Bisalbuminemia en un paciente con un cáncer de pulmón diseminado / Bisalbuminemia in a patient with metastatic lung cancer

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[Dysalbuminemia]. / Les dysalbuminémies.

Albumin is the major circulating protein. It plays a fundamental role maintaining intra-vascular oncotic pressure and carrying many endogenous and exogenous substances. Variations of plasma albumin levels can be physiologic or pathologic and both qualitative and quantitative (more frequent) disorders are regrouped under the name "dysalbuminemia". Although hypoalbuminemia are frequent, analbuminemia exists but is a rare disease. Qualitative disorders, mainly bisalbuminemia, are benign. Detected fortuitously on sera protein electrophoresis, bisalbuminemia could be genetically transmitted, it will then be permanent, or acquired and then be transient. This article proposes to review main kind of dysalbuminemia usually encountered in clinical biology laboratories.

[Congenital atransferrinemia]. / Kongenitale Atransferrinämie.

Congenital atransferrinemia was first diagnosed at the age of 11 months in a now 27-year-old woman. Until she was aged 14 years treatment with human transferrin was irregular and, as it turned out, inadequate. But since then she has regularly received human transferrin (1 g monthly) and deferoxamine (500 mg twice weekly). Despite this she developed haemosiderosis affecting heart, liver, hypophysis, thyroid and the locomotor apparatus. This case report demonstrates the need of early diagnosis and treatment of congenital atransferrinemia to prevent the mentioned complications.

Fibrinogen Baltimore III: congenital dysfibrinogenemia with a shortened gamma-subunit.

An abnormal fibrinogen has been found in an asymptomatic Negro female. Clinical laboratory findings were normal, except for a prolonged thrombin time which was corrected by addition of calcium. Fibrinopeptide release by thrombin and crosslinking by factor XIII also occurred normally, but fibrin monomer polymerization was delayed. Sodium dodecylsulfate-polyacrylamide gel electrophoresis disclosed that 50% of the gamma-subunits migrated with an apparent Mr of 45,500, approximately 1,500 Da smaller than normal. The evidence suggests that an internal sequence of 10-15 residues is missing from the gamma-subunit of the abnormal fibrinogen.

The molecular abnormality of albumin Parklands: 365 Asp----His.

An electrophoretically slow albumin variant was isolated from the plasma of a patient with bisalbuminemia. Reverse-phase peptide mapping revealed a single altered peak when tryptic digests of the normal and variant albumin were compared. After rechromatography and amino acid analysis, a sequence/composition of Cys-Cys-Ala-Ala-Ala-His-Pro,His,Glu,Cys,Tyr,Ala,Lys was obtained for the mutant peptide, while a sequence of Cys-Cys-Ala-Ala-Ala-Asp-Pro-His-Glu-Cys-Tyr,Ala,Lys was obtained for the normal peptide. This establishes the mutation as 365 Asp----His and the new albumin has been named albumin Parklands. Interestingly, this mutation results in the loss of the single Asp-Pro bond that is normally present between residues 365 and 366. Predictably, this confers on albumin Parklands a greater resistance to partial acid hydrolysis, a feature which, when employed together with SDS-gel electrophoresis, can be used as a diagnostic test for the presence of this variant.

Studies of an abnormal serum albumin unstable upon storage.

A case of inherited bisalbuminemia was discovered in which electrophoretic controls showed that the proportion of the abnormal albumin decreased progressively during storage of the serum either at 4 degrees C or at room temperature. Such a decrease was also found when the serum was incubated with the proteolytic enzymes trypsin or plasmin. Studies with the isolated abnormal albumin showed that either during storage or after incubation with trypsin (or plasmin), its mobility became identical to that of normal serum albumin. Structural analyses showed that the albumin variant was identical to the previously described pro-albumin Christchurch that contains an additional N-terminal sequence: Arg-Gly-Val-Phe-Arg-Gln. It was therefore suggested that the progressive decrease of the abnormal albumin during storage by serum was related to the cleavage of the N-terminal abnormal sequence by plasmin already present in the serum. The decrease of the abnormal albumin during storage was inhibited by addition of cortisol to serum (1 mol per mol serum albumin). This was found related to a protective effect of cortisol bound to the albumin variant on proteolysis by plasmin.

[Study of bisalbuminemias of the "fast" type]. / Contributo allo studio delle bisalbuminemie di tipo "fast".

A case of alloalbuminaemia of the fast type was described in a family living in the district of Pesaro. This was one of the few cases of this particular type and the first observed in this region. Being related to electrophoretic mobility, it is classified as: very fast, type gent. This anomaly has been evidenced by electrophoresis on cellulose acetate, while immunoelectrophoresis with an anti-protein total serum does not reveal the immunological differences referred to in normal albumine.

[Bisalbuminemia (author's transl)]. / Les bisalbuminémies.

After a review of first two causes of bisalbuminemia: genetic mutation and overdosage during antibiotherapy with beta-lactamines, the authors underline the importance of searching for a bisalbuminemia during the course of pancreatic disease or when confronted with a serous collection, particularly an ascite of undetermined origin. Effectively, the finding of a bisalbuminemia in these two circumstances, after having eliminated the first two etiologies, permits the confirmation of the diagnostic of a pancreatic fistula. This diagnostic should imply exploratory surgery, even without other confirmation, and a per-op. wirsungography if the fistula is not visible macroscopically. The surgical correction of the fistula cures the patient and the bisalbuminemia disappears in several hours.

Glycosylated minor components of human fetal hemoglobin. Chromatographic separation, identification, and functional characterization.

Human adult red cell lysate contains glycosylated minor hemoglobins AIa1, AIa2, AIb, and AIc. Similar minor hemoglobins, designated FIa1, FIa2, Fib, and FIc, have been separated by a Biorex 70 column chromatographic procedure from red cell lysates of newborn children and from an adult homozygote for hereditary persistence of fetal Hb. The minor Hb components were characterized by analyzing for carbohydrate and phosphate contents, by oxygen equilibrium analysis, and by comparing the chromatographic elution profiles of naturally occurring and in vitro synthesized minor components. The results indicate that Hb FIa1, Hb FIa2, and Hb FIc have been formed by the modification of gamma chains of Hb F by reacting with fructose-1,6-P2, glucose-6-P, and glucose, respectively. Hb FIb is a glycoprotein; the mechanism of its formation is unclear. Hb FIa1 and Hb FIa2 had significantly lower oxygen affinities and n values than the other minor components and the major Hb F0. Moreover, 2,3-diphosphoglycerate did not influence the oxygenation of the minor or the major fetal Hb components. Incubations of Hb F with [14C]hexoses and subsequent chromatographic separation of hemoglobins and their globin chains confirm the previous findings that the binding of carbohydrate to Hb involves both specific and nonspecific reactions.