Photo-Hemolysis Associated with Protoporphyrinemia: Preliminary Report

Abstract

Since 1961 when Magnus, Jarrett, Prankard, and Rimington (1) first described a new disease entity, viz. erythropoietic protoporphyria, there have been reports of similar cases by several investigators (2, 3, 4, 5, 6). In all the reported cases, there were markedly elevated erythrocyte protoporphyrin levels associated with cutaneous photosensitivity. This form of photosensitivity may express itself in diverse cutaneous lesions including erythema, vesicles, wheals and eczema. We wish to report the preliminary results of studies concerning the in vitro hemolysis of red blood cells by ultraviolet light using cells from a patient having erythropoietic protoporphyrinemia. The patient is a seven year old girl who has vesicular and crusted skin lesions on the light exposed areas on and off since the age of 4 and who has been under our observation for the past 2 years. Erythrocyte protoporphyrin blood levels (7) were assayed on 4 occasions and were found to be significantly elevated. Preparation of Red Blood Cells for Hemolysis Studies: In each test run, the effects of ultraviolet light on the patient's red blood cells and on the red blood cells of a normal control subject were compared. Prior to irradiation, the cells were washed three times and resuspended in a 1:400 dilution of a 0.9% NaC1 phosphate buffer. Light Source: The red blood cells were irradiated with light from a bank of 4 Westinghouse F20 T12 BL blacklight fluorescent tubes. The emission spectrum of these tubes is mainly between 3200A° and 4500A°. In order to minimize the infrared radiation and the minute amount of radiation below 3200A the light was directed through a Corning 1-69 filter and through a window glass filter, 3 mm thick. The red blood cells were enclosed in quartz receptacles, and irradi* From the Department of Dermatology of New York University Schools of Medicine, New York, New York. This study was supported by Grant Number DA-49-193-MD-2275 from the U.S. Army Medical Research and Development Command. Technical Assistance given by Mary E. Moragne, B.S. Received for publication October 30, 1963. ated at a target distance of 6.25 centimeters. The intensity of the incident radiation was approximately 1100 microwatts per centimeter square. Measurement of Hemolytis was carried out by two methods: 1) direct cell counts: aliquots of the red blood cell suspensions were counted in a No. 500 Levy Counting Chamber (hemocytometer), at 10 minute intervals. Hemolysis was evident in the reduction of the number of red cells counted; 2) spectrophotometrically: the concentration of hemoglobin in the red blood cell supernatant was measured in a Coleman junior spectrophotometer.