Prolidase deficiency: case reports of two Argentinian brothers
Authors: Cabrera Hugo N. , Giovanna Patricia Della , Bozzini Natalia F. , Forlino Antonella 
Published: September 2004

Case 1

A 28‐year‐old man presented with his first leg ulcer at the age of 10 years. With regard to the family history, there was no consanguinity between the parents, and the patient had a brother with similar findings. He had frequent infections in childhood, such as otitis media, tuberculosis, and septic arthritis. At the age of 11 years, he showed photosensitivity, malar erythema, and positive antinuclear antibody test (1 : 40), and systemic lupus erythematosus was diagnosed (Fig. 1). This disease was later ruled out because diagnostic criteria were not present.

Photosensitivity and malar erythema at the age of 11 years (Case 1)

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At the age of 12 years, the ulcers worsened and did not respond to different treatments (antimicrobials, prednisone), and a diagnosis of pyoderma gangrenosum was suggested. Nevertheless, histopathology rejected such a diagnosis. The disease progressed until the patient presented again to our department.

On examination, the ulcers were located on both legs and thighs, had a polygonal form, elevated borders, and necrotic base (Fig. 2). They showed edema and induration with multiple scars. Dystrophic nails, saddle nose, hypertelorism, syndactyly, obesity, and deformity of the auricle were observed. Laboratory analysis revealed iron deficiency anemia (hematocrit, 30%), an erythrocyte sedimentation rate of 120 mm/h, an elevated gammaglobulin level (3.79 g%), and an elevated immunoglobulin E (IgE) (3285 U/L). Skin cultures were negative. The rest of the laboratory studies were normal (creatinine, glucose, C3, C4, negative HIV, and normal abdominal examination). The evaluation of cellular and humoral immunity showed normal results; chromosome studies disclosed no abnormalities.

Polygonal and deep ulcers on the left thigh (Case 1)

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A skin biopsy showed no specific abnormalities, except fibroblastic proliferation, inflammation, and ulcers that infiltrated the hypodermis. No signs of vasculitis were found. Multiple histologic analyses had been performed throughout the patient's life without any different findings.

Aliquots of urine from the patient and controls were analyzed by capillary zone electrophoresis (CZE) according to the method proposed by Zanaboni et al. (Zanaboni G, Grimm KM, Dyne KM, et al. Use of capillary zone electrophoresis for analysis of iminodipeptides in urine of prolidase‐deficient patients. J Chromatogr B 1996; 683: 97–107.) The presence of a large amount of dipeptides, normally absent from control samples, was detected in the patient.

There is no specific or effective treatment for prolidase deficiency, but the patient received oral and topical antimicrobials, oral prednisone, 1 mg/kg/day, and thalidomide, 200 mg/day, for 8 months in order to decrease the size of the ulcers and to improve his life quality. Unfortunately, treatment failed.

Case 2

The 23‐year‐old younger brother showed his first lesion at the age of 8 years. He had smaller leg ulcers than his brother, but they were pruriginous (Fig. 3). The round ulcers of 2–3 cm in diameter were on the inner part of the thighs. Laboratory analysis revealed hypergammaglobulinemia (26.3 g%), an erythrocyte sedimentation rate of 58 mm/h, splenomegaly, and elevated iminodipeptides in the urine. The evaluation of humoral and cellular immunity showed normal results. Skin biopsy showed no specific abnormalities, but fibrosis and perivascular inflammatory changes were present.

Rounded ulcers on the left thigh of the younger brother (Case 2)

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He was treated with topical antimicrobials, cortisone, and thalidomide, 200 mg/day, for 8 months without response.