Keshgegian A A
Am J Clin Pathol. 1980 Sep;74(3):282-4. doi: 10.1093/ajcp/74.3.282.
The serum anion gap is often decreased in patients who have multiple myeloma or monoclonal gammopathy, presumably owing to the unmeasured contribution of cations by the paraprotein. In 83 patients who had moderate-to-severe diffuse (polyclonal) elevations in immunoglobulin concentration (> 3 g/dl), the mean serum anion gap was significantly lower than in patients who had normal concentrations of immunoglobulin. In the subgroup with immunoglobulin levels greater than 4 g/dl, the mean anion gap was 8.7 mEq/l, compared with 11.9 for the control group (P < 0.001). Known causes of decreased anion gap, such as hyperkalemia or hypercalcemia, were absent. The albumin concentration had a minimal effect on the anion gap. The mean anion gap was independent of the patient's diagnosis and the relative contribution of each immunoglobulin class to the total immunoglobulin. Thus, patients who have diffusely elevated immunoglobulin concentrations, as well as those who have monoclonal elevations, have a significantly lower mean anion gap. This low anion gap should be considered in the evaluation of the acid-base status of these patients.
多发性骨髓瘤或单克隆丙种球蛋白病患者的血清阴离子间隙通常会降低，推测是由于副蛋白对阳离子的不可测量贡献所致。在83例免疫球蛋白浓度中度至重度弥漫性（多克隆）升高（>3g/dl）的患者中，平均血清阴离子间隙显著低于免疫球蛋白浓度正常的患者。在免疫球蛋白水平大于4g/dl的亚组中，平均阴离子间隙为8.7mEq/l，而对照组为11.9（P<0.001）。不存在已知的阴离子间隙降低原因，如高钾血症或高钙血症。白蛋白浓度对阴离子间隙的影响最小。平均阴离子间隙与患者的诊断以及每种免疫球蛋白类别对总免疫球蛋白的相对贡献无关。因此，免疫球蛋白浓度弥漫性升高的患者以及单克隆升高的患者，其平均阴离子间隙显著更低。在评估这些患者的酸碱状态时应考虑到这种低阴离子间隙。
