Systemic sclerosis sine scleroderma: demographic, clinical, and serologic features and survival in forty-eight patients

OBJECTIVE

To describe the demographic, clinical, and laboratory features and natural history of patients with systemic sclerosis sine scleroderma (ssSSc), and to compare them with those of patients with SSc and limited cutaneous involvement (IcSSc).

METHODS

The University of Pittsburgh Scleroderma Databank served as the data source. Patients were divided into those who had no skin thickening (ssSSc) and those who had skin thickening only distal to elbows or knees and/or of the face (IcSSc) during their disease course. These two groups were compared with regard to demographic characteristics, clinical, laboratory, and serologic features, and survival rates. Chi-square and Student's t-test analyses were performed, and Fisher's exact test was used as appropriate.

RESULTS

Of 555 consecutive patients without diffuse cutaneous SSc, 48 (9%) had ssSSc and 507 (91%) had IcSSc. The ssSSc patients had a mean total disease duration of 18.6 years (15.1 years before study entry and 3.5 years of followup after study entry), and had not developed IcSSc or another connective tissue disease. Other than the absence of skin thickening, the ssSSc group had no significant differences in individual internal organ involvements, laboratory features, serum autoantibody type, or survival rate compared with patients with IcSSc. Within the category of lung involvement, patients with ssSSc had a significantly greater frequency of dyspnea with mild exertion or at rest, and a tendency toward reduced carbon monoxide diffusing capacity (<70% of predicted normal) and primary pulmonary arterial hypertension. Patients with IcSSc had significantly more frequent individual manifestations of digital pitting scars, digital-tip ulcers, telangiectasia, and calcinosis than those with ssSSc, in part related to increased time of observation. Puffy fingers and finger joint contractures were detected significantly more often in IcSSc patients.

CONCLUSION

Systemic sclerosis sine scleroderma should be included in the spectrum of SSc with limited cutaneous involvement and should not be considered a distinct or separate disorder.

Anti-RNA polymerase III antibodies in the diagnosis of scleroderma renal crisis sine scleroderma

We describe the use of antibodies to RNA polymerase III in the diagnosis of scleroderma in 2 patients who presented with renal crisis without other clinical features of the condition. Both presented with accelerated hypertension, rapidly progressive acute renal failure, microangiopathic hemolytic anemia, and thrombocytopenia. One patient developed digital infarcts in the course of his initial illness. Neither showed evidence of skin thickening at presentation. Nailfold capillaroscopy was normal in one patient and showed capillary dropout in the other. Renal biopsy showed findings consistent with thrombotic microangiopathy and both had anti-RNA polymerase III antibodies.

A novel cell-cycle-dependent 350-kDa nuclear protein: C-terminal domain sufficient for nuclear localization

We have screened human scleroderma patients for immunoreactivity with the components of the nucleus and the mitotic apparatus. We announce the identification of a novel cell-cycle-dependent nuclear protein using serum from a CREST patient AH. AH protein first appears at the nucleus of G2-phase and associates with the centrosome throughout the cell cycle. As chromosomes condense during the prophase, AH protein becomes enriched at the kinetochores. During mitosis, AH protein progressively disperses from the kinetochore and becomes diffusely localized in the cytoplasm and in telophase; it appears to be enriched within the intracellular bridge. Molecular cloning and transfection studies reveal that the 350-kDa AH protein contains a coiled-coil and a globular domain at the C-terminus that is sufficient for nuclear localization.

Elevated serum soluble interleukin-2 receptor levels in subacute cutaneous lupus erythematosus

Subacute cutaneous lupus erythematosus (SCLE) is a subset of lupus erythematosus which is characterized by unique cutaneous manifestations and immunological abnormalities. Soluble IL-2 receptor (sIL-2 R) is the shed product of membrane Il-2 R, a product of T cell activation. It is measured by enzyme-linked immunosorbent assay (ELISA) and has been found to correlate well with disease activity in systemic lupus erythematosus (SLE) patients. The objective of the present work was to determine whether there is a correlation between sIL-2 R levels and disease activity in SCLE. Serum samples were obtained from 25 SCLE patients and then measured for sIL-2 R levels of ELISA. Fifteen of 25 SCLE patients tested had normal levels of sIL-2 R, while 10 of 25 SCLE patients had elevated sIL-2 R levels. The serum sIL-2 R level in SCLE patients correlated well with disease activity and the number of American College of Rheumatology criteria for SLE. These findings indicate that sIL-2 R levels can be used as a valuable laboratory parameter in managing SCLE patients.