Serum Cartilage Oligometric Matrix Protein and Pettersson Scoring System As an Index for Hemophilic Arthropathy

The pathogenesis of hemophilic arthropathy is multifactorial, with changes occurring in the synovium, bone, cartilage, and blood vessels. Recurrent joint bleeding causes synovial proliferation and inflammation (hemophilic synovitis) that contributes to end stage degeneration (hemophilic arthropathy); with pain and limitation of motion that severely affects patients’ quality of life.

The aim of the present study was to evaluate the degree of joint damage in boys with hemophilia using plain x-ray, and to measure serum level of human cartilage oligomeric matrix protein, to determine its relation to the degree of joint damage.

The study was carried out on thirty boys with hemophilic arthropathy (group I) and ten healthy boys were included as control (group II).

All hemophilic patients were scored for Functional independence score (FISH score) in hemophilia and radiological changes (Pettersson’s score) using conventional frontal and lateral radiographs of the most affected joint.

Factor activity level was measured for all hemophilic patients while serum cartilage oligomeric matrix protein (COMP) was measured for hemophilic patients and control group.

Among the thirty hemophilic patients, 26 (86.7%) patients were hemophilia A and 4 (13.3%) patients were hemophilia B

All patients were receiving on demand replacement therapy using plasma derived Factor concentrate or fresh frozen plasma (FFP) according to availability.

Fifteen patients (50%) had severe hemophilia, 7 (23.3%) had moderate and 8(26.72%) had mild hemophilia.

A higher serum level of COMP with a mean of 757± 211.30 in the severe hemophiliacs, and a mean of 403.57 ± 86.49 and 211.25 ± 74.26 in the moderate and mild hemophiliacs respectively the difference was statistically significant (p < 0.001).

Serum level of COMP in group I was significantly higher than in group II (p=0.004) with significant negative correlation with FISH score (r=-0.435 p=0.016). COMP correlated positively with joint space narrowing of the Pettersson score (r=0.421 p<0.001) and with total Pettersson score (r=0.421 p=0.020).

The number of joints affected (during life) of hemophilic patients ranged between 1-12 with a mean of 5.50 ± 2.46 Joints. A significant positive correlation between serum level of COMP and number of joints affected (r = 0.487, p = 0.006).

Joint space narrowing is the most important indicator of cartilage loss. Serum COMP level is indicative of the amount of joint damage in patients with hemophilic arthropathy.

The combined scoring of functional independence and Pettersson in addition with serum levels of COMP give a good overview of the degree of hemophilic arthropathy