Pseudohyperphosphatemia and dysproteinemia.

We report the case of a patient with IgG multiple myeloma and pseudohyperphosphatemia, and the case of another patient in whom unexplained hyperphosphatemia led to the diagnosis of monoclonal gammopathy. The pseudohyperphosphatemia was due to the interference of monoclonal immunoglobulins with the phosphomolybdate colorimetric assay for phosphorus determination widely in use with some automated systems. Ultrafiltration of these patients' serum samples resulted in normalization of the elevated phosphorus values. Knowledge of this phenomenon may obviate confusion, unnecessary testing, and expenditure. It may also provide clinicians with a clue as to the presence of a dysproteinemia.

Megacolon in a collagen vascular overlap syndrome.

Mixed connective tissue disease is a syndrome having clinical features of scleroderma, systemic lupus erythematosus, and polymyositis with a unique combination of clinical and laboratory findings. Not all patients with clinical features of more than one connective tissue disease fit the mixed connective disorders category; therefore, the term "overlap syndrome" is applied to patients with features of two or more connective tissue diseases. Gastrointestinal involvement in progressive systemic sclerosis is common, with the esophagus being the usual site, followed by the small bowel, colon, and stomach. Colonic involvement is reported to occur in 10 to 50 percent of cases and is typically manifested radiographically as wide-mouthed diverticular saculations. Symptoms secondary to colonic involvement are rare but occasionally serious, such as impaction of barium or feces. A case is described in which systemic lupus erythematosus coexisted with previously undiagnosed scleroderma involving predominantly the gastrointestinal tract and resulting in megacolon.

Geriatric hypertension: the growing use of calcium-channel blockers.

The recognition of essential hypertension as a heterogeneous entity mandates that therapy be individualized according to the subset of hypertension that characterizes each patient. Choosing the most appropriate therapeutic regimen in elderly hypertensives is complicated by a greater susceptibility to side effects from medications, and by concomitant diseases. Calcium-channel blockers address the pathophysiologic mechanisms of generic hypertension, thus providing clinicians with more specific pharmacologic tools for treating elderly hypertensives. In addition, these agents will avoid many of the side effects of other antihypertensive agents and can ameliorate certain concomitant diseases.

Factors associated with poor outcomes in patients with lupus nephritis.

The objective of this study was to identify the factors associated with important clinical outcomes in a case-control study of 213 patients with lupus nephritis. Included were 47% Hispanics, 44% African Americans and 9% Caucasians with a mean age of 28 years. Fifty-four (25%) patients reached the primary composite outcome of doubling serum creatinine, end-stage renal disease or death during a mean follow-up of 37 months. Thirty-four percent African Americans, 20% Hispanics and 10% Caucasians reached the primary composite outcome (P < 0.05). Patients reaching the composite outcome had predominantly proliferative lupus nephritis (WHO classes: 30% III, 32% IV, 18% V and 5% II, P < 0.025) with higher activity index score (7 +/- 6 versus 5 +/- 5, P < 0.05), chronicity index (CI) score (4 +/- 3 versus 2 +/- 2 unit, P < 0.025), higher baseline mean arterial pressure (MAP) (111 +/- 21 versus 102 +/- 14 mmHg, P < 0.025) and serum creatinine (1.9 +/- 1.3 versus 1.3 +/- 1.0 mg/dL, P < 0.025), but lower baseline hematocrit (29 +/- 6 versus 31 + 5%, P < 0.025) and complement C3 (54 +/- 26 versus 65 + 33 mg/dL, P < 0.025) compared to controls. More patients reaching the composite outcome had nephrotic range proteinuria compared to controls (74% versus 56%, P < 0.025). By multivariate analysis, CI (hazard ratio [95% CI] 1.18 [1.07-1.30] per point), MAP (HR 1.02 [1.00-1.03] per mmHg), and baseline serum creatinine (HR 1.26 [1.04-1.54] per mg/dL) were independently associated with the composite outcome. We concluded that hypertension and elevated serum creatinine at the time of the kidney biopsy as well as a high CI are associated with an increased the risk for chronic renal failure or death in patients with lupus nephritis.

Combined use of nifedipine and diltiazem for the treatment of severe hypertension.

Calcium channel blockers are a heterogeneous group of drugs that have enhanced our ability to concurrently control blood pressure, treat coronary artery disease, and avoid many of the side effects of previously available antihypertensive agents. Patients with severe hypertension may require multiple agents for adequate control of blood pressure because of either poor control with one agent or side effects from high doses of a single agent. Laboratory investigations have shown a synergistic effect on receptor binding, as well as increased drug levels with the concurrent use of diltiazem and a dihydropyridine calcium channel blocker (nifedipine or nicardipine). It is as yet unknown whether these effects on receptor binding and increased drug levels translate into greater clinical efficacy in blood pressure control. We have reported what we believe to be the first case in which this interaction was used successfully to control previously poorly controlled hypertension, while minimizing side effects.