Disseminated Mycobacterium avium-intracellulare infection in a patient with myelodysplastic syndrome (refractory anemia)

Infections in myelodysplastic syndromes

Myelodysplastic syndromes are associated with a risk of severe infections. While neutropenia is likely to be the main predisposing factor, several other immune defects have been reported, including impaired neutrophil function, B-, T- and NK-cell defects and the possible consequences of iron overload due to red blood cell transfusions. The advanced age of most patients, their frequent comorbidities, and the fact that drugs such as hypomethylating agents and lenalidomide, which are effective in myelodysplastic syndromes but can transiently worsen neutropenia, may increase the risk of infection and their severity in this context. The majority of infections in myelodysplastic syndromes are bacterial, while the incidence of fungal infections is not well known and viral infections seem to be rare. No prophylactic measures against infections have demonstrated efficacy in myelodysplastic syndromes. However, pending more data, we propose here some recommendations for the management of patients with myelodysplastic syndromes. In the future, an important contribution can be made by prospective trials testing the efficacy of prophylactic and therapeutic approaches to infection in these patients, especially in the context of the new drugs available for myelodysplastic syndromes.

Cutaneous infectious granuloma caused by Phenylobacterium in an adult with myelodysplastic syndrome: a first case report

Painful granulomatous lesions appeared on the face of a 36-year-old man with myelodysplastic syndrome. Skin biopsy revealed chronic inflammatory granuloma. Bacterial cultures of the lesions and blood indicated the same unknown Gram-negative rod bacterium. The 16S ribosomal RNA sequence of the unknown bacterium yielded Phenylobacterium. Thus, we diagnosed cutaneous infectious granuloma caused by Phenylobacterium and myelodysplastic syndrome/refractory cytopenia with multi-lineage dysplasia. After treatment with combined antibacterials that were selected based on the tests for drug sensitivity, the lesions disappeared with only scars remaining and without any signs of relapse after 1 year. This is the first case report of cutaneous infectious granuloma caused by Phenylobacterium.

Sibling cases of Mycobacterium avium complex disease associated with hematological disease

A 22-year-old man who was admitted to our respiratory division complaining of fever and cough of 1 month's duration had been diagnosed with myelodysplastic syndrome 5 years earlier. On admission, radiological findings showed bilateral diffuse small nodular shadows. Although the results of an acid-fast bacilli examination of blood, sputum, and urine samples were all negative, we initiated antituberculous therapy for suspected miliary tuberculosis because the histological diagnosis from a bone marrow biopsy was epitheloid granuloma. The abnormalities on his chest radiographs improved, but his left cervical lymph nodes became swollen. The histological result of a lymph node biopsy revealed epitheloid granuloma with caseating necrosis. The DNA-DNA hybridization result of a resected lymph node culture indicated Mycobacterium avium. The final diagnosis was disseminated Mycobacterium avium complex (MAC) disease. Both leukocytopenia and thrombocytopenia had been noted in the patient's 19-year-old younger brother, who had been living in the same home 5 years earlier, and for whom a diagnosis of myelodysplastic syndrome was made from bone marrow aspiration on admission. An infiltration shadow with nodular shadows was noted in the right upper lung field on a chest radiograph. A bronchoscopic examination revealed pulmonary MAC disease. As for the route of infection, although we investigated restriction fragment length polymorphism (RFLP), a different pattern was found in the two brothers. We suspect that they were infected by different species of Mycobacterium avium in the same environment rather than by droplet infection from the younger brother to the older brother.

A family inheriting different subtypes of acute myelogenous leukemia

Rare inherited cancer syndromes have proven invaluable for the identification of genes involved in the more frequent corresponding noninherited cases. We report on a family with an adult onset, incompletely penetrant, autosomal dominant syndrome of myelodysplasia and acute myelogenous leukemia, affecting at least eight, and probably ten, individuals from three generations. The patients have developed leukemias differing in morphologic subtype, tumor cytogenetics, and abruptness of presentation. Some have presented with acute onset and others with protracted myelodysplasia. This family does not have an unusual incidence of other malignancies; however, one person at 50% risk of inheriting this gene developed atypical mycobacterium infection in the absence of leukemia, but also without appreciable risk factors for acquired deficiencies in cellular immunity. Features common to affected family members, including the individual with mycobacterium infection, are the early presence in the bone marrow of red cell and platelet maturation defects. A search for mutations in diseased marrows fails to detect abnormalities of p53 or N-ras. Two of the affected family members, third degree relatives, have co-inherited a constitutional chromosomal banding variation of 9p21-22, potentially suggesting linkage to this locus. The variable penetrance and expressivity of this syndrome support a multistep model of leukemia evolution, in which the gene defined by this family's syndrome is the signal step.