who underwent either matched sibling donor (n = 4) or unrelated donor (URD; n = 16) BMT. Age at the time of BMT was 0.4 to 5.3 years (median, 0.8 years). Central nervous system disease was present at diagnosis in 13 patients. At BMT, 14 patients were in a clinical remission, whereas 6 patients had active HLH. All patients were engrafted after cytoreduction with busulfan, cyclophosphamide, and etoposide. The probability of grade II-III acute graft-versus-host disease (GVHD) for all patients was 57% (95% confidence limit [CL], 0.28, 0.86), and 73% (95% CL, 0.44, 1.0) in URD patients. The overall probability of survival at 3 years was 45% (95% CL, 0.23, 0.67) and 44% (95% CL, 0.19, 0.68) when URD BMT was evaluated separately. Favorable BMT outcome was associated with clinical remission status at the time of BMT. The preparative regimen was well tolerated, and in the 9 surviving patients it provided durable engraftment and was effective at eradicating the underlying disease.

Primary infection by HHV-6 variant B associated with a fatal case of hemophagocytic syndrome.

The association of a human herpesvirus 6 primary infection with a fatal case of hemophagocytic syndrome in a 3 month old baby is described. The trigger mechanism of the virus for the clinical syndrome is discussed.

Elevated circulating levels of interleukin-1 receptor antagonist but not IL-1 agonists in hemophagocytic lymphohistiocytosis.

The familial form of hemophagocytic lymphohistiocytosis (HLH) is an inherited disease with disturbed immunomodulation and characterized by fever, hepatosplenomegaly, cytopenia, hypertriglyceridemia, and coagulopathy, i.e., findings which are similar to many of the reported biological effects of the inflammatory cytokines. Due to the previously shown hypercytokinemia in active HLH with elevated levels of interleukin (IL)-6, tumor necrosis factor-alpha, and interferon-gamma, it has been suggested that cytokine dysregulation may be of pathophysiological importance. Here we have assayed the serum levels of the members of the IL-1 ligand family, the two agonists IL-1 alpha and IL-1 beta and the antagonist IL-1 receptor antagonist (IL-1ra), in nine children with HLH and cerebrospinal fluid (CSF) specimens from four children. Serum IL-1ra was elevated in all patients with active disease to a degree which correlated well with disease activity. Furthermore, the levels decreased day by day during treatment of a patient who suffered a relapse. Moreover, high levels of IL-1ra were also detected in CSF during active disease. However, IL-1 beta levels were all within normal limits and circulating IL-1 alpha levels were normal in all but two patients.

The cytodiagnosis of meningeal involvement in familial haemophagocytic lymphohistiocytosis.

The cytological appearances of the cerebrospinal fluid (CSF) in two cases of familial haemophagocytic lymphohistiocytosis (FHL) are described. The presence of numerous lymphocytes and immature macrophages in the CSF, some of which showed lymphohistiocytosis, was indicative of meningeal involvement. The appearance of large numbers of immature macrophages indicated rapid deterioration and death within a few weeks. Furthermore, some CSF samples taken at times when the patients were asymptomatic contained suspicious cells, indicating asymptomatic persistence of the meningeal lesions. Thus, cytological examination of CSF can assist with the management of patients with this rare disease.

Tryptophan and serotonin metabolism in familial erythrophagocytic lymphohistiocytosis.

Reduced concentrations of tryptophan and 5-hydroxyindoleacetic acid (the major CSF metabolite of serotonin) were found in the cerebrospinal fluid of two children with familial erythrophagocytic lymphohistiocytosis. This was associated with elevated cerebrospinal fluid neopterin concentrations indicating increased macrophage activity within the central nervous system. In one child, cytotoxic therapy induced a complete clinical remission and an increase of tryptophan and 5-hydroxyindoleacetic acid concentrations to normal; during a subsequent relapse, concentrations of these analytes again fell below normal. In the other child, in whom therapy produced only a transient improvement, tryptophan and 5-hydroxyindoleacetic acid concentrations remained low and the child died. It is likely that increased activity of indoleamine 2,3-dioxygenase induced by the activation of macrophages was responsible for the disturbance in serotonin and tryptophan homeostasis within the brain. Excessive tryptophan catabolism and the disturbance of serotonin turnover may play a role in the aetiology of the neurological symptoms seen in familial erythrophagocytic lymphohistiocytosis.

Central nervous system involvement in the erythrophagocytic disorders of infancy: the role of cerebrospinal fluid neopterins in their differential diagnosis and clinical management.

In two children with familial erythrophagocytic lymphohistiocytosis accompanied by neurologic symptoms, total neopterin concentrations in cerebrospinal fluid were 200 times higher than in controls and 10 to 20 times higher than in five children with presumed neurologic disease due to primary viral infections (human immunodeficiency virus, herpes simplex, measles) of the CNS. In one child with familial erythrophagocytic lymphohistiocytosis, clinical remission was accompanied by a fall in neopterin concentrations to normal; in a second child, who died, total neopterin concentrations remained high. In two other children with a diagnosis of infection-associated hemophagocytic syndrome without any neurologic disturbance, neopterin concentrations were also elevated but only to 10 times the concentrations in controls. Total neopterin concentrations in cerebrospinal fluid provide a measure of the severity of macrophage infiltration and activation within the CNS, and are useful in assessing the need for intensive chemotherapy and monitoring the response to treatment.