Mehdi Farhangi

Lysozymuria and renal tubular dysfunction in monocytic and myelomonocytic leukemia

Abstract Monocytic or myelomonocytic leukemia is associated with lysozymuria. These patients often also have hypokalemia. In order to determine whether or not there is an association between lysozymuria and hypokalemia, balance studies were performed in three patients with this disorder and hypokalemia. The results indicate that all three patients had marked lysozymuria and inappropriately high rates of renal potassium loss. There was also limitation in titratable acid excretion in one patient and glycosuria and hyperuricosuria in another. Ammonium excretion following the administration of an ammonium chloride load was above the expected values at a given urine pH in two patients. All subjects had osteoporosis and fractures developed spontaneously or following minor trauma.

Myeloma with Xanthoderma Due to an IgGλ Monoclonal Anti-Flavin Antibody

Abstract When yellow skin and yellow hair developed in an elderly patient with multiple myeloma, we ruled out the usual causes of such pigmentation but identified a monoclonal LgGλ (LgGGar) with anti-flavin antibody activity. Purified LgGGar was brightyellow, and the acid-dissociated chromophore was identified as riboflavin by chromatography and absorption spectroscopy. Native LgGGar contained 1.45 moles of flavin per mole of IgG, and increased to 2 moles with addition of riboflavin to saturation. The flavin was localized to the Fab fragment and was bound to LgGGar with high affinity. LgGGar showed strongest affinities for riboflavin, flavin mononucleotide and flavin adenine dinucleotide, and lower affinities for dinitrophenyl derivatives and naphthoquinone. The demonstration of hapten bound to the circulating monoclonal immunoglobulin in this case suggests the possibility of bound but colorless haptens on other myeloma proteins as well as on normal immunoglobulins (N Engl J Med 294:177–183, 1976)

Severe leukocytosis with neutrophilia (leukemoid reaction) in alcoholic steatohepatitis

colitis was unremarkable, and the patient did not appear to have predisposing factors for ischemic colitis. Although I agree with the cautious conclusion that Aeromonasmay have been responsible for their patient’s illness, several points would appear to merit further comment. As the authors suggest, the patient’s presentation was typical of ischemic colitis, on both a clinical and colonoscopic basis. Also, the distribution of segmental colitis was consistent (and rather typical) of an ischemic colitic event, with involvement of the “watershed” area. The authors state that mesenteric angiography was unremarkable. Unfortunately, this does not exclude the possibility of ischemic colitis, which is now considered to be a spontaneous event, without major mesenteric vessel occlusion ( i.e., events are believed to be “low-flow” and nonocclusive in nature) (2). Lastly, lack of “predisposing” or precipitating factors does not exclude the possibility of ischemic colitis, as although many conditions have been associated with this disorder, no such factor is identified in the majority of patients (3). In conclusion, although Aeromonasmay have been responsible for this patient’s illness, one must remain vigilant as to a possible ischemic etiology, which cannot be excluded, despite the apparent vigor of the authors’ evaluation.

Biology, Clinical Patterns, and Treatment of Multiple Myeloma and Related Plasma–Cell Dyscrasias

The common denominator in ail plasma–cell dyscrasias (PCDs) is the inordinate expansion of differentiated B–cell clones (plasma cells) capable of synthesis and secretion of immunoglobulin (Ig) or its subunits. The structurally homogeneous secreted proteins can be demonstrated in the serum and urine of the overwhelming majority of patients. In only rare instances can no secreted product be demonstrated, and infrequently, two or more clones can be shown to occur simultaneously (see Section 4.1.10f).

Pathogenic role of a monoclonal IgA (κ) anti-IgG paraprotein associated with hemorrhagic diathesis, rheumatoid arthritis, vascular purpura, and acute membranoproliferative glomerulonephritis

Sixteen years earlier a 42-year-old woman with an IgA κ plasma cell neoplasm presented with bleeding disorder. Her prolonged course was complicated by subsequent development of rheumatoid arthritis, vascular purpura, and an acute membranoproliferative glomerulonephritis (MPGN). The paraprotein and its (Fab′)2 fragment showed affinity for a test myeloma IgG2 (λ) paraprotein. The patients serum and the IgA-IgG complex separated by gel filtration did not exhibit cryoprecipitation. The complex also did not dissociate by ultracentrifugation. Electron microscopic and immunofluorescent studies of a renal biopsy sample taken during the episode of nephritis showed subendothelial deposits and a lacy fluorescent pattern strongly positive for IgA and IgG. The same immunoglobulins were eluted from the kidney at postmortem. A low concentration of monoclonal IgA κ (antibody) and excess unbound polyclonal IgG (antigen) were demonstrated in the patients serum at the time of MPGN, apparently analogous to the conditions necessary for the induction of experimental immune complex nephritis.