[Lymphomas in immunocompromised patients].

Immunosuppression is a well known risk factor for the development of lymphoid pathologies. The classification of these neoplasias is becoming more precise and complex, some features being common to all immunocompromised patients, primarily the important influence of Epstein-Barr virus. Whatever the origin of the immunodepression, these lymphoid proliferations are very heterogeneous, constituting a wide range between polymorphic aspects and clearly lymphomatous morphologies indistinguishable from those observed in immunocompetent subjects.

[Diagnostic workup in front of an adult monocytosis].

The discovery of a monocytosis is a frequent phenomenon, requiring confirmation by reading under a microscope by an experimented biologist, to overcome usual cytological traps such as the presence of hairy cells, promonocytes or monoblasts. In the vast majority of cases the secondary origin is very easily found by the context and/or the presence of a biological inflammatory syndrome. More rarely the diagnosis is directed towards an eosinophilic pathology or an acute leukemia.

[Monoclonal gammopathy of undetermined significance (MGUS): interpretative shades of analysis and sometimes serious clinical consequences].

The etiological assessment of a monoclonal gammopathy is currently standardized, the decisional algorithms allowing a sufficiently precise classification to consider the care, wait or therapeutic. The purpose of this review is to recall the difficulties concerning the interpretation of certain biological investigations and to point out the potential complications of monoclonal gammopathies labeled as "benign". The cooperation between clinicians and biologists is in all cases essential, allowing to propose on a case-by-case basis the best adapted explorations.

Diagnostic workup in front of an adult neutropenia.

Adult neutropenia, defined as a blood neutrophil count below 1.5 G/L, is a common condition. The most common cause of acute neutropenia is a drug-related reaction or an acute infectious disease.

[How I do in front of an hemolytic anemia of unknown etiology?].

The most frequent causes of hemolytic anemias are immune or infectious diseases, drug induced hemolysis, thrombotic microangiopathies, hereditary spherocytosis, glucose-6-phosphate dehydrogenase or pyruvate kinase deficiencies, thalassemia's and sickle cell disease. Sometimes no cause is found because a rarer etiology is involved. The goal of this review is to remember some unfrequent constitutional or acquired causes and to point out difficulties to avoid wrong interpretations of analysis results.

Quasispecies variant dynamics during emergence of resistance to raltegravir in HIV-1-infected patients.

Objectives: Raltegravir is the first approved inhibitor of HIV-1 integrase (IN). In most patients, raltegravir failure is associated with mutations in the IN gene, through two different genetic pathways: 155 (N155H) or 148 (Q148K/R/H). The objective of this study was to characterize the dynamics of HIV-1 quasispecies variant populations in patients who failed to respond to raltegravir treatment.