Haemoglobin J-Baltimore can be detected by HbA1c electropherogram but with underestimated HbA1c value.

Glycated haemoglobin (HbA(1c)) is considered the gold standard for assessing diabetes compensation and treatment. In addition, fortuitous detection of haemoglobin variants during HbA1c measurement is not rare. Recently, two publications reported different conclusions on accuracy of HbA(1c) value using capillary electrophoresis method in presence of haemoglobin J-Baltimore (HbJ).Here we describe the fortuitous detection of unknown HbJ using capillary electrophoresis for measurement of HbA(1c). A patient followed for gestational diabetes in our laboratory presented unknown haemoglobin on Capillarys 2 Flex Piercing analyser which was identified as HbJ. HbJ is not associated with haematological abnormalities. High Performance Liquid Chromatography methods are known to possibly underestimate HbA(1c) value in the presence of this variant. This variant and its glycated form are clearly distinguished on electropherogram but HbJ was responsible for underestimating the true area of HbA(1c). Capillary electrophoresis is a good method for detecting HbJ but does not seem suitable for evaluation of HbA(1C) value in patients in presence of HbJ variant.

A diabetic case with hemoglobin J-Meerut and low HbA1C levels.

A diabetic patient with hemoglobin (Hb) J-Meerut and low HbA1C levels is reported. An automatic glycohemoglobin analyzer used for the determination of HbA1C revealed an abnormal peak of the peripheral blood obtained from a Japanese female with diabetes. She showed a lower HbA1C level (3.7%) than expected from her fasting plasma glucose (172 mg/dl). High performance liquid chromatography and isoelectric focusing indicated that her abnormal hemoglobin was Hb J-Meerut [alpha 120(H3)Ala-->Glu] and it accounted for 28.3% of the total hemoglobin. Abnormal hemoglobinemia should be considered when a major discrepancy between the levels of HbA1C and fasting plasma glucose is observed.

Identification of Hb J-Sardegna [alpha 50(CE8)His----Asp] by HPLC and its incidence in northern Sardinia.

As many as 7,717 babies born consecutively and 3,412 blood donors of Sardinian ancestry have been examined for the detection of the Hb J-Sardegna variant [alpha 50(CE8)His----Asp]; all subjects were from Northern Sardinia. Hemolysates were analyzed by isoelectricfocusing and the identification of the variant was made by reversed phase high performance liquid chromatography of the tryptic peptides. A total of 28 carriers (1:397) of Hb J-Sardegna were identified. The incidence of 0.25% makes this hemoglobin one of the most common alpha-globin structural mutants in humans. The distribution of the anomaly appears to be nonhomogeneous in the island. The quantity of the variant ranged from 19 to 36%; this wide range probably reflects the co-inheritance of an alpha-thalassemia anomaly.

A new unstable and low oxygen affinity hemoglobin variant: Hb J-Auckland [beta 25(B7)Gly----Asp].

Hb J-Auckland is a new hemoglobin variant with the amino acid substitution beta 25(B7)Gly----Asp. It is mildly unstable and has a low oxygen affinity. The propositus and a son, both heterozygous for Hb J-Auckland, have marginally low Hb values but no apparent clinical symptoms.

Hemoglobin J Iran alpha 2 beta 2 77 (EF1) his----Asp in a Russian-Armenian family.

A third case of Hb J Iran is reported. The propositus is of Russian-Armenian origin and was investigated for hematuria. The electrophoretic behavior and the characterization of primary structure are described. Hb J Iran is stable and has normal functional properties. High resolution Nuclear Magnetic Resonance spectra suggest the presence of structural perturbations in the heme pocket of the variant. Solubility studies of Hb S/Hb J Iran mixture indicated that His beta 77 belongs to a contact region of deoxy Hb S polymers.

A new case of hemoglobin Providence (alpha 2 beta 2 82 (EF6) Lys----Asn or Asp) discovered in a French Caucasian family. Structural and functional studies.

A new case of Hb Providence was discovered in a French caucasian family presenting a mild polycythemia. Structural and functional studies of the two abnormal fractions (Hb Providence Asn and Asp) have been performed. These confirm the abnormal characteristics of Hb Providence described previously. Red cells containing Hb Providence were fractionated with a Percoll Albumin density gradient. The respective amounts of the two components were determined in the youngest and oldest cells. We observed a slight increase of Hb Providence Asp from 34 to 37% during the life span of the erythrocytes which confirms that the deamidation of Hb Providence Asn to Hb Providence Asp is a fast process, already present and close to its maximum, in the reticulocytes. Both abnormal components are stable in the presence of isopropanol.

Hb J Camaguey alpha 2 141(HC3) Arg replaced by Gly beta 2: a new abnormal human hemoglobin.

An electrophoretic fast-moving hemoglobin was found in a Cuban family of Spanish descent. Structural studies demonstrated a replacement of arginine by glycine at alpha 141(HC3). This change is not associated with clinical symptoms, although the substitution is in one of the residues involved in the stabilization of the deoxy form of the hemoglobin molecule.

Separation of human hemoglobins by DEAE-cellulose chromatography using glycine-KCN-NaC1 developers.

This chromatographic procedure uses DEAE-cellulose as ion exchanger and glycine-KCN-NaC1 solutions as developers. Blood samples from several adults and newborn infants with alpha, beta, delta, or gamma chains variants have been analysed. The hemoglobins are eluted as compact and symmetrical zones, and the separation of many hemoglobin types is greatly improved. The procedure is relatively fast, simple, and inexpensive.