150 LETTERS

Figure 1. Sural nerve biopsy specimen from a patient with systemic necrotizing vasculitis, showing no evidence of myelin degeneration or thrombosis of the blood vessel.

monocytes, and 4% eosinophils. The hematocrit value was 37.8% and the platelet count was 686,000 cells/mm3. The Westergren erythrocyte sedimentation rate was 68 mdhour . The albumin level was 2.7 gm/dl. Test results for C3, C4, antinuclear antibodies, rheumatoid factor, VDRL, hepatitis B antigen and antibodies, and cryoglobulins were negative or normal. Serum protein electrophoresis revealed hypoalbu- minemia without hypergammaglobulinemia. Serum lead lev- els were normal.

The patient underwent electromyography (EMG) and NCV studies, which revealed markedly decreased ve- locity in the right radial nerve and marked decreased ampli- tude with prolonged distal latency of both peroneal nerves. Results of studies of both sural nerves were normal.

Because of the high index of suspicion of a diagnosis of systemic vasculitis, high-dose oral corticosteroids, 1 mg/kg/day, were begun. Two days later, the patient under- went a sural nerve and quadriceps biopsy (Figure 1). These biopsy specimens revealed evidence of necrotizing vasculitis of medium-sized vessels compatible with a diagnosis of polyarteritis. There was no evidence of vascular thrombosis or of myelin degeneration.

We believe this case demonstrates that normal results on conduction studies of the sural nerve do not preclude the ability to make a diagnosis of systemic necrotizing vasculitis by biopsy. In a study by Wees et a1 (6), in which sural nerve biopsy is advocated for accurate diagnosis of systemic vascu- litis, 17 patients who presented with vasculitic neuropathy were investigated. All 17 had abnormal results on nerve conduction studies, and 15 had abnormal results on EMGs. Fourteen cases were diagnosed by sural nerve biopsy, 2 by muscle biopsy, and 1 by mesenteric angiography. No control population was studied. It was stated that “abnormal sural nerve conduction is a prerequisite to the demonstration of vasculitis on biopsy of this nerve” (6).

This concept has also been presented in standard rheumatology textbooks (8). The development of abnormal- ities related to vasculitis, seen on nerve conduction tests, is

believed to be secondary to epineural vascular infarction with subsequent nerve injury (3,5,7). It is possible that early in the course of vasculitic injury, transmural vascular inflam- mation occurs without infarction and subsequent myelin damage. If so, results of the nerve conduction studies may be normal. We believe that this happened in our patient, and it indicates that early in the diagnostic process of patients with suspected vasculitic neuropathy, a normal sural nerve conduction study result should not preclude a biopsy to establish the diagnosis.

James R. Davidson, MD Walter R. Sundstrom, MD, FACP University of Wisconsin W.S. Middleton Veterans Hospital Madison. WI

1.

2.

3.

4.

5 .

6.

7.

8.

Moore PM, Fauci AS: Neurologic manifestations of systemic vasculitis. Am J Med 71517-524, 1981 Cohen RD, Conn DL, llstrup DM: Clinical features, prognosis and response to treatment in polyarteritis. Mayo Clin Proc

Moore PM, Cupps TR: Neurological complications of vasculitis. Ann Neurol 14:155-167, 1983 Chang RW, Bell CW, Hallett M: Clinical characteristics and prognosis of vasculitis mononeuropathy multiplex. Arch Neurol

Conn DL, McDuffie FC, Dyck PJ: Immunopathologic study of sural nerves in rheumatoid arthritis. Arthritis Rheum 15: 135-143, 1972 Wees ST, Sunwoo IN, Oh SJ: Sural nerve biopsy in systemic necrotizing vasculitis. Am J Med 71525-532, 1981 Kissel JT, Slivka AP, Warmolts JR, Mendell JR: The clinical spectrum of necrotizing vasculitis of the peripheral nervous system. Ann Neurol 18:251-257, 1985

Conn DL, Hunder GG: Necrotizing vasculitis, Textbook of Rheu- matology. Second edition. Edited by WN Kelley, ED Hams Jr, S Ruddy, CB Sledge. Philadelphia, WB Saunders, 1981, pp 1137- 1166

551146-155, 1980

41~618-621, 1984

Comment on the article by Lahita et al

To the Editor: I read with interest the article by Lahita et a1 regard-

ing their finding of low plasma androgen levels in systemic lupus erythematosus (SLE) patients (1). They demonstrated this to be the case in women and suggested that it was possibly the case in men. I wish to raise a few additional considerations:

1. Androgen levels were determined in only 5 male patients in Lahita’s study (Table 3), and these patients were divided into those with inactive SLE (2 patients) and those with active SLE (3 patients). The information is overempha- sized in view of the small numbers. The authors did not cite 2 studies, including a total of 28 male SLE patients, in which no androgen deficiencies were found (2,3).

2. Patients taking corticosteroids were evaluated separately because of the drugs’ obvious effects on androgen levels. However, there is no evidence that patients were

LETTERS 151

questioned as to whether they were taking oral contracep- tives or conjugated estrogens (e.g., for treatment of steroid- induced osteoporosis), both of which might also influence androgen levels.

3. In Table 1, the patients’ levels of disease activity are classified. The serologic data given in Table 2 are purported to “confirm the clinical impression of disease activity.” In fact, they do not. The mean CH50 level was 165 units in the female, inactive disease group and 161 units in the female, active disease group. Anti-DNA levels were only slightly higher in the active disease group; the difference is probably not statistically significant, and these values were determined in only 13 of the 36 patients in the non-steroid- treated subset described in the table.

4. The premise that low plasma androgen levels in women with SLE are of pathophysiologic importance and can affect immune regulation is a challenging concept that needs to be qualified: Our group found that the survival curves of 63 men with SLE showed far greater rates of mortality than those of 546 women with the disease, over a 30-year period (P < 0.005) (4). The question remains as to why men with lupus often have more severe disease.

Daniel J. Wallace, MD Los Angeles, CA

1. Lahita RG, Bradlow HL, Ginzler E, Pang S, New M: Low plasma androgens in women with systemic lupus erythematosus. Arthritis Rheum 30:241-248, 1987

2. Stahl NI, Decker JL: Androgenic status of males with systemic lupus erythematosus. Arthritis Rheum 21:665-668, 1978

3. Inman RD, Jovanovic L, Markenson JA, Longcope C, Dawood MY, Lockshin MD: Systemic lupus erythematosus in men: genetic and endocrine features. Arch Intern Med 142: 1813-1815, 1982

4. Wallace DJ, Podell T, Weiner J , Klinenberg JR, Forouzesh S, Dubois EL: Systemic lupus erythematosus-survival patterns: experience with 609 patients. JAMA 245:934-938, 1981

Reply

To the Editor: We would like to reply to Dr. Wallace’s comments

regarding our recently published article (1). 1. The findings on androgen levels in men were

stated as being inconclusive because of the low numbers studied. As was written, only dehydroepiandrosterone and dehydroepiandrosterone sulfate levels were lower than those observed in normal men. No differences of testosterone or androstenedione were observed in any man studied. This is consistent with the findings of Stahl and Decker ( 2 ) , who measured testosterone and gonadotrophin levels, and is in contrast with those of Inman et a1 (3), who studied only 8 men and found more significant androgen deficits in at least 5 of them. We clearly state that the statistics on men are meaningless because of the small numbers.

2. None of the female patients in our study were taking oral contraceptives or conjugated estrogens for osteo-

porosis; we agree that such levels can influence disease activity. Oral contraceptives are never prescribed for our systemic lupus erythematosus (SLE) patients because of the known risk for disease exacerbation associated with these agents (4). Moreover, we have studied SLE patients who have formerly taken such agents and have documented abnormalities of immunity (5).

3. It is very difficult to establish legitimate para- meters of clinical activity in SLE, and this is reflected in Table 2 of our report. All clinicians would agree that activity is best measured by clinical signs which are supported by laboratory data. In most instances, we utilize both criteria in the classification of activity. The data in Table 2 reflect the facts that several patients with very active SLE had CH50 values that were within the normal range and that anti-DNA values in the active disease population also varied. This was the principal reason for inclusion of the activity scale data (Table I), which describe the status of individual patients. We agree that a uniform index of clinical activity is needed by all clinicians who treat SLE patients and that such an index cannot rely on laboratory values alone.

4. The idea that male SLE patients have worse disease than do females is not universally accepted (ref. 6 and Sthoeger ZM, Geltner D, Rider A, Bentwich Z: unpub- lished observations), even though the data from several groups are provocative. The reasons for the occurrence of SLE in men are still unknown, although the data on humans certainly favor depressed androgen levels and elevated es- trogen levels as a possible cause (1,7,8). It is possible that the study results differ because of genetic differences asso- ciated with the geographic origins of patient populations.

Robert G. Lahita, MD, PhD H. Leon Bradlow, PhD The Rockefeller University New York, NY Songya Pang, MD Maria New, MD Cornell University Medical College New York, NY Ellen Ginzler, MD Downstate Medical Center Brooklyn, NY

1 . Lahita RG, Bradlow HL, Ginzler E, Pang S, New M: Low plasma androgens in women with systemic lupus erythematosus. Arthritis Rheum 30241-248, 1987

2. Stahl NI, Decker JL: Androgenic status of males with systemic lupus erythematosus. Arthritis Rheum 21:665-668, 1978

3. Inman RD, Javonovic L, Markenson JA, Longcope C, Dawood MY, Lockshin MD: Systemic lupus in men: genetic and endo- crine features. Arch Intern Med 142:1813-1815, 1982

4. Chapel TA, Burns RE: Oral contraceptives and exacerbation of SLE. Am J Obstet Gynecol 110:366-369, 1971

5. Bucala R, Lahita RG, Fishman J , Cerami A: Anti-estrogen antibodies in users of oral contraceptives and in patients with systemic lupus erythematosus. Clin Exp Immunol 67: 167-175, 1987

6. Miller MH, Urowitz MB, Gladman DD, Killinger DW: Systemic lupus erythematosus in males. Medicine (Baltimore) 62:327-334, 1983