Spectrum and diagnosis of idiopathic pulmonary fibrosis

OBJECTIVE

To study the clinical profile of patients with idiopathic pulmonary fibrosis (IPF) and methods used for diagnosis.

METHODS

Prospective analysis of symptoms, signs, radiology and lung biopsy of patients freshly diagnosed to have IPF over a 16-month period.

RESULTS

During the study period, 76 patients (35 men) with a mean age of 50.6 +/- 11.9 years were diagnosed to have IPE Breathlessness (98.6%) and dry cough (92.1%) were the most common presenting symptoms. Transbronchial lung biopsy (TBLB) was performed in 38 (50%) patients. Histopathological examination revealed features consistent with IPF in 35 (92.1%) patients; two of the remaining three patients underwent open lung biopsy. Other patients were diagnosed based on clinical features and high resolution chest tomography (HRCT) findings. HRCT was performed in 69 (90.8%) patients; all had features suggestive of diffuse interstitial fibrosis.

CONCLUSION

IPF is diagnosed more commonly now than in the past. Indian patients may be developing the disease a decade earlier than their counterparts in the West. TBLB and HRCT are useful in establishing diagnosis. IPF should be considered a distinct clinical entity rather than a diagnosis of exclusion.

Impaired growth and elevated fas receptor expression in PIGA(+) stem cells in primary paroxysmal nocturnal hemoglobinuria

The genetic defect underlying paroxysmal nocturnal hemoglobinuria (PNH) has been shown to reside in PIGA, a gene that encodes an element required for the first step in glycophosphatidylinositol anchor assembly. Why PIGA-mutated cells are able to expand in PNH marrow, however, is as yet unclear. To address this question, we compared the growth of affected CD59(-)CD34(+) and unaffected CD59(+)CD34(+) cells from patients with that of normal CD59(+)CD34(+) cells in liquid culture. One hundred FACS-sorted cells were added per well into microtiter plates, and after 11 days at 37 degrees C the progeny were counted and were analyzed for their differentiation pattern. We found that CD59(-)CD34(+) cells from PNH patients proliferated to levels approaching those of normal cells, but that CD59(+)CD34(+) cells from the patients gave rise to 20- to 140-fold fewer cells. Prior to sorting, the patients' CD59(-) and CD59(+)CD34(+) cells were equivalent with respect to early differentiation markers, and following culture, the CD45 differentiation patterns were identical to those of control CD34(+) cells. Further analyses of the unsorted CD59(+)CD34(+) population, however, showed elevated levels of Fas receptor. Addition of agonist anti-Fas mAb to cultures reduced the CD59(+)CD34(+) cell yield by up to 78% but had a minimal effect on the CD59(-)CD34(+) cells, whereas antagonist anti-Fas mAb enhanced the yield by up to 250%. These results suggest that expansion of PIGA-mutated cells in PNH marrow is due to a growth defect in nonmutated cells, and that greater susceptibility to apoptosis is one factor involved in the growth impairment.